If One of These Stars Explodes the Radioactive Atoms Could Decimate Life on Earth

Most of these cataclysms are remote, but when they occur closer to home, they can pose a threat to life on Earth.

by Chris Impey and The Conversation

 

NASA

The Sun will eventually die by growing large and then condensing into a type of star called a white dwarf. But stars more than eight times more massive than the Sun die violently in an explosion called a supernova.

Supernovae happen across the Milky Way only a few times a century, and these violent explosions are usually remote enough that people here on Earth don’t notice. For a dying star to have any effect on life on our planet, it would have to go supernova within 100 light years from Earth.

I’m an astronomer who studies cosmology and black holes.

In my writing about cosmic endings, I’ve described the threat posed by stellar cataclysms such as supernovae and related phenomena such as gamma-ray bursts. Most of these cataclysms are remote, but when they occur closer to home, they can pose a threat to life on Earth.

The death of a massive star

Very few stars are massive enough to die in a supernova. But when one does, it briefly rivals the brightness of billions of stars. At one supernova per 50 years, and with 100 billion galaxies in the universe, somewhere in the universe a supernova explodes every hundredth of a second.

The dying star emits high energy radiation as gamma rays. Gamma rays are a form of electromagnetic radiation with wavelengths much shorter than light waves, meaning they’re invisible to the human eye. The dying star also releases a torrent of high-energy particles in the form of cosmic rays: subatomic particles moving at close to the speed of light.

Supernovae in the Milky Way are rare, but a few have been close enough to Earth that historical records discuss them. In 185 A.D., a star appeared in a place where no star had previously been seen. It was probably a supernova.

Observers around the world saw a bright star suddenly appear in 1006 A.D. Astronomers later matched it to a supernova 7,200 light years away. Then, in 1054 A.D., Chinese astronomers recorded a star visible in the daytime sky that astronomers subsequently identified as a supernova 6,500 light years away.

Johannes Kepler observed the last supernova in the Milky Way in 1604, so in a statistical sense, the next one is overdue.

At 600 light years away, the red supergiant Betelgeuse in the constellation of Orion is the nearest massive star getting close to the end of its life. When it goes supernova, it will shine as bright as the full Moon for those watching from Earth, without causing any damage to life on our planet.

Radiation damage

If a star goes supernova close enough to Earth, the gamma-ray radiation could damage some of the planetary protection that allows life to thrive on Earth. There’s a time delay due to the finite speed of light. If a supernova goes off 100 light years away, it takes 100 years for us to see it.

Astronomers have found evidence of a supernova 300 light-years away that exploded 2.5 million years ago. Radioactive atoms trapped in seafloor sediments are the telltale signs of this event. Radiation from gamma rays eroded the ozone layer, which protects life on Earth from the Sun’s harmful radiation. This event would have cooled the climate, leading to the extinction of some ancient species.

Safety from a supernova comes with greater distance. Gamma rays and cosmic rays spread out in all directions once emitted from a supernova, so the fraction that reach the Earth decreases with greater distance. For example, imagine two identical supernovae, with one ten times closer to Earth than the other. Earth would receive radiation that’s about a hundred times stronger from the closer event.

A supernova within 30 light-years would be catastrophic, severely depleting the ozone layer, disrupting the marine food chain, and likely causing mass extinction. Some astronomers guess that nearby supernovae triggered a series of mass extinctions 360 to 375 million years ago. Luckily, these events happen within 30 light years, only every few hundred million years.

When neutron stars collide

But supernovae aren’t the only events that emit gamma rays. Neutron star collisions cause high-energy phenomena ranging from gamma rays to gravitational waves.

Left behind after a supernova explosion, neutron stars are city-size balls of matter with the density of an atomic nucleus, so 300 trillion times denser than the Sun. These collisions created many of the gold and precious metals on Earth. The intense pressure caused by two ultradense objects colliding forces neutrons into atomic nuclei, which creates heavier elements such as gold and platinum.

A neutron star collision generates an intense burst of gamma rays. These gamma rays are concentrated into a narrow jet of radiation that packs a big punch.

If the Earth were in the line of fire of a gamma-ray burst within 10,000 light years, or 10% of the diameter of the galaxy, the burst would severely damage the ozone layer. It would also damage the DNA inside organisms’ cells at a level that would kill many simple life forms like bacteria.

That sounds ominous, but neutron stars do not typically form in pairs, so there is only one collision in the Milky Way about every 10,000 years. They are 100 times rarer than supernova explosions. Across the entire universe, there is a neutron-star collision every few minutes.

Gamma-ray bursts may not hold an imminent threat to life on Earth, but over very long time scales, bursts will inevitably hit the Earth. The odds of a gamma-ray burst triggering a mass extinction are 50% in the past 500 million years and 90% in the 4 billion years since there has been life on Earth.

By that math, it’s quite likely that a gamma-ray burst caused one of the five mass extinctions in the past 500 million years. Astronomers had argued that a gamma-ray burst caused the first mass extinction 440 million years ago when 60% of all marine creatures disappeared.

A recent reminder

The most extreme astrophysical events have a long reach. Astronomers were reminded of this in October 2022 when a pulse of radiation swept through the solar system and overloaded all of the gamma-ray telescopes in space.

It was the brightest gamma-ray burst to occur since human civilization began. The radiation caused a sudden disturbance to the Earth’s ionosphere, even though the source was an explosion nearly 2 billion light years away. Life on Earth was unaffected, but the fact that it altered the ionosphere is sobering – a similar burst in the Milky Way would be a million times brighter.

• This article was originally published on The Conversation by Chris Impey at the University of Arizona. Read the original article here.

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09-09-2024 om 22:20 geschreven door peter  

If This Asteroid Hits Earth then we will all Die | NASA Warns About Asteroid coming in 2038

Hera will investigate further

Now, who's going to clean up this mess? Enter ESA's Hera spacecraft. Scheduled for launch this October, Hera will reach Dimorphos for a close-up "crash scene investigation," following the DART mission's impact.

"The DART impact offers a rare opportunity to investigate the delivery of ejecta to other celestial bodies, thanks to the fact that we know the impact location and that this impact was observed by the Italian LICIACube deployed from DART as well as by Earth-based observers," said ESA Hera mission scientist and co-author of this exciting development, Michael Kueppers.

Will DART debris reach Earth?

To understand how the debris from the Dimorphos impact might reach us, it's essential to assess its speed.

"Our results indicate the possibility of ejecta reaching the gravitational field of Mars in 13 years for launch velocities around 450 m/s, while faster ejecta launched at 770 m/s could reach its vicinity in just seven years," explained Eloy Peña-Asensio, lead author of the study.

"Particles moving above 1.5 km/s could reach the Earth-Moon system in a similar timescale."

However, whether the debris would indeed make it to Mars or Earth is subject to several factors. In essence, the location of the debris in the impact plume plays a deciding role.

A human-made meteor shower

"In the coming decades, meteor observation campaigns will be crucial in determining whether fragments of Dimorphos, resulting from the DART impact, will reach our planet. If this happens, we will witness the first human-made meteor shower," noted Peña-Asensio.

As for the consequential meteoroids, the largest ones would likely be about the size of a softball. These larger particles would burn up in Earth's atmosphere. However, they might manage to slip through the thinner Martian atmosphere.

However, it's the smaller particles that move at higher speeds which stand a chance to reach the Earth's atmosphere. But there's no need to panic. We have plenty of time and resources to track the debris and ensure our safety.

Significance of the DART mission

The significance of the DART impact is not solely about potential meteor showers or altered space debris routes. It's also about the human spirit of curiosity, exploration, and conquering new frontiers.

"Our accurate knowledge of the impact site and impactor properties in terms of size, mass, and velocity plus the observations of the ejecta are what allowed us to estimate the long-term fate of the material leaving the Didymos system," said Michael Kueppers.

Hera, named after the Greek goddess of marriage, is expected to begin its investigation of the asteroid pair in late 2026. According to ESA, the spacecraft will perform high-resolution mapping of Dimorphos, providing extremely valuable information for future asteroid deflection missions and science.

DART Impact

The last complete image of asteroid moonlet Dimorphos was taken by the DRACO imager on NASA's DART mission at a distance of about 7 miles (12 kilometers) and 2 seconds before impact. 

NASA/Johns Hopkins APL

09-09-2024 om 21:51 geschreven door peter  

Minute by minute, what would happen if a world-destroying asteroid was detected coming to Earth - after 'greenish' space fireball crashed into our planet this week

• READ MORE: Moment asteroid hits Earth's atmosphere like a ball of fire

By Matthew Phelan and Stacy Liberatore For Dailymail.com

NASA's radar gives off a ping, notifying scientists that a world-destroying asteroid has been detected and could hit Earth in 10 years.

World governments are quickly alerted about a potentially catastrophic event, allowing them to formulate a plan to inform the public.

One year before impact, space agencies from every country launch nuclear deflection missiles with hopes of pushing the giant asteroid away from our planet - but the mission fails.

FEMA orders mass evacuations in the impact zone months in advance and the public is told to expect the worst with hours left on the clock.

While NASA has said such a scenario is unlikely to happen in the near future, an asteroid hit Earth this week and was detected only eight hours before impact.

An asteroid hit Earth on Thursday that was detected on eight hours before impact. However, NASA would have about 10 years to save the world from a world-destroying space rock 

Most asteroids are not on track to hit Earth - but in the event that one is, here above is the sequence of events that would spring into action after the space rock is spotted

The small space rock that soared over the Philippines on Thursday was only three feet in diameter, which was not large enough to sound any alarms.

A report published by the White House in 2021 recommended that a reconnaissance mission would be necessary if an asteroid measuring at least 165 feet could hit Earth within 50 years is detected.

The document categorized a 3,300-foot-wide asteroid as a 'possible global catastrophe,' a three-mile-wide space rock as 'above the global catastrophe threshold,' and a six-mile-wide object as capable of causing a 'mass extinction.' 

However, NASA, FEMA, and the United Nations conducted an exercise in April to assess how prepared Earth would be if a world-destroying asteroid were detected, finding that we would need at least 14 years' notice. 

Detecting the world-destroying asteroid - 10 years out

Read More

• Chunks of asteroid from NASA's deflection test could smash into Earth in the next 10 years 

NASA's ground-based telescopes identify the giant asteroid, comparing it with other space rocks in a database to ensure it is newly discovered.

The space agency has several projects that scan the skies, including the Catalina Sky Survey which spotted Thursday's asteroid.

These early-warning systems also include NEOWISE (Near-Earth Object Wide-field Infrared Survey Explorer), a spacecraft equipped with a wide-field, 20-inch infrared telescope that operates in two wavelength ranges.

Once the object is detected, astronomers look at the data for brightness and movement to double-check that it is not a known one.

Teams then report their findings to the Minor Planet Center (MPC), the single worldwide location for reporting asteroids, minor planets and comets.

The MPC and NASA team up to determine the asteroid's orbit to predict if the path poses a threat to Earth. 

The team discovers that the space rock is likely to come within five million miles of our planet and sends alerts to other agencies around the world, according to NASA.

Now that the world is aware of the impending threat, space agencies from every country join forces to deflect the asteroid about two years after detection. 

A report published by the White House in 2021 categorized asteroid sizes, deeming one at least 3,300 feet wide could be catastrophic

The scenario begins with NASA detecting a world-destroying asteroid 10 years before it hits Earth. The agency has telescopes around the globe, like Catalina Sky Survey in Arizona that detected Thursday's asteroid that hit our planet

Launching an asteroid deflection - two to five years before impact

NASA tested a strategy in 2022 called the Double Asteroid Redirection Test (DART) that plowed into an asteroid at 14,000 miles per hour, leaving a massive plume of dust and rocks, and successfully altering its trajectory.

That asteroid did not threaten our planet, but the space agency could use the strategy to deflect the world-destroying asteroid.

This February, however, NASA's planetary defense chief warned that a DART-like mission would not be able to get off the ground if the impact needed to occur in less than five years.

Leading up to the launch of humanity's Hail Mary, NASA and international partners are studying a range of options, including a spacecraft and nuclear weapons. 

The group decides to attack the asteroid with nuclear bombs about five years after detection and begins testing a prototype. 

Then, two years before impact, teams send explosives and a detonation device at some short standoff distance from the asteroid.

Kaliat Ramesh, a professor of mechanical engineering and material science at Johns Hopkins University, told VOX: 'We would estimate that it would take energy equivalent to about 200 gigatons of TNT to fully disrupt an asteroid with a 12-mile diameter.' 

One gigaton is equal to one billion tons of TNT, which means we would need 10 million Hiroshima-size bombs to destroy the massive asteroid hurtling toward Earth.

The only rockets capable of carrying such massive payloads of nuclear bombs would likely be NASA's Space Launch System (SLS) and Elon Musk's SpaceX Starship, but neither have been proven in this type of mission.

One year before impact, space agencies from every country launch nuclear deflection missiles with hopes of pushing the massive asteroid away from our planet

Billy Bob Thornton as Dan Truman, a a scientist at NASA, in Armageddon. Although a trope of sci-fi films, deflecting asteroids bound for Earth is a real concern 

The nuclear option would be faster, a concept familiar to fans of the 1998 film Armageddon, starring Bruce Willis and Ben Affleck. 

In the movie, NASA sends a group of deep-sea drillers to blow up an Earth-bound asteroid and save humanity with just 18 days of lead time. 

Evacuation Plan - months to hours before impact

In the months leading up to impact, global organizations like the Planetary Defense Coordination Office (PDCO) would create detailed impact scenarios, estimating the destruction radius, atmospheric effects and potential global consequences.

Refined calculations forecasting the exact spot where an asteroid would impact Earth would, however, only become available as the asteroid comes into radar range, a process that new deep-space radar could accelerate. 

FEMA would order evacuations around the impact zone to save as many lives as possible

And hours before the asteroid makes impact, the world will be told to shelter-in-place and hope for the best

The information collected by global organizations is sent to FEMA and other emergency groups to alert people in the impact zone, allowing for mass evacuations months before the space rock smashes into Earth.

Teams would also begin formulating rescue plans and assembling relief teams that would be deployed almost immediately after impact to salvage as many lives as possible.

A NASA report published in 2023 estimated that everyone within 300 miles of the impact zone, about 150 million people, 'would need to either evacuate or find an appropriate shelter or build one.'

As the clock ticks down to hours, the public would be ordered to shelter in place while they receiving continuous updates and directions.  

After impact 

The asteroid impact would cause widespread devastation, triggering tsunamis that devastate coastal regions and massive shockwaves and earthquakes.

Electrical and communication systems around the globe fail almost instantly. 

The plan to save Earth would include a deflection strategy, evacuations and shelter-in place

The sun has been blocked by a massive dust plume released from impact, causing a significant drop in temperatures and a 'nuclear winter' that could last for decades.

Earth would be shrouded in darkness as massive fires rage that deplete oxygen levels. 

Billions of people are dead, but those who did survive are now suffering from starvation, freezing temperatures and the collapse of civilization’s infrastructure. 

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09-09-2024 om 18:12 geschreven door peter  

By Dan Woodland

Boeing's Starliner has returned to Earth empty after leaving two astronauts who rode the spaceship up to the International Space Station stranded until next year.

The space capsule touched down at the White Sands Space Harbor in New Mexico today at approximately 4am GMT, around six hours after departing the ISS on Friday. 

It was due to return to earth much earlier, having launched in June for what was meant to be a roughly weeklong test mission with astronauts Butch Wilmore and Suni Williams on board. 

But unexpected thruster malfunctions and helium leaks on its way up derailed those plans and NASA ultimately decided it was safer to bring the pair back on a spacecraft from rival Elon Musk's SpaceX. 

The next scheduled SpaceX flight is not until February next year, meaning Wilmore and Williams will be stranded in space for another six months. 

Boeing's Starliner lands at the landing site at White Sands Space Harbor in White Sands, New Mexico

Astronauts Butch Wilmore and Suni Williams were initially planned to depart on the Starliner, but issues with the capsule's thrusters have delayed their return until at least February 2025

Ground teams reported hearing sonic booms as it streaked red hot across the night sky, having endured temperatures of 3,000F (1,650C) during atmospheric reentry.

A smooth, uneventful ride was seen as critical not only for salvaging some pride but also for Boeing's prospects of achieving certification in the future.

The century-old aerospace giant had carried out extensive ground testing aimed at replicating the technical issues the spaceship had experienced on its ascent and devised plans to prevent more problems.

With its reputation already battered by safety concerns affecting its passenger jets, Boeing made assurances in public and in private that it could be trusted to bring the astronauts home - an assessment not shared by NASA.

'Boeing believed in the model that they had created that tried to predict the thruster degradation for the rest of the flight,' Steve Stich, program manager for NASA's Commercial Crew Program, told reporters this week.

But 'the NASA team, due to the uncertainty in the modeling, could not get comfortable with that,' he added, characterizing the mood during meetings as 'tense.'

The gumdrop-shaped capsule touched down softly at the White Sands Space Harbor in New Mexico, its descent slowed by parachutes and cushioned by airbags

Shortly after undocking, Starliner executed a powerful 'breakout burn' to swiftly clear it from the station and prevent any risk of collision - a maneuver that would have been unnecessary if crew were aboard to take manual control if needed.

Following that, mission teams conducted thorough checks of its thrusters in preparation for the critical 'deorbit burn,' required to guide the capsule onto its reentry path around 40 minutes before landing.

While expectations were high that Starliner would stick the landing, as it had in two previous uncrewed tests, NASA will now carefully review all aspects of the mission's performance before deciding on the next steps.

NASA awarded Boeing and SpaceX multibillion-dollar contracts over a decade ago to develop spacecraft to taxi astronauts to and from the ISS, after the end of the Space Shuttle program left the US space agency reliant on Russian rockets.

Although initially considered the underdog, Elon Musk's SpaceX surged ahead of mighty Boeing, successfully flying dozens of astronauts since 2020.

The Starliner program, meanwhile, has faced numerous setbacks.

The space capsule touched down at the White Sands Space Harbor in New Mexico today at approximately 4am GMT, around six hours after departing the ISS on Friday

Boeing and NASA teams working around NASA's Boeing Crew Flight Test Starliner spacecraft after it landed uncrewed at White Sands, New Mexico

A full timeline of Boeing's Starliner program, from the singing of their massive contact to the incident that left two astronauts stranded aboard the ISS 

In 2019, during its first uncrewed test flight, a software glitch prevented the capsule from rendezvousing with the ISS. A second software issue, which could have caused a catastrophic collision between its modules, was caught and fixed just in time.

In 2021, with the rocket poised on the launchpad for another attempt, blocked valves forced yet another postponement.

The capsule finally reached the ISS in May 2022 on a non-crewed flight, but further issues, including weak parachutes and flammable tape in the cabin that needed removal, delayed the crewed test.

For the current mission, astronauts Wilmore and Williams had been strapped into their seats and ready to fly twice before last-minute 'scrubs' due to technical glitches sent them back to their quarters.

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09-09-2024 om 17:52 geschreven door peter  

Revealed: The 6 catastrophic asteroids on course to crash into Earth - as a 'surprise' space rock burns up over the Philippines

• Experts reveal the asteroids with the highests chances of destroying humanity
• One asteroid has a chance of hitting Earth by October 5 this year 
• READ MORE: Watch moment asteroid hits Earth's atmosphere like a ball of fire 

By Wiliam Hunter

Scientists around the world were caught off guard on Wednesday as a previously undetected asteroid collided with Earth's atmosphere. 

The one metre (3ft) wide asteroid was spotted just eight hours before it burned up over the Philippines in a spectacular fireball.

Luckily, the asteroid, named 2024 RW1, was too small to cause any damage. 

However, its sudden arrival is a stark reminder of the dangers lurking within our solar system.

From the so-called 'Valentine's Day asteroid' to the deadly space rocks almost a mile wide, experts warn that several asteroids are at risk of smashing into Earth. 

From the so-called 'Valentine's Day asteroid' to the deadly space rocks almost a mile wide, experts warn that several asteroids are at risk of smashing into Earth 

Scientists around the world were caught off guard on Wednesday as a previously undetected asteroid collided with Earth's atmosphere

Asteroids colliding with Earth is far from an uncommon event. 

In fact, NASA estimates that about 48.5 tonnes of meteoric material falls on Earth each day.

However, the vast majority of these objects simply burn up in the atmosphere to produce the flashing lights we recognise as shooting stars.

Objects large enough to punch through the atmosphere and actually collide with Earth are far rarer and don't often come within Earth's orbit.

Of course, just because asteroid collisions are unlikely, it does not mean they are impossible - and Earth already bears the scars of several such events.

Most famously, 66 million years ago a six-mile-wide (9.65km) asteroid crashed into the Yucatán peninsula in Mexico - wiping out the dinosaurs and leaving behind a 115-mile (185km) wide crater.

Even smaller rocks can have a devastating impact, as shown by the Chelyabinsk meteor, a 59 ft (18m) wide asteroid which exploded over Russia in 2013.

Despite being hundreds of times smaller than the meteor that killed the dinosaurs, the resulting shockwave injured 1,500 and damaged 7,300 buildings.

Due to these risks, NASA and the European Space Agency (ESA) operate programs aimed at identifying, categorising, and tracking so-called Near Earth Objects (NEOs).

Currently, ESA has 1,634 NEOs on its 'risk list' - meaning that there is a non-zero chance these objects will hit Earth.

However, at present no asteroid is ranked above one on the Torino Scale - a chart which ranges from 0 (won't hit Earth) to 10 (will hit Earth, and will be catastrophic). 

The Earth has been hit by devastating asteroids in the past such as the Chicxulub asteroid, which slammed into a shallow sea in what is now the Gulf of Mexico around 66 million years ago, creating an explosion that wiped out the dinosaurs

Experts say that another asteroid impact with Earth is a matter of when, not if (stock image) 

Read More

•  Moment asteroid hits Earth's atmosphere like a ball of fire 

1. Bennu

Discovered in September 1999, the asteroid Bennu is currently considered to pose one of the biggest risks to Earth.

At 1,574ft (0.49km) in diameter and weighing 67 million tonnes, Bennu is wider than the Empire State Building is tall and weighs 200 times as much.

Thanks to careful observation by NASA, scientists currently believe that Bennu has a one in 2,700 chance of hitting Earth on September 24, 2182.

If it were to collide with the planet, it would release energy equivalent to 1.4 billion tonnes of TNT.

Professor Dante Lauretta of the University of Arizona previously said that an impact with Bennu would release 'three times more energy than all nuclear weapons detonated throughout history'.

While this might not be quite enough to create the type of planet-destroying force which wiped out the dinosaurs it could still lead to millions of deaths.

The asteroid Bennu (pictured) is considered to pose the biggest threat to Earth and could hit our planet within the next 200 years  

However, before you head to the bunkers, NASA's predictions of impact chance become more accurate the closer the asteroid comes to Earth.

So, with more than 150 years until its next close approach, it is likely that those odds may change quite significantly in the future.

Due to its size and risk to Earth, the asteroid has been the attention of intense scientific study.

In 2023, NASA's OSIRIS REx spacecraft managed to return a sample of the space rock to Earth.

This revealed that Bennu may contain the building blocks of life - including possible sources of water.

2. 2023 DW - The Valentine's Day asteroid

Forgetting the chocolates and flowers on Valentine's Day 2046 might be the least of your worries.

The asteroid 2023 DW is predicted to have a significant chance of colliding with Earth on February 14, 2046 - just in time to ruin your date plans.

At 166ft (50m) across, 2023 DW is about the same size as the asteroid that caused the devastating Chelyabinsk event back in 2013.

The Valentine's Day asteroid, 2023 DW, (pictured) has a slim possibility of hitting Earth on February 14, 2046

Given that the asteroid has been observed moving at 21.78 km/s relative to the sun, it could hit Earth with enough force to level an entire city.

When it was initially discovered, space agencies gave this collision worryingly strong odds of one in 607.

However, with more careful observation that risk has now been considerably lowered.

Last year Richard Moissl, head of the ESA's planetary defence office, further reduced the odds of the asteroid hitting Earth from one in 784 to one in 1,584.

Moissi previously told MailOnline: 'It will go down now with every observation until it reaches zero in a couple of days at the latest. No one needs to be worried about this guy.'

The 165-foot (50 m) space rock was given a one in 560 chance of impact but experts say it is now almost certain to miss the Earth 

3. 1950 DA

For NASA to consider something a 'potentially hazardous object', it needs to be 460 feet (140 meters) in size with an orbit that brings it as close as within 4.6 million miles (7.5 million kilometres) of Earth's orbit around the Sun.

At 4,265ft (1.3km) in diameter and weighing 71 million tonnes, asteroid 1950 DA is over 90 times that size.

This makes 1950 DA the biggest asteroid that has a serious chance of colliding with our planet.

If it were to hit, the collision would release energy equivalent to detonating 75 billion tons of TNT - enough to trigger a global catastrophe like the one that wiped out the dinosaurs.

Currently, the asteroid is believed to have a one in 34,500 chance of hitting Earth on March 16, 2880.

In 2032, it will come within 6,959,357 miles (112,000,000 km) of Earth - a relatively close pass allowing for further observations.

NASA and ESA have already begun testing methods for pushing dangerous asteroids off course including slamming high-speed satellites into their surfaces.

Over the eight generations until 1950 DA reached Earth, a small disturbance could easily send it a safe distance from Earth.

A NASA spokesperson previously told MailOnline: 'If it is eventually decided 1950 DA needs to be diverted, the hundreds of years of warning could allow a method as simple as dusting the surface of the asteroid with chalk or charcoal, or perhaps white glass beads, or sending a solar sail spacecraft that ends by collapsing its reflective sail around the asteroid.

'These things would change the asteroid reflectivity and allow sunlight to do the work of pushing the asteroid out of the way.'

The asteroid 1950 DA has the potential to wipe out life on Earth. Based on its predicted orbit (pictured) the asteroid has a 1 in 34,500 chance of hitting Earth on March 16, 2880

4. 2023 TL4

Another asteroid which also has humanity-destroying potential is 2023 TL4.

After being spotted last year, scientists immediately recognised this huge asteroid as one of the biggest threats to Earth.

The space rock measures 1,083ft (0.33km) in diameter and is believed to weigh 43 million tonnes - more than 4,500 times the weight of the Eiffel Tower.

On collision, this could create a blast 150 times more powerful than that of the Tsar Bomba, the most powerful nuclear weapon ever detonated.

Current estimates suggest that there is a one in 181,000 chance of this asteroid colliding with Earth on October 10, 2119.

Just like 1950 DA, this should give space agencies enough time to push the asteroid off its course, should it appear to be on its way to Earth. 

The space rock 2023 TL4 measures 1,083ft (0.33km) in diameter and is believed to weigh 43 million tonnes - more than 4,500 times the weight of the Eiffel Tower. Its orbit (pictured) will bring it dangerously close to Earth in 2119

5. 2007 FT3 

While the odds of 2007 FT3 hitting Earth are low, it has the unwelcome distinction of being the asteroid with the chance of hitting Earth soonest.

If we get incredibly unlucky, this 2,165ft (0.34km) asteroid could hit Earth as soon as October 5th this year.

However, current observations of 2007 FT3's path give this only a one in 11.5 million chance of occurring.

The asteroid has slightly better odds of colliding with Earth on March 3, 2030, with a one in 10 million chance.

Although that may seem low, the odds of winning the Lotto jackpot are one in 45 million and many people still buy tickets each week. 

Since the odds are higher than zero, the object is still on ESA's risk list and is considered a potentially hazardous object. 

The asteroid 2007 FT3 could hit Earth as soon as October this year, however the odds are only one in 11.5 million 

6. 1979 XB

The final object with a chance of causing serious damage to Earth is an asteroid called 1979 XB.

At 2,165ft (0.34km) in diameter and weighing 49 million tonnes, should 1979 XB hit Earth, it would easily be capable of destroying an entire city.

First spotted in 1979, scientists believe that this asteroid currently has a one in 1.8 million chance of hitting Earth.

What makes 1979 XB scary is that it has essentially been 'lost' since its discovery.

No one has observed 1979 XB in 40 years and so its orbit is poorly understood.

What predictions we do have are based on the initial observations taken immediately after its discovery.

Given that Earth was just hit by a previously undetected asteroid, this might leave many feeling understandably anxious.

The asteroid 1979 XB is scarier than most since it has been 'lost' for 40 years. The predictions we have of its orbit (pictured) are only based on observations taken shortly after its discovery which makes its true danger a mystery 

How much danger are we really in?

Despite how scary these figures may seem, most scientists agree that the Earth is safe for now.

Dr Greg Brown, senior public astronomy officer at the Royal Observatory Greenwich, told MailOnline: 'As of today, there are no known asteroids that are both large enough to be of concern and have a sizeable chance to impact the Earth.'

If any asteroids do hit Earth it is likely that they will fall over the ocean or over the remote regions which still make up the majority of the planet's surface.

This renders the risk of any serious devastation from a meteoric impact extremely low.

However, that does not mean that the Earth is completely safe.

While the risk of a collision remains extremely low, scientists warn that some sort of dangerous encounter is inevitable in the very long run. This is why space agencies are investing in planetary defence systems (artist's impression)

While big impacts are very rare, Dr Brown points out that 'asteroid impacts are a case of when, not if.'

That is why space agencies around the world are investing huge funds into planetary defence projects.

These include ESA's DART mission which managed to knock an asteroid off course with kamikaze satellite in 2022.

Dr Brown adds: 'It is important that we continue to improve our ability to track these objects and work on measures to protect ourselves if they occur.'

{ https://www.dailymail.co.uk/ }

09-09-2024 om 17:23 geschreven door peter  

Boeing’s ruimtefiasco: astronauten achtergelaten in de ruimte door technische problemen

Key takeaways

De ambitieuze zoektocht van Boeing om een geloofwaardige speler te worden in de ruimtevaartindustrie kreeg een tegenslag toen de eerste astronautenmissie eindigde met twee achtergebleven astronauten in een baan om de aarde. De slecht functionerende capsule, Starliner, keerde leeg terug naar de aarde na een tumultueuze reis die werd geplaagd door defecte stuwraketten en lekken van het vitale gas helium.

Suni Williams en Butch Wilmore.

Beeld AFP

Technische problemen teisteren de missie

De missie begon veelbelovend, maar ontrafelde al snel onder het gewicht van de technische uitdagingen. Ondanks uitgebreide tests achtte Boeing de capsule veilig voor de terugreis, terwijl NASA een andere mening was toegedaan.

Uiteindelijk koos NASA voor een veiligere optie en boekte een vlucht met SpaceX, die hen pas in februari zal terugbrengen. Deze vertraging betekent dat de astronauten hun verblijf in de ruimte meer dan acht maanden zullen moeten verduren, meer dan twee keer de oorspronkelijke tijdspanne.

De terugreis wordt een beproeving

Het oorspronkelijke plan was dat de astronauten slechts een week na de lancering in de Starliner zouden terugkeren naar de aarde. Hun reis werd echter ontsierd door een cascade van problemen met de stuwraketten en heliumlekken. De ernst van deze problemen zette NASA ertoe aan om de risico’s te heroverwegen die gepaard gingen met het thuisbrengen van de astronauten in de onrustige capsule.

Astronauten gestrand in een baan om de aarde

Door de situatie zijn de twee astronauten gestrand in een baan om de aarde, in afwachting van een lift naar aarde. Hun lot hangt ervan af terwijl ingenieurs blijven worstelen met de mysteries van de slecht functionerende Starliner.

{https://www.msn.com/nl-be/ }

09-09-2024 om 16:34 geschreven door peter  

The “Shapiro time delay” near a positive mass reverses sign and turns into a “Shapiro time advance” near a negative mass. If the sender is moving sufficiently close to the speed of light, the Shapiro time advance would mean that a light signal can be reflected off a mirror and arrive back to the sender when the sender’s clock shows a time earlier than the original transmission time of the same signal.

Effectively, the Shapiro time advance is equivalent to communicating with a faster-than-light particle which violates causality. Within Einstein’s gravity, the technical term for a time machine of this type is a “closed timelike curve.”

Within the standard framework of Einstein’s gravity, a negative mass would allow children to prevent their parents from giving birth to them, a logical inconsistency. Time machines can also be created by traversable wormholes which, as Stephen Hawking recognized in a seminal paper about “chronology protection” from 1992, require negative energy as well.

“It has been suggested that an advanced civilization might have the technology to warp spacetime so that closed timelike curves would appear, allowing travel into the past,” the abstract of Hawking’s paper begins, and thereafter concludes by saying, “These results strongly support the chronology protection conjecture: The laws of physics do not allow the appearance of closed timelike curves.” Hawking’s conclusion was supported in a subsequent paper by Bernard Kay, Marek Radzikowski and Bob Wald, but the final verdict on its validity is awaiting a better understanding of quantum gravity.

If time machines are absent, what are the most extreme distortions of spacetime that our Universe is known to display?

In Einstein’s gravity, the Earth orbits the Sun because the Sun curves space. An analogy is offered by the surface of a trampoline which is curved by a bowling ball, causing a marble with the proper speed to move in a circle around the heavier ball. Removing the bowling ball would release the marble on a straight trajectory on the flat trampoline. Similarly, discarding the Sun would free Earth on a straight path toward interstellar space.

The spacetime curvature created by the Sun at our location is characterized by a length scale that is equal to the inverse of the square root of (GM/r^3c^2), where G is Newton’s constant, M is the mass of the Sun, r is the Earth-Sun separation, and c is the speed of light. Plugging in the relevant numbers yields a curvature length of 10,000 times the Earth-Sun separation. Another way to derive this number is by recognizing that the Earth’s speed around the Sun is 10,000 smaller than the speed of light, c.

Other astrophysical objects display a stronger spacetime curvature over a shorter length scale. The largest distortions of spacetime are expected near a black hole. Limiting our attention to the accessible region outside the event horizon, this curvature length scales in proportion to the black hole mass. The most massive black holes in the Universe have a mass of ten billion solar masses and a curvature scale of 1,000 times the Earth-Sun separation. The curvature length shrinks by billions of times for black holes or neutron stars formed from the collapse of massive stars.

What is the largest spacetime curvature that we observed so far in the Universe? It corresponds to a length scale of about 24 kilometers, the size of a large city on Earth, and is realized on the surface of neutron stars which carry about twice the mass of the Sun atnuclear density.

The same spacetime curvature characterizes an atomic nucleus because it has the same matter density as a neutron star. But a curvature length of 24 kilometers is 19 orders of magnitude larger than the size of an atomic nucleus and therefore has no significance when nuclei are smashed into each other in CERN’s Large Hadron Collider.

In conclusion, based on all we know from observations or theory within the standard model of physics, negative masses are forbidden for the same reason that time machines are not allowed. If aliens were able to create negative masses and use them for travel, then they would have also been able to travel back in time.

If time travel had been feasible, then future generations of quantum-gravity physicists could have been able to visit Earth and rewrite our history as they wish. For example, they could have killed Adolf Hitler and allowed six million Jews to thrive in Europe between 1939 and 1945. The fact that this never happened suggests that either time machines will never be constructed in our future or that their creators have no interest in saving human lives.

• Avi Loeb is the head of the Galileo Project, founding director of Harvard University’s – Black Hole Initiative, director of the Institute for Theory and Computation at the Harvard-Smithsonian Center for Astrophysics, and the former chair of the astronomydepartment at Harvard University (2011-2020). He is a former member of the President’s Council of Advisors on Science andTechnology and a former chair of the Board on Physics and Astronomy of the National Academies. He is the bestselling author of “Extraterrestrial: The First Sign of Intelligent Life Beyond Earth” and a co-author of the textbook “Life in the Cosmos”, both published in 2021. His new book, titled “Interstellar”, was published in August 2023.

{ https://thedebrief.org/category/space/ }

08-09-2024 om 23:18 geschreven door peter  

Planets and Water

To answer that question, the science team simulated how water behaves in the conditions present when planets are young. Many known exoplanets orbit close to their stars, which means they’re likely to be hot worlds. They probably have oceans of molten magma that haven’t yet solidified to make silicate bedrock mantles.

As it turns out water dissolves very well in these magma oceans. The iron core takes time to develop,” she said. “A large share of the iron is initially contained in the hot magma soup in the form of droplets,” she explained, noting that water sequestered in this soup combines with the iron droplets and sinks with them to the core. “The iron droplets behave like a lift that is conveyed downwards by the water,” Dorn said.

That kind of mixing of iron and water happened in the moderate pressure environment in Earth’s interior. Larger planets with higher interior pressures presented a challenge to understand. It turns out they mix water and iron, too. “The larger the planet and the greater its mass, the more the water tends to go with the iron droplets and become integrated in the core,” said Dorn. “Under certain circumstances, iron can absorb up to 70 times more water than silicates. However, owing to the enormous pressure at the core, the water no longer takes the form of H₂O molecules but is present in hydrogen and oxygen.”

Evolving Planets over Time

This result is a big deal if you want to understand how planets form and develop. That’s because the water never escapes the planet’s core. However, under the right conditions, water mixed in with the magma ocean can “de-gas” under the right conditions. Essentially, it separates and rises to the surface as the magma cools and forms the mantle. “So if we find water in a planet’s atmosphere, there is probably a great deal more in its interior,” explained Dorn.

That gives a lot of new information to use as scientists search for planets around other stars and look for habitable worlds. In particular, astronomers using the JWST can track the types of molecules in exoplanet atmospheres and use that information to find habitable worlds. “Only the composition of the upper atmosphere of exoplanets can be measured directly,” said Dorn. “Our group wishes to make the connection from the atmosphere to the inner depths of celestial bodies.”

Currently, the team studies exoplanet TOI-270d. “Evidence has been collected there of the actual existence of such interactions between the magma ocean in its interior and the atmosphere,” said Dorn. It’s at the top of her list of interesting objects to examine more closely for water, along with another one called K2-18b. It seems to be a promising candidate for habitability as well.

So, Does Deep Water Imply Life or Habitability?

Since water is important in the search for life-bearing worlds, looking for wet Earth-type and super-Earth worlds is the next step in searching out life. Dorn’s team found that planets with these deep water layers are likely to be fairly rare. That’s because most of their water is not on the surface. In other words, they may not be ocean worlds, but places with water trapped in their cores.

That’s not all bad. The science team assumes that even planets with a relatively high water content could have the potential to develop Earth-like habitable conditions. Dorn’s team may give scientists new ways to look for water-abundant worlds.

For More Information

• Planets Contain More Water Than Thought
• The Interior as the Dominant Water Reservoir in Super-Earths and Sub-Neptunes

{ https://www.universetoday.com/ }

08-09-2024 om 01:40 geschreven door peter  

Exogenesis

As indicated in their paper, impacts from asteroids, comets, and large meteors are more often associated with destruction and extinction-level events. However, multiple lines of evidence indicate that these same types of impacts may have supported the emergence of life on Earth roughly 4 billion years ago. These events not only delivered volatiles (such as water, ammonia, and methane) and organic molecules, but modern research indicates that they also created new substrates and compounds essential to life.

Moreover, they created a variety of environments that were essential to the emergence and sustainment of life on Earth. As they wrote:

“Exogenously delivered materials have been estimated to be an important source of organics on early Earth. Shockwaves could provide the energy for organic synthesis of important precursors like HCN or amino acids. The iron and heat from very large impactors can facilitate the reducing atmospheric conditions necessary for abundant HCN production. Impacts fracture and, in typical terrestrial events, melt the target: the more permeable substrates and excavation of deeper rock layers promote hydrothermal activity and endolithic habitats.”

According to the latest fossilized evidence, the earliest life forms emerged on Earth roughly 4.28 billion years ago. These fossils were recovered from hydrothermal vent precipitates in the Nuvvuagittuq Greenstone Belt in northern Quebec, Canada, confirming that hydrothermal activity played a vital role in the emergence of life on Earth. But what about the many “Ocean Worlds” that reside in the outer Solar System? This includes bodies like Europa, Ganymede, Enceladus, and Titan, as well as Uranus’ moons Ariel and Titania, Neptune’s moon Triton, and Trans-Neptunian bodies like Pluto, Charon, and possibly more.

Ocean Worlds

This term refers to bodies predominantly composed of volatile elements such as water and differentiated between an icy crust and a rocky and metallic core. At the core-mantle boundary, tidal flexing (the result of gravitational interaction with another body) causes a buildup of heat and energy released via hydrothermal vents into the ice. This allows these worlds to maintain oceans of liquid water in their interiors. In short, these worlds have all the necessary ingredients for life: water, the requisite chemical compounds, and energy.

Furthermore, data from the NASA/ESA Cassini–Huygens mission confirmed that the plumes regularly erupting from Enceladus’ southern polar region contain organic molecules. Last but not least, the presence of surface craters indicates that these bodies have experienced surface impacts throughout their history. The question naturally arises: could impacts have delivered the necessary building blocks of life to “Ocean Worlds” the same way they delivered them to the inner Solar System? And if so, what does that mean about their potential habitability today? As the team wrote in their paper:

“Impact processes are likely an important part of the answers to these questions, as impacts can drive exchange through the ice crust—either through direct seeding or flushing through the crust—and therefore drive episodic influxes of organic and inorganic materials from the surface and/or from the impactor itself. Impacts can also generate ephemeral microcosms: any liquid water melted during impact freezes out over timescales commensurate with the impact energy.”

“The exciting potential for chemistry within these pockets has been established, from concentrating salts to driving amino acid synthesis. Furthermore, shock-driven chemistry of icy, sometimes organic-rich (in the case of Titan especially) target materials may generate new “seed” compounds (e.g., amino acids or nucleotides) in the melt pool.”

Investigation

The first step for MacKenzie and her team was to investigate the initial shock levels created by the most common impacts for Ocean Worlds—comets that likely originated from the Kuiper Belt and Oort Cloud. To do this, the team calculated the velocities and maximum pressure that would be achieved by impacts involving icy and rocky bodies. They also considered how this would vary based on different families (primary or secondary impacts) and which systems were involved – i.e., Jupiter or Saturn. Whereas primary impacts involve comets or asteroids, secondary impacts are caused by the ejecta they create.

In the case of the Jupiter and Saturn systems, secondary impactors may be icy or rocky depending on where they originated (an icy body like Europa, Enceladus, and Titan, a rocky body like Io and larger asteroids). Whereas primary impacts have higher velocities and produce larger melt volumes), secondary impacts are more frequent. To determine melt sizes, the team consulted observed crater sizes on Europa, Enceladus, and Titan, and dynamic models that calculate the cumulative rate of cratering over time. They then compared the peak pressures at impact to thresholds for the survivability of elements essential to life, organic molecules, amino acids, and even microbes identified in previous studies.

From this, they determined that most impacts at Europa and Enceladus experience peak pressures greater than what bacterial spores can survive. However, they also determined that a significant amount of material still survives these impacts and that higher first-contact pressures could also facilitate the synthesis of organic compounds in the meltwater that fills the craters. Meanwhile, on average, Titan and Enceladus experienced impacts with lower impact velocities, creating peak pressures that fall within the tolerance range for both bacterial spores and amino acids.

The next step was to consider how long fresh craters would survive and whether this would be sufficient for synthesizing biological materials. Based on the observed crater sizes on Enceladus and Europa, they determined that the longest-lived craters last only a few hundred years, whereas Titan could take centuries to tens of thousands of years for fresh craters to freeze. While Europa and Enceladus experience more high-velocity impacts (due to Titan’s dense atmosphere), the long-lived nature of Titan’s craters means that all three bodies have a chance for organic chemistry experiments to occur.

They also considered resurfacing rates on Europa, Enceladus, and Titan and how these would cycle biological material to their interiors. In all three cases, the satellites have relatively “young” terrain, implying regular resurfacing events.

Results

Based on these considerations, Mackenzie and her team determined that melts produced by comet impacts on Europa, Enceladus, and Titan have been frequent and long-lived enough to be of astrobiological interest. However, this varies based on the composition of the comets and the surface ice in question. As they summarized:

“At Europa and Enceladus, the survival and deposition of impactor organics is more important as there are fewer surface organics within the ice crust to seed the melt pool. On Titan, the survival of elements like phosphorous may be more important. Thus, even the small, more frequent impact events contribute to the astrobiological potential by delivering less modified compounds to the surface that are available either for immediate reaction if melt is produced or for future processing (including in subsequent impact events).”

For instance, they found that a comet impacting Europa at the average impact velocity would create a 15 km (9.3 mi) crater and provide ~1 km³ (0.24 mi3)of meltwater. Based on the abundance of glycine (an essential amino acid) found on the comet 67P Churyumov–Gerasimenko, they determined that several parts per million would survive – roughly three orders of magnitude higher than what has been observed forming around hydrothermal vents here on Earth. “Thus, impactors seed whatever chemistry happens in the melt, providing organic and other essential elements depending on the impactor composition,” they added.

While this does not necessarily mean that these and other “Ocean Worlds” are currently habitable or actively support life, they demonstrate potential for future study. In the coming years, missions like the ESA’s JUpiter ICy moons Explorer (JUICE), and NASA’s Europa Clipper and Dragonfly missions will reach Ganymede, Europa, and Titan (respectively). There are also plans to create an Enceladus Orbiter to pick up where the Cassini-Huygens probe left off by examining Enceladus’ plume activity more closely.

Therefore, conducting in-situ sampling and analysis on these moons could provide powerful insight into prebiotic chemical pathways and determine under what conditions life can emerge. These sample studies will also address the larger question of whether or not life could exist in the interiors of “Ocean Worlds,” providing a preview of what future missions prepared to explore beneath the ice will find.

Further Reading: 

• The Planetary Science Journal

{ https://www.universetoday.com/ }

08-09-2024 om 01:32 geschreven door peter  

Study: There Were Volcanic Eruptions on Moon as Recently as 123 Million Years Ago

There is extensive geologic evidence of ancient volcanic activity on the Moon, but it is unclear how long that volcanism persisted. Magma fountains produce volcanic glasses, which have previously been found in samples of the Moon’s surface. Dr. Qiuli Li and colleagues from the Institute of Geology and Geophysics at the Chinese Academy of Sciences have analyzed around 3,000 glass beads from lunar soil samples collected by China’s Chang’e-5 mission. They’ve identified three glass beads as having a volcanic origin on the basis of their textures, chemical compositions, and sulfur isotopes. Uranium-lead dating of these volcanic beads shows that they formed approximately 123 million years ago.

Volcanic eruption producing glass beads on the Moon.

Image credit: T. Zhang & Y. Wang.

Samples collected by the Apollo, Luna and Chang’e‑5 missions have previously shown there was widespread basaltic volcanism on the Moon extending from about 4.4 to 2 billion years ago.

The findings of the current study demonstrate that volcanism persisted much longer than was previously suspected, at least on smaller, more localized scale

“Dating of lunar volcanic basalt samples returned to Earth by the Apollo and Luna missions or delivered to Earth as lunar meteorites has shown that lunar basaltic volcanism continued until at least 2.9-2.8 billion years ago,” the researchers said.

“However, analysis of lunar samples returned by the Chang’e-5 mission has demonstrated that basaltic volcanism persisted until at least 2 billion years ago.”

“Remote sensing observations have indicated potentially even younger volcanism during the late Copernican era (less than 800 million years ago) on the Moon.”

“However, none of these remote observations provide a precise date for the potential volcanism.”

“In addition, the proposed extrusions of late-Copernican mare basalt cover only restricted areas, no samples of which are available.”

“Eruptions of gas-rich magma can generate magma fountains, which produce submillimeter glass beads.”

“Such beads could potentially be deposited over wide areas and subsequently be transported further across the lunar surface by impact.”

“The volcanic glasses could be a trace component in existing samples.”

In their study, Dr. Li and co-authors sorted through 3,000 tiny glass beads they recovered from a lunar sample collected by Chang’e‑5, examining the bead’s chemical compositions, physical textures and sulfur isotopes to distinguish potential volcanic glasses from glasses produced by meteorite impacts.

They identified three beads as being of volcanic origin, then used radiometric dating to determine the beads formed 123 million years ago.

The volcanic beads contain high abundances of potassium, phosphorus and rare-earth elements, known as KREEP elements, which can produce radioactive heating.

Localized heating due to KREEP elements might melt rocks in the Moon’s mantle, leading to small amounts of magma erupting to the surface.

“We measured high abundances of rare earth elements and thorium in the volcanic glass beads, which could indicate that such recent volcanism was related to local enrichment of heat-generating elements in the mantle sources of the magma,” the researchers said.

• Their paper appears in the journal Science.
• Bi-Wen Wang et al. 2024. Returned samples indicate volcanism on the Moon 120 million years ago. Science 385 (6713); doi: 1077-1080; doi: 10.1126/science.adk6635

{ https://www.sci.news/ }

07-09-2024 om 21:23 geschreven door peter  

De Boeing-ruimtecapsule Starliner is zaterdag geland op aarde. Dat blijkt uit beelden die NASA heeft vrijgegeven. De capsule landde zonder de astronauten die het naar het internationale ruimtestation ISS heeft gebracht, nadat NASA had besloten dat het risico te groot was.

De Starliner landde zaterdag zachtjes op de White Sands ruimtebasis in New Mexico rond 06.01 uur. De landing werd vertraagd door parachutes en airbags.

De capsule had ongeveer zes uur eerder het ISS verlaten, zonder de twee astronauten die op de heenvlucht naar het ISS meereisden. Astronauten Sunita Williams en Butch Wilmore zijn al sinds 6 juni aan boord van het ISS. Ze voerden een testmissie uit die ongeveer een week had moeten duren. Maar door problemen met de Starliner konden ze niet terugkeren. Er werd gevreesd dat het toestel niet over de nodige stuwkracht zou beschikken om de baan rond de aarde te verlaten.

Williams en Wilmore kwamen aan op 6 juni

© Foto: NASA

De Starliner werd 3 maanden geleden voor het eerst met 2 Amerikaanse astronauten aan boord gelanceerd: Sunita Williams (58) en Butch Wilmore (61). Tijdens hun vlucht naar het Internationaal ruimtestation ISS waren er al technische problemen. 

Williams en Wilmore kwamen op 6 juni aan in het internationaal ruimtestation ISS. Het was de bedoeling dat ze er 8 dagen zouden blijven, maar een resem technische defecten besliste daar dus anders over. Zo was er een probleem met de stuwmotoren, maar er werden ook 3 heliumlekken ontdekt.

Door die problemen moest de automatische piloot tijdens de heenvlucht uitgeschakeld worden, en moesten de astronauten de capsule handmatig koppelen aan het ISS. Nadat een eerste poging mislukte, slaagden ze daar bij een tweede poging toch in.

Vrees voor gebrek aan stuwkracht onterecht

Omdat de technische problemen nog altijd niet helemaal opgelost zijn, is de Starliner nu dus onbemand teruggekeerd naar de aarde. Er werd gevreesd dat het toestel niet over de nodige stuwkracht zou beschikken om de baan rond de aarde te verlaten. 

Ruimtecapsule Starliner succesvol geland op aarde

De Starliner landde vanochtend rond 6.01 uur (onze tijd) zachtjes op de White Sands-ruimtebasis in New Mexico. De landing werd vertraagd door parachutes en airbags.

De capsule had ongeveer 6 uur eerder het ISS verlaten, zonder de 2 astronauten dus die op de heenvlucht naar het ISS meereisden. 

Een vlotte terugvlucht was belangrijk voor fabrikant Boeing, niet alleen voor het vertrouwen, maar ook voor toekomstige kansen om nieuwe goedkeuringen voor bemande vluchten te krijgen.

Williams en Wilmore keren pas in februari terug

Williams en Wilmore zullen in februari volgend jaar terugkeren naar de aarde met de Crew 9-missie van SpaceX, de grote concurrent van Boeing. Ze zullen dan 9 maanden doorgebracht hebben in de ruimte in plaats van de voorziene week. 

Volgens NASA gaat het momenteel goed met het duo en hebben ze regelmatig contact met hun familie. 

NASA heeft nu beslist om de twee astronauten met een ruimtevaartuig van SpaceX weer naar huis te brengen. De Crew 9-missie van SpaceX zal daarom later in september met slechts twee van de vier voorziene astronauten naar het ISS vertrekken. Bij de terugkeer naar aarde in februari volgend jaar, zullen Wilmore en Williams de twee vrijgekomen plaatsen innemen.

{ https://www.msn.com/nl-be/ }

07-09-2024 om 20:47 geschreven door peter  

ScreenThe frost on Olympus Mons, is shaded in blue.

CREDIT: Credit: ESA/DLR/FU Berlishot

According to the team’s analysis, the layer of water frost appears each morning until the rising sun heats up the planet’s surface and causes it to evaporate back into the atmosphere. The process normally only takes a few hours, as the frost only appears as a very thin layer, likely only one-hundredth of a millimeter thick, before disappearing. For comparison, this is about the thickness of a human hair.

Still, the researchers say that the actual covering of frost is incredibly vast. In fact, the team calculates that as much as 150,000 tons of water are evaporated and then redeposited on the Martian surface every single day. “That’s roughly the equivalent of 60 Olympic-sized swimming pools,” they explain.

Discovery Atop Martian VOlcanoes is the Culmination of Six Year Long Project

In the team’s published study, which appears in the journal Nature Geoscience, Valantis notes how he first began searching for evidence of frost atop Martian volcanoes back in 2018 when he was still a Ph.D. student at the University of Bern. That effort involved combing through thousands of high-resolution photos of Mars captured by the Color and Stereo Surface Imaging System (CaSSIS) instrument onboard the European Space Agency’s Trace Gas Orbiter.

When an image revealed a spectral signature consistent with water frost, Valantis says he placed it into a larger series of images sorted by time, location, and season. As more images joined the series, Valantis found that they began to reveal a daily cycle, where this ultra-thin layer of water frost was deposited overnight and then evaporated back into the atmosphere by the rising sun each morning.

“What we’re seeing may be a remnant of an ancient climate cycle on modern Mars,” Valantis posited, “where you had precipitation and maybe even snowfall on these volcanoes in the past.”

To ensure that what they were seeing was real since it was so unexpected, Valantis and his colleagues verified the images using separate observations made by the High-Resolution Stereo Camera onboard the ESA’s Mars Express orbiter and the Nadir and Occultation for Mars Discovery spectrometer onboard the Trace Gas Orbiter. All told, the researchers say over 30,000 images were selected and verified during the six-year project.

In the study’s conclusion, the team says they believe the water frost, which sits inside the caldera of several Martian volcanoes within the Tharsis range, is created and deposited due to microclimates that form within these massive structures. These microclimates exist due to the enormous height of the Tharis volcanoes. According to the researchers, the mountainous volcanoes of Tharsis range between one and two times the size of Mount Everest on Earth. The largest, Olympus Mons, is as wide as France.

Astrobiology and the Search for Marian Life

Since his transition from Bern University to Brown University, Valantis says he is going to continue exploring “Martian mysteries.” This includes transitioning to a full-time astrobiology role, where he will apply his analysis skills to help characterize the ancient environments around Martian vents, where microbial life may have once thrived.

According to the press release announcing the discovery, the researchers believe that modeling how the frosts are forming atop these Martian volcanoes “could allow scientists to reveal more of Mars’ remaining secrets, including understanding where water exists and how it moves, as well as understanding the planet’s complex atmospheric dynamics, which is essential for future exploration and the search for possible signs of life.”

If everything goes well, Valantis said he hopes his work, including his discovery of water frost atop Martian volcanoes, can help lead to the detection and collection of high-value Martian soil samples that are brought back to Earth for study. In fact, he says that searching for life that evolved outside of Earth has always captured his imagination, so he is not going to miss out on the opportunity to help science try to make another major discovery.

“This notion of a second genesis, of life beyond Earth, has always fascinated me,” Valantinas said.

• Christopher Plain is a Science Fiction and Fantasy novelist and Head Science Writer at The Debrief. Follow and connect with him on X, learn about his books at plainfiction.com, or email him directly at christopher@thedebrief.org.

Inside Monster Martian Volcanoes

The newly discovered volcano has monstered-sized company in the form of three other gigantic Martian volcanoes

Background image: NASA Mars Global Surveyor (MGS) Mars Orbiter Laser Altimeter (MOLA) digital elevation model. Geologic interpretation & annotations by Pascal Lee and Sourabh Shubham 2024

The volcano, temporarily named the Noctis, spans 280 miles wide and was discovered alongside a buried ice glacier to the east of Mars.

NASA/USGS

“This area of Mars is known to have a wide variety of hydrated minerals spanning a long stretch of Martian history,” said Sourabh Shubham, a graduate student at the University of Maryland’s Department of Geology.

{ https://thedebrief.org/category/space/ }

05-09-2024 om 22:33 geschreven door peter  

In recent years, astronomers have identified several enigmatic objects emitting repeating radio signals. In 2020, GLEAM-X J162759.5-523504.3, located near the galactic center, was observed emitting unusually bright flashes for just three months before falling silent.

Another object, discovered last year, GPM J1839-10, behaves like a slow pulsar, emitting five-minute radio bursts every 22 minutes. 

However, the newly-discovered radio signal acts a bit differently.

The signal was first detected during routine observations by the ASKAP radio telescope, located in Australia’s Wajarri Yamaji Country. The telescope, known for its wide field of view, was monitoring a gamma-ray burst when it stumbled upon ASKAP J1935+2148. The signal stood out due to its unique properties, including its long period and distinct emission states. 

Dr. Manisha Caleb, an astrophysicist at the University of Sydney and the lead author of the study, said in a press release that she thinks this could be a new type of neutron star.

“It is highly unusual to discover a neutron star candidate emitting radio pulsations in this way,” she said in a press release. “The fact that the signal is repeating at such a leisurely pace is extraordinary.”

Following the initial detection, the team conducted further observations for several months using both ASKAP and the more sensitive MeerKAT radio telescope in South Africa. 

Equipped with a special type of radio receiver, the ASKAP telescope was set up in a grid pattern to scan the sky at a frequency of 887.5 MHz. The signals it picked up were divided into smaller chunks to get a clearer picture, and the data was processed every 10 seconds to catch the bright pulses from ASKAP J1935+2148. Meanwhile, the MeerKAT telescope, which operates at a higher frequency range (0.86-1.71 GHz), provided more detailed and sensitive observations. 

“What is intriguing is how this object displays three distinct emission states, each with properties entirely dissimilar from the others,” Caleb explained. “The MeerKAT radio telescope in South Africa played a crucial role in distinguishing between these states. If the signals didn’t arise from the same point in the sky, we would not have believed it to be the same object producing these different signals.”

According to the study, the astronomers observed bright linear pulses that lasted anywhere between 10 and 50 seconds, followed by weaker pulses that followed a circular pattern that only lasted 370 milliseconds, followed by a lull where no pulses were detectable. This would all then repeat. 

This new mysterious radio signal challenges the current astrophysical models of neutron stars and white dwarfs. Neutron stars, known for their rapid rotation, typically complete rotations in seconds or fractions of a second. The 53.8-minute period of ASKAP J1935+2148 places it in the “pulsar death valley,” where detectable radio signals are not expected. In other words, if this is a neutron star, it shouldn’t be giving off anything.

One hypothesis is that ASKAP J1935+2148 could be an ultra-long period magnetar, a type of highly magnetized neutron star. However, the slow rotation and continued radio emission are unusual for such objects. Another possibility is a highly magnetized white dwarf, but no known white dwarfs have been observed to emit radio waves in this manner, making this explanation less likely.

Caleb and her team currently believe that this radio signal is probably from a slow-spinning neutron star or a binary system with a neutron star or another white dwarf. They admit that this is only a hypothesis since something like this has never been observed before, and further research needs to be done.

“It might even prompt us to reconsider our decades-old understanding of neutron stars or white dwarfs,” Caleb concluded. “How they emit radio waves and what their populations are like in our Milky Way galaxy.”

• MJ Banias covers space, security, and technology with The Debrief. You can email him at mj@thedebrief.org or follow him on Twitter @mjbanias.

{ https://thedebrief.org/category/space/ }

05-09-2024 om 21:16 geschreven door peter  

 By Chris Eberhart Fox News

US Secretary of Energy Jennifer Granholm (Photo: AP)

It's a drone; it's a UFO; it's really who you ask: What's buzzing around U.S. nuclear sites?

Going back from the 1940s and ‘50s to the present day, whistleblowers have reported UFO sightings around nuclear sites, but Department of Energy (DOE) Secretary Jennifer Granholm said they’re "drones." 

Rep. Anna Paulina Luna, R-Fla., hit Granholm with rapid-fire questions, including if the DOE was reverse engineering crashed alien technology, and if it worked with a counter-terrorism task force. 

Granholm's answers were, "I have no knowledge of that," and "Yes," respectively, which an expert told Fox News Digital is a "big deal" admission.

• UFO SIGHTING ‘HOTSPOTS’ SHOW CLUSTERS AROUND NUCLEAR ACTIVITY AND WAR ZONES

A Fox News Digital-created UFO hotspot map based off information by the Department of Defense. 

(Julia Bonavita/Fox News Digital based on AARO's Data)

The fiery exchange between Luna and Granholm was about five minutes of a 2.5-hour Congressional Oversight Committee hearing on May 23. 

Luna's last question, "Does the DOE work with JSOC (Joint Special Operations Command)?" raised eyebrows and created buzz on social media.

• RUSSIAN UFO ENGAGEMENTS, SECRET ‘TIC TAC’ REPORT AND 3 KEY FIGURES SLIP UNDER RADAR AT CONGRESSIONAL HEARING

Granholm danced around the question at first, but Luna repeated the inquiry and demanded a yes or no answer. 

Granholm finally responded, "Yes, we do." 

Investigative journalist and leading UFO expert Jeremy Corbell said, "This was a bold move by Congress." 

WATCH FULL EXCHANGE BETWEEN LUNA AND GRANHOLM

JSOC is a military task force that plans and executes special operations missions under the command of U.S. Special Operations Command.

Corbell said a whistleblower had pointed out that JSOC had worked with the DOE to recover crashed alien spacecraft and reverse-engineer their technology.

• This technology could turn us into charcoal

“JSOC is likely heavily involved in the aircraft recovery program under the purview of the CIA, so it’s a big deal for the Department of Energy to acknowledge that it’s working with JSOC,” Corbell told Fox News Digital. “Secretary Granholm has been loath to acknowledge that.”

JSOC has denied these allegations and implications in previous statements. Fox News Digital reached out to JSOC for comment but did not receive a response.

Rep. Anna Paulina Luna questioned Energy Secretary Jennifer Granholm about reverse engineering alien technology. 

(Fox News Digital/John Michael Raasch)

In an email to Fox News Digital, Luna said that while “some people, like Secretary Granholm, want to ridicule these things,” “more than 50 percent of Americans believe UAPs may exist.”

“That means the federal government should be taking this seriously,” the Florida Republican said. “I have confronted Energy Secretary Granholm directly with multiple reports and statements from the Department of Defense, and she continues to deny the facts.”

“And that’s why I think the American people have lost faith in government transparency.”

• UFOs aren’t just in the air, they’re in the water too, posing a threat to maritime safety, says former naval officer

Luna’s exchange with Granholm wasn’t the end of her interactions with the DOE.

She submitted nine questions to the DOE, obtained exclusively by Fox News Digital. The questions include:

“DOE has received the QFR and will respond directly to the committee and members of Congress,” a DOE spokesperson said in an email.

Footage of a UFO flying near the USS Omaha off the coast of San Diego in July 2019 and disappearing into the ocean without a splash or crash debris. 

(Jeremy Corbell/Weaponized Podcast)

Former Navy pilot Ryan Graves, former Navy commander David Fravor, and former U.S. intelligence officer David Grush testified before a House subcommittee specializing in UFOs. 

(House of Representatives Subcommittee on National Security, Borders, and Foreign Affairs)

Luna’s Question

1. How are Unmanned Aerial Vehicles (UAVs) and Unmanned Aerial Systems (UAS) designated by DOE?
2. What characteristics must an object have to be considered a UAP?
3. How many UAP intrusions have been reported to the All-Domain Anomaly Resolution Office (AARO)?
4. F1 events deploy private companies that can disable drones and track the pilots. Is that technology available to DOE? Follow-up: If so, how many drones were able to track the pilots? And how many were able to be disabled?
5. Follow-up: If so, how many drones were you able to track to their operators? And how many were you able to disable?
6. This year alone, how many UAP intrusions have been reported internally at all critical infrastructure locations under DOE’s oversight (e.g., nuclear weapons, refining, and deployment sites such as Pantex and the Savannah River Site)?
7. There have been multiple reports of frequent drone intrusions over DOE nuclear facilities, including the incident that occurred at Lawrence Livermore National Laboratory (LLNL) on April 1, 2021. Can you tell us more about DOE’s current security measures to prevent unauthorized drone activity? Also, given the frequency of these incidents, what steps are being taken to strengthen these measures?
8. A recent AARO report emphasized that better data collection is essential to understanding the UAP phenomenon. What technologies and methodologies is DOE employing to collect and analyze data related to UAP sightings, especially near critical infrastructure?
9. Given the potential security and safety risks posed by UAPs near nuclear facilities, what protocols are in place to ensure the safety of DOE personnel and the public? Have there been any documented cases of personnel being adversely affected as a result of an encounter with a UAP?
10. In the spirit of transparency, how is the Department of Energy handling public disclosure of UAP incidents? Are there plans to declassify and release more detailed reports on UAP sightings over Department of Energy facilities to keep the public informed and reassured?

• Crime scene reconstruction experts say they see at least two aliens “trying to scare off troublesome humans.”

Watch Rep. Tim Burchett interview: “There’s a cover-up”

WATCH INTERVIEW WITH REP. TIM BURCHETT: "THERE'S A COVER-UP"

Video

Department of Energy: Sightings are ‘drones’, not UFOs

Before Luna’s exchange with Granholm, Republican Rep. Tim Burchett of Tennessee questioned the Energy secretary about “suspicious sightings” of UFOs near nuclear facilities.

The question seemed to catch Granholm off guard.

• Pentagon UFO report says aliens don’t exist: ‘If America doesn’t come clean, other countries will’

She responded that the Department of Defense had concluded that there was no evidence of UFOs or aliens.

“But there is the possibility of malicious drones out there,” Granholm said, emphasizing that safety and defensive measures are in place.

As both senators pointed out, UFO sightings near nuclear facilities predate drones.

This was one of several examples of unexplained UAPs listed in NASA’s Sept. 14 report. 

(NASA)

In 2018, a mysterious jellyfish-like object was spotted flying over a military base in Iraq. 

(Jeremy Corbell/Weaponized Podcast)

Recently declassified documents about a UFO program called Kona Blue detail a government plan to collect and reverse engineer crashed alien technology.

“Several highly sensitive and unconventional aerospace discoveries have been identified and significant progress has been made,” former U.S. Senator Harry Reid said in a June 2009 letter.

An excerpt from a 2009 letter from former U.S. Senator Harry Reid discussing the need to keep the government’s crashed

alien technology recovery program and reverse engineering efforts secret. (Department of Defense)

• Alien video shows ‘beings’ using ‘cloaking’ device: ‘submit this for peer review’

“Given the current rate of success, continued research into these subjects is likely to lead to technological advances requiring special protection in the near future…”

“Given the potential applications of these technologies in future systems, including space flight, weapons, communications and propulsion, standard management and protection procedures cannot adequately ensure that all aspects of the project will be adequately protected.”

READ THE FULL DECLASSIFIED KONA BLUE REPORT

AARO, The Pentagon’s specialist unit investigating UAP said “multiple” whistleblowers mentioned Kona Blue during its investigation into the alleged aircraft recovery program.

In its report, AARO stated: History and origins Kona Blue said it was “proposed” to Homeland Security leadership but “never approved or formally enacted.”

According to AARO, the project has never received any materials or funding, and the Department of Homeland Security disapproved the project in 2011 “citing concerns about the adequacy of the program’s legitimacy” and ordered it immediately halted.

According to AARO, its complete origins and history can be found at: It is here.

{ https://www.foxnews.com/ }

05-09-2024 om 00:53 geschreven door peter  

04-09-2024 om 23:29 geschreven door peter  

NASA has an explanation for the “strange noise” emitted by Boeing Co.’s Starliner spacecraft docked at the International Space Station. 

The noise was heard by astronaut Butch Wilmore, who radioed mission control about the sound Saturday, as first reported by Ars Technica. “There’s a strange noise coming through the speaker [on Starliner],” he said. “I don’t know what’s making it … I don’t know if there’s something that’s maybe connected between here and there making that happen,” he added.

NASA said the noise — which is no longer being emitted — was the result of an audio configuration between the Boeing capsule and the International Space Station. Boeing referred MarketWatch to NASA for comment.

Related:

•  NASA astronauts to return to earth with Elon Musk’s SpaceX, Boeing Starliner to come back empty

• https://youtu.be/FOd1ceFuzpQ

• https://youtu.be/Hnz-jsbUkLc?list=TLPQMDQwOTIwMjS2chNflp3Ogw

“A pulsing sound from a speaker in Boeing’s Starliner spacecraft heard by NASA astronaut Butch Wilmore aboard the International Space Station has stopped. The feedback from the speaker was the result of an audio configuration between the space station and Starliner,” NASA’s Commercial Crew program wrote Monday on X, formerly Twitter. “The space station audio system is complex, allowing multiple spacecraft and modules to be interconnected, and it is common to experience noise and feedback.”

“The crew is asked to contact mission control when they hear sounds originating in the comm system,” the Commercial Crew program added. “The speaker feedback Wilmore reported has no technical impact to the crew, Starliner, or station operations, including Starliner’s uncrewed undocking from the station no earlier than Friday, Sept. 6.”

Starliner will return to Earth uncrewed with Wilmore and his fellow crewmember Suni Williams returning in a SpaceX capsule after the Boeing capsule was beset with problems. The Boeing spacecraft is scheduled to autonomously undock from the space station at approximately 6:04 p.m. Eastern time on Sept. 6 to begin the journey home, weather conditions permitting, NASA said, in an Aug. 30 statement. NASA and Boeing are targeting approximately 12:03 a.m. on Sept. 7 for the landing and conclusion of the flight test at White Sands Space Harbor in New Mexico.

Also read: 

• Boeing Starliner saga: Do NASA astronauts get overtime pay in space?

NASA and Boeing have wrestled with helium leaks and thruster issues on Starliner, which launched on June 5 and arrived at the ISS the following day. The capsule was initially expected to be docked at the orbiting space lab for at least eight days before bringing the two astronauts home. They have now been there for more than 80 days.

The test, which has faced a number of delays in recent years, is the first crewed mission of the Starliner capsule. The spacecraft’s launch in June also marked the first time NASA has had three crewed vehicles in orbit.

SpaceX’s Crew-9 mission is scheduled to depart for the ISS no earlier than Sept. 24.

Related: 

• Boeing has recorded $1.5 billion of Starliner forward losses, says Jefferies

Boeing shares were down 8% at 11:09 a.m. Eastern time Monday, amid a Wells Fargo downgrade, outpacing the S&P 500 index’s decline of 1.4%.

{ https://www.msn.com/en-us/ }

04-09-2024 om 22:43 geschreven door peter  

Een ster ontdekt, die uit de Melkweg zou kunnen “ontsnappen”: hij raast door de ruimte met ruim 1,6 miljoen kilometer per uur

door Janine

W. M. Keck Observatory/Adam Makarenko

Gewoonlijk draaien sterren rond het centrum van een sterrenstelsel, bijvoorbeeld de Melkweg: dit is het geval voor de zon en de meer dan 200 miljard sterren in ons sterrenstelsel... op één na. Sommige wetenschappers hebben een object gezien dat zo groot en zwaar is als een ster en dat zich met meer dan 1,6 miljoen kilometer per uur voortbeweegt, een snelheid die zo hoog is dat het aan de zwaartekracht van de Melkweg ontsnapt... vroeg of laat. Laten we eens kijken hoe dit mogelijk is!

Er is een ster ontdekt die op de vlucht is uit de Melkweg

We bevinden ons in het project Backyard Worlds: Planet 9, dat tot taak heeft nieuwe planeten en bruine dwergen in de omgeving van ons zonnestelsel te ontdekken, ook met de hulp van amateurs. Door de beelden te bestuderen die zijn gemaakt door de Wide Field Infrared Explorer of WISE-missie en latere missies, hebben sommige amateurwetenschappers een nooit eerder gezien object gezien, een hemellichaam dat veel te snel door de ruimte beweegt, alsof het ontsnapt uit de Melkweg. Dit zijn de woorden van een van de ontdekkers, die samen met anderen een studie publiceerde in Astrophysical Journal Letters:

Ik kan het niveau van opwinding niet beschrijven. Toen ik voor het eerst zag hoe snel het bewoog, was ik ervan overtuigd dat het al was gemeld.

Het hemellichaam, CWISE J124909.08+362116.0 genaamd maar kortweg CWISE J1249 genoemd, heeft zo'n lage massa dat het moeilijk te classificeren is. Volgens onderzoekers zou het desondanks een kleine ster of een bruine dwerg kunnen zijn. Maar waarom beweegt hij zo snel?

Waarom zo'n hoge snelheid?

NASA/JPL-Caltech

Alleen al binnen het project Backyard Worlds: Planet 9 zijn er al meer dan 4000 bruine dwergen geïdentificeerd, hemellichamen die het midden houden tussen een gasvormige planeet zoals Jupiter en een ster zoals de zon. Geen van hen beweegt echter met zo'n hoge snelheid dat ze zouden kunnen ontsnappen aan de zwaartekracht van de Melkweg. Bovendien heeft CWISE J1249 een andere samenstelling dan de andere bruine dwergen en sterren in ons melkwegstelsel, omdat hij minder ijzer en andere metalen bevat: hij zou deel kunnen uitmaken van de eerste generatie sterren in de Melkweg. 

Over zijn snelheid hebben wetenschappers twee hypotheses bedacht. Aan de ene kant kan de bruine dwerg deel hebben uitgemaakt van een binair systeem met een witte dwerg, die op een gegeven moment explodeerde als supernova en zo de ontsnapping van CWISE J1249 in gang zette. Aan de andere kant zou de snelheid veroorzaakt kunnen zijn door een ontmoeting met een binair systeem gevormd door twee zwarte gaten, waarvan de interacties de bruine dwerg de ruimte in zouden hebben geslingerd. En uit de Melkweg.

Het belang van Backyard Worlds: Planet 9

De ontdekking van CWISE J1249 en zijn ontsnapping aan de zwaartekracht van de Melkweg is slechts het laatste succes van Backyard Worlds: Planet 9. Het project bevordert de samenwerking tussen duizenden astronomen wereldwijd en heeft het mogelijk gemaakt om enorme hoeveelheden astronomische gegevens te analyseren. Het project bevordert de samenwerking tussen duizenden liefhebbers van de astronomie over de hele wereld en heeft het mogelijk gemaakt om enorme hoeveelheden astronomische gegevens te analyseren, vergelijkbaar met het project Black Hole Finder voor het zoeken naar zwarte gaten. Terwijl Backyard Worlds: Planet 9 ook uitgaat van het idee van het bestaan van een negende planeet in het zonnestelsel voorbij Neptunus, is het een initiatief dat heeft geleid tot de ontdekking van vele bruine dwergen en andere hemellichamen in ons melkwegstelsel.

In dit opzicht is het project een perfect voorbeeld van hoe wetenschap en passie voor de astronomie tot buitengewone resultaten kunnen leiden. Waaronder de ontdekking van een ster die ontsnapt uit de Melkweg, het eerste voorbeeld van een hemellichaam met zo'n hoge snelheid dat het ontsnapt aan de galactische zwaartekracht, maar niet aan onze ogen.

{ https://www.curioctopus.nl/ }

04-09-2024 om 21:49 geschreven door peter  

Most people consider Saturn's awe-inspiring system of rings that encircle the gas giant to be the most fascinating and iconic celestial feature in our solar system.

Back in the 17th century, Italian astronomer Galileo Galilei first spied Saturn through his ancient telescope. He compared the planet's appearance to having "ears" due to the limitations of his device.

The diligent work of scientists like Galileo Galilei has laid the foundation for our modern-day ability to explore the incredible wonders of our universe.

Over the years, advances in technology and innovative techniques have empowered astronomers, such as Dr. Lucy Jones from the esteemed Harvard-Smithsonian Center for Astrophysics (CfA), to delve deeper into the enigmas surrounding celestial bodies.

Through cutting-edge research and observations, they have unraveled the intricate mysteries of Saturn's rings, revealing their composition and the dynamic processes that shape them.

Cosmic vanishing act

A fast-approaching and significant cosmic event will soon dramatically alter our view of this magnificent planet. Come March 2025, Saturn's majestic rings will become virtually invisible to earth-based observers.

This phenomenon occurs due to the unique tilt of Saturn's axis, which will position the rings edge-on to our line of sight.

Related video: 

• Saturn and the moon to join side by side on Aug. 20 (Dailymotion)

As a result, this is a rare opportunity for citizens and astronomers alike to witness this celestial transformation, while also reminding us of the ever-changing nature of our universe.

Thankfully, this isn't a permanent change. It's a fleeting cosmic event that recurs every 29.5 years, which is how long it takes Saturn to orbit the Sun. After March 2025, Saturn's axial tilt will bring the rings back into view, then vanish again in November 2025.

So, the rings are not really disappearing but rather playing a celestial game of hide and seek. At their reappearance, we can also enjoy an accentuated view of Saturn's moons.

Saturn's ring structure

So, what are Saturn's rings really made of? Mostly, they consist of ice particles, rocky debris, and cosmic dust, creating a stunning spectacle visible from Earth with a telescope.

Picture a bustling city with buildings of all sizes. Similarly, the ring particles vary from tiny grains, about the size of sand, to huge chunks as big as houses or even school buses. This mix gives the rings their intriguing look.

Saturn's rings aren't just one solid structure. They're made up of several distinct sections, including the A, B, and C rings, along with the fainter D, E, F, and G rings that are harder to see.

These sections are separated by gaps, like the well-known Cassini Division between the A and B rings, which is around 4,800 kilometers wide. The shapes and setups of these rings are mainly shaped by gravitational interactions with Saturn's many moons.

Some of these moons, dubbed "shepherd moons," hang out near the edges of the rings and help keep things in shape by pulling on the ring particles with their gravity.

As for how Saturn's rings came to be, that's still a hot topic among astronomers. There are plenty of theories, from being the leftovers of a destroyed moon or comet that got torn apart by Saturn's strong gravity to materials left over from when Saturn formed over 4 billion years ago.

Each theory has its own fascinating ideas, and ongoing research keeps revealing new insights about these amazing structures that orbit the planet.

Importance of the Cassini-Huygens Mission

The Cassini-Huygens mission was an amazing collaboration between NASA, the European Space Agency (ESA), and the Italian Space Agency (ASI).

This ambitious journey to uncover the cool mysteries of Saturn and its stunning rings started when the spacecraft arrived at Saturn in 2004, kicking off a thorough 13-year exploration that wrapped up in 2017.

Throughout its journey, the Cassini-Huygens mission brought us a treasure trove of information about Saturn and its complex system. One of the coolest finds was discovering gaps in the rings, especially the Cassini Division, which is the noticeable space between the A and B rings.

This division is shaped by the gravitational pull of Saturn's moons, showcasing how dynamic and ever-changing the ring system really is.

The mission also gave us deeper insights into Saturn's many moons, revealing their unique compositions and geological features. For example, Enceladus, one of Saturn's icy moons, has geysers that shoot out water vapor and organic materials, hinting at the possibility of subsurface oceans.

Thanks to the Cassini-Huygens mission, scientists gained valuable insights into the intricate dance of moons and rings around Saturn, completely transforming our understanding of the planet and its unique traits.

Saturn's moons and magnetic field

There is much more to Saturn than just those incredible rings. In fact, Saturn boasts a minimum of 145 moons, each with its own unique characteristics and mysteries.

Among these, Titan, the second-largest moon in the Solar System, truly steals the show with its thick atmosphere and intriguing surface. Interestingly, Titan has a magnetic field that, while weaker than Jupiter's, is stronger than Earth's, indicating complex interactions with Saturn's magnetic environment.

Titan radiates powerful radio waves, particularly from its spectacular auroras at the poles, which can provide valuable insights into both Titan's atmosphere and the overall dynamics of Saturn's magnetic field. The upcoming Dragonfly mission will search for life on Titan.

That said, Titan's mysteries pale in comparison to what we might find on Enceladus. Cassini discovered the presence of vital components for life on this icy Saturnian moon. 

Based on this data, experts have identified crucial organic compounds and a potent energy source, hinting at the moon's potential to support life.

"Not only does Enceladus seem to meet the basic requirements for habitability, we now have an idea about how complex biomolecules could form there, and what sort of chemical pathways might be involved," explains Jonah Peter, a doctoral student at Harvard University who conducted the research while working at NASA's Jet Propulsion Laboratory.

Stargazers, Saturn, and those magnificent rings

To sum it all up, as Saturn's rings prepare to vanish from view in March 2025, stargazers have a unique opportunity to witness this fleeting cosmic event.

The rings will align edge-on with Earth, making them virtually invisible and highlighting the dynamic nature of celestial objects.

For now, Saturn remains a captivating target for those with telescopes or high-powered binoculars. The planet's stunning rings, composed of countless ice particles and rocky debris, offer a glimpse into the complex and beautiful structure of our solar system.

{ https://www.msn.com/en-us/ }

03-09-2024 om 23:57 geschreven door peter  

De lancering maakt deel uit van ESA's Sentinel 2-programma, een project dat in samenwerking met de Europese Commissie loopt. De Sentinel-2C zal de Sentinel-2A vervangen. Die was gelanceerd in juni 2015 en intussen staan we heel wat verder, wat voor een grote verbetering zal zorgen in de aangeleverde data. Dat zegt Inge Jonckheere van de ESA in een gesprek met VRT NWS.

Jonckheere werkt als directeur van de Green Solutions Division bij ESA die satellietdata gebruikt voor alle mogelijke wetenschappelijke en maatschappelijke toepassingen, specifiek dan voor het observeren van de aarde, het milieu en het klimaat. 

Over de missie

De Sentinel 2-missie telt 2 identieke satellieten, Sentinel 2A (gelanceerd in 2015) en Sentinel 2B (2017), die in dezelfde baan vliegen maar 180 graden uit elkaar om de dekking en de revisit-tijd te optimaliseren. De satellieten draaien elke 100 minuten in een baan om de aarde en bestrijken elke 5 dagen alle landoppervlakken, grote eilanden, binnenwateren en kustwateren.

Eenmaal in een baan om de aarde zal Sentinel-2C zijn voorganger Sentinel-2A vervangen, terwijl Sentinel-2D later Sentinel-2B zal vervangen om de continuïteit van gegevens na 2035 te waarborgen.

Sneller data, en een goed oog

De combinatie met de nog actieve Sentinel-2B wordt voortaan beter. Er zullen vaker data binnenlopen, wetenschappers zullen zowat om de week een update krijgen van wat er op de grond gebeurt. 

"We zullen met deze satellietcombinatie elke 5 tot 10 dagen beeld hebben van een specifiek gebied, afhankelijk van de breedtegraad - tegenover ongeveer tweewekelijks met 1 satelliet - waardoor de tijdsresolutie preciezer wordt", zegt Jonckheere.   

"We krijgen daardoor bijna continu een aanvoer van data. En hoe meer data je hebt, hoe beter de opvolging van natuurlijke processen en extreme events."

En er is meer. De nieuwe optische satelliet heeft ook een relatief scherp oog. "Je moet rekenen op een grondresolutie van 10 tot 30 meter, wat relatief gezien behoorlijk nauwkeurig is. Sommige satellieten die gebruikt worden voor het klimaat hebben amper een paar kilometer resolutie."

Het is wel zo dat wolken de observatie kunnen verstoren, maar net daarvoor is het zo belangrijk dat de omlooptijd door het gebruik van de 2 satellieten nu een stuk korter gaat worden. 

Van methaan tot algenbloei in het water

De nieuwe satelliet heeft toepassingen voor landbouw, waterkwaliteit, natuurrampen en de uitstoot van het sterke broeikasgas methaan. 

De ESA gaf deze illustratie vrij van de lancering van de Sentinal-2C.

© Foto: ESA

Zoveel mogelijk op eigen benen staan in tijden van AI (en fake data)

De lancering is niet enkel van belang voor meer en betere data. Het gaat er ook om dat Europa zelf zoveel mogelijk op eigen benen wil staan wat betreft datagaring. Momenteel is er voor zulke aardobservatie- programma's veel samenwerking met bijvoorbeeld de Amerikaanse ruimtevaartorganisatie NASA en/of met China, en worden veel data samengelegd.

{ https://www.msn.com/nl-be/ }

03-09-2024 om 23:39 geschreven door peter  

Ganymede Was Struck by Giant Asteroid 4 Billion Years Ago, New Research Suggests

Jupiter’s moon Ganymede has an ancient impact structure called a furrow system. This system is the largest impact structure in the outer Solar System, and the impact should have significantly affected Ganymede’s early history.

Distribution of furrows and location of the center of the furrow system shown in the hemisphere that always faces away from Jupiter (top) and the cylindrical projection map of Ganymede (bottom). The gray regions represent geologically young terrain without furrows. Furrows (green lines) exist only on geologically old terrains (black regions).

Image credit: Naoyuki Hirata, doi: 10.1038/s41598-024-69914-2.

Ganymede is the largest satellite in the Solar System and has many unique features, including tectonic troughs known as furrows.

Furrows are the oldest surface features recognized on Ganymede because they are crosscut by any impact craters with diameters exceeding 10 km. They can provide a window into the early history of this moon.

{ https://www.sci.news/ }

03-09-2024 om 22:25 geschreven door peter