The study was led by Ryan Park, a Senior Research Scientist and Principal Engineer at NASA’s Jet Propulsion Laboratory (JPL). He was joined by multiple colleagues from NASA JPL, the Centro Interdipartimentale di Ricerca Industriale Aerospaziale (CIRI) at the Università di Bologna, the National Institute for Astrophysics (NIAF), the Sapienza Università di Roma, the Southwest Research Institute (SwRI), and NASA’s Goddard Space Flight Center, and multiple universities. Their findings were described in a paper that appeared in the journal Nature.

As they explain in their paper, two types of analysis have predicted the existence of a global magma ocean. On the one hand, magnetic induction measurements conducted by the Galileo mission suggested the existence of a magma ocean within Io, approximately 50 km [~30 mi] thick and located near the surface. These results also implied that about 20% of the material in Io’s mantle is melted. However, these results were subjected to debate for many years. In recent years, NASA’s Juno mission conducted multiple flybys of Io and the other Jovian moons and obtained data that supported this conclusion.

In particular, the Juno probe conducted a global mapping campaign of Io’s volcanoes, which suggested that the distribution of volcanic heat flow is consistent with the presence of a global magma ocean. However, these discoveries have led to considerable debate about these techniques and whether they can be used to distinguish whether a shallow global magma ocean drives Io’s volcanic activity. This is the question Park and his colleagues sought to address in their study:

“In our study, Io’s tidal deformation is modeled using the gravitational tidal Love number k₂, which is defined as the ratio of the imposed gravitational potential from Jupiter to the induced potential from the deformation of Io. In short, if k₂ is large, there is a global magma ocean, and if k₂ is small, there is no global magma ocean. Our result shows that the recovered value of k₂ is small, consistent with Io not having a global magma ocean.”

The significance of these findings goes far beyond the study of Io and other potentially volcanic moons. Beyond the Solar System, astronomers have discovered countless bodies that (according to current planetary models) experience intense tidal heating. This includes rocky exoplanets that are several times the size and mass of Earth (Super-Earths) and in the case of tidally-locked planets like the TRAPPIST-1 system. These findings are also relevant for the study of exomoons that also experience intense tidal heating (similar to the Jovian moons). As Park explained:

“Although it is commonly assumed among the exoplanet community that intense tidal heating may lead to magma oceans, the example of Io shows that this need not be the case. Our results indicate that tidal forces do not universally create global magma oceans, which may be prevented from forming due to rapid melt ascent, intrusion, and eruption, so even strong tidal heating – like that expected on several known exoplanets and super-Earths – may not guarantee the formation of magma oceans on moons or planetary bodies.”

Further Reading: 

• Nature

{  https://www.universetoday.com/ }

19-12-2024 om 18:34 geschreven door peter  

Posted by Evan Gough

The JWST Looked Over the Hubble’s Shoulder and Confirmed that the Universe is Expanding Faster

It’s axiomatic that the Universe is expanding. However, the rate of expansion hasn’t remained the same. It appears that the Universe is expanding more quickly now than it did in the past.

Astronomers have struggled to understand this and have wondered if the apparent acceleration is due to instrument errors. The JWST has put that question to rest.

American astronomer Edwin Hubble is widely credited with discovering the expansion of the Universe. But it actually stemmed from relativity equations and was pioneered by Russian scientist Alexander Freedman. Hubble’s Law bears Edwin’s name, though, and he was the one who confirmed the expansion, called Hubble’s constant, and put a more precise value to it. It measures how rapidly galaxies that aren’t gravitationally bound are moving away from one another. The movement of objects due solely to the Hubble constant is called the Hubble flow.

Measuring the Hubble constant means measuring distances to far-flung objects. Astronomers use the cosmic distance ladder (CDL) to do that. However, the ladder has a problem.

The first rungs on the CDL are fundamental measurements that can be observed directly. Parallax measurement is the most important fundamental measurement. But the method breaks down at great distances.

Beyond that, astronomers use standard candles, things with known intrinsic brightness, like supernovae and Cepheid variables. Those objects and their relationships help astronomers measure distances to other galaxies. This has been tricky to measure, though advancing technology has made progress.

Another pair of problems plagues the effort, though. The first is that different telescopes and methods produce different distance measurements. The second is that our measurements of distances and expansion don’t match up with the Standard Model of Cosmology, also known as the Lambda Cold Dark Matter (LCDM) model. That discrepancy is called the Hubble tension.

The question is, can the mismatch between the measurements and the LCDM be explained by instrument differences? That possibility has to be eliminated, and the trick is to take one large set of distance measurements from one telescope and compare them to another.

New research in The Astrophysical Journal tackles the problem by comparing Hubble Space Telescope measurements with JWST measurements. It’s titled “JWST Validates HST Distance Measurements: Selection of Supernova Subsample Explains Differences in JWST Estimates of Local H₀.” The lead author is Adam Riess, a Bloomberg Distinguished Professor and Thomas J. Barber Professor of Physics and Astronomy at Johns Hopkins University. Riess is also a Nobel laureate, winning the 2011 Nobel Prize in Physics “for the discovery of the accelerating expansion of the Universe through observations of distant supernovae,” according to the Nobel Institute.

As of 2022, the Hubble Space Telescope gathered the most numerous sample of homogeneously measured standard candles. It measured a large number of standard candles out to about 40 Mpc or about 130 million light-years. “As of 2022, the largest collection of homogeneously measured SNe Ia is complete to D less than or equal to 40 Mpc or redshift z less than or equal to 0.01,” the authors of the research write. “It consists of 42 SNe Ia in 37 host galaxies calibrated with observations of Cepheids with the Hubble Space Telescope (HST), the heritage of more than 1000 orbits (a comparable number of hours) invested over the last ~20 yrs.”

In this research, the astronomers used the powerful JWST to cross-check the Hubble’s work. “We cross-check the Hubble Space Telescope (HST) Cepheid/Type Ia supernova (SN Ia) distance ladder, which yields the most precise local H₀ (Hubble flow), against early James Webb Space Telescope (JWST) subsamples (~1/4 of the HST sample) from SH0ES and CCHP, calibrated only with NGC 4258,” the authors write. SH0ES and CCHP are different observing efforts aimed at measuring the Hubble constant. SH0ES stands for Supernova H0 for the Equation of State of Dark Energy, and CCHP stands for Chicago-Carnegie Hubble Program, which uses the JWST to measure the Hubble constant.

“JWST has certain distinct advantages (and some disadvantages) compared to HST for measuring distances to nearby galaxies,” Riess and his co-authors write. It offers a 2.5 times higher near-infrared resolution than the HST. Despite some of its disadvantages, the JWST “is able to provide a strong cross-check of distances in the first two rungs,” the authors explain.

Observations from both telescopes are closely aligned, which basically minimizes instrument error as the cause of the discrepancy between observations and the Lambda CDM model.

“While it will still take multiple years for the JWST sample of SN hosts to be as large as the HST sample, we show that the current JWST measurements have already ruled out systematic biases from the first rungs of the distance ladder at a much smaller level than the Hubble tension,” the authors write.

This research covered about one-third of the Hubble’s data set, with the known distance to a galaxy called NGC 4258 serving as a reference point. Even though the data set was small, Riess and his co-researchers achieved impressively precise results. They showed that the measurement differences were less than 2%. That’s much less than the 8% to 9% in the Hubble tension discrepancy.

That means that our Lamda CDM model is missing something. The standard model yields an expansion rate of about 67 to 68 kilometres per second per megaparsec. Telescope observations yield a slightly higher rate: between 70 and 76 kilometres per second per megaparsec. This work shows that the discrepancy can’t be due to the different telescopes and methods.

“The discrepancy between the observed expansion rate of the universe and the predictions of the standard model suggests that our understanding of the universe may be incomplete. With two NASA flagship telescopes now confirming each other’s findings, we must take this [Hubble tension] problem very seriously—it’s a challenge but also an incredible opportunity to learn more about our universe,” said lead author Riess.

What could be missing from the Lambda CDM model?

Marc Kamionkowski is a Johns Hopkins cosmologist who helped calculate the Hubble constant and recently developed a possible new explanation for the tension. Though not part of this research, he commented on it in a press release.

“One possible explanation for the Hubble tension would be if there was something missing in our understanding of the early universe, such as a new component of matter—early dark energy—that gave the universe an unexpected kick after the big bang,” said Kamionkowski. “And there are other ideas, like funny dark matter properties, exotic particles, changing electron mass, or primordial magnetic fields that may do the trick. Theorists have license to get pretty creative.”

The door is open, theorists just have to walk in.

{ https://www.universetoday.com/ }

19-12-2024 om 18:11 geschreven door peter  

New Study Examines Elusive Nature of Martian Liquid Brines

Mars is located at the extreme limits of brine stability; and only a combination of the most favorable environmental conditions and lowest eutectic temperature salts allows for brines to be at least temporarily stable on the Martian surface, according to a new study published in the Proceedings of the National Academy of Sciences.

This image of an impact crater in the Sirenum Fossae region of Mars was taken by NASA’s Mars Reconnaissance Orbiter on March 30, 2015. The crater is approximately 3,300 feet (1-km) wide and appears relatively recent as it has a sharp rim and well-preserved ejecta. The steep inner slopes are carved by gullies and include possible recurring slope lineae on the equator-facing slopes.

Image credit: NASA / JPL / University of Arizona / Alfred McEwen.

Liquid water is a critical precondition for a habitable planet. Yet the combination of low temperature, atmospheric pressure and water vapor pressure on Mars means any liquid water found there would likely freeze, boil or evaporate immediately, making its presence unlikely.

Yet palnetary researchers continue to make the case for the presence of liquid water on the Red Planet.

Of particular interest has been the discovery of seasonal dark streaks called the recurring slope lineae.

These features appear in several locations on Mars when temperatures are above minus 23 degrees Celsius (minus 10 degrees Fahrenheit), and disappear at colder times.

They often have been described as possibly related to liquid water.

The new study throws cold water on the notion that we are likely find liquid water on Mars in recurring slope lineae, permafrost or brines anytime soon.

“A closer look at RSLs indicates their behavior is consistent with sand and dust flows with no water needed to create them,” said lead author Dr. Vincent Chevrier, a researcher at the University of Arkansas.

Other researchers think that brines, which are solutions with a high concentration of salts, such as Earth’s oceans, may hold the key to finding liquid water on Mars.

Brines can freeze at much lower temperatures, and there is an abundance of salts on Mars.

Of those salts, perchlorates would seem to be the most promising, since they have extremely low eutectic temperatures (which is when the melting point of a mixture is lower than any single ingredient).

For instance, a calcium perchlorate brine solidifies at minus 75 degrees Celsius (14 degrees Fahrenheit), while Mars has an average surface temperature of minus 50 degrees Celsius (minus 58 degrees Fahrenheit) at the equator, theoretically suggesting there could be a zone where calcium perchlorate brine could stay liquid, particularly in the subsurface.

Dr. Chevrier and his colleague, Dr. Rachel Slank from the Lunar and Planetary Institute, then examined all of the arguments for and against brines potentially forming stable liquids.

“The various limiting factors, including the relatively low amounts of the most promising salts, water vapor pressure and ice location strongly limit the abundances of brines on the surface or shallow subsurface,” they said.

“And even if brines did form, they would remain highly un-habitable by terrestrial standards.”

“Despite these drawbacks and limitations, there is always the possibility that Martian life adapted to those brines and some terrestrial organisms could survive in them, which is a consideration for planetary protection because life on Mars might exist today in that case.”

“Hence, detecting brines in situ remains a major objective of the exploration of the Red Planet.”

Moving forward, the authors suggest the next hurdles will be improving the instruments needed to detect small amounts of brines, doing a better job of identifying the best places to look for them, and being able to conduct more laboratory measurements under Martian conditions.

“Despite our best efforts to prove otherwise, Mars still remains a cold, dry and utterly unhabitable desert,” Dr. Chevrier said.

• Vincent F. Chevrier & Rachel A. Slank. 2024. The elusive nature of Martian liquid brines. PNAS 121 (52): e2321067121; doi: 10.1073/pnas.2321067121

{ https://www.sci.news/ }

18-12-2024 om 23:59 geschreven door peter  

When we think about unexpected events, asteroid impacts are typically quite low on the list. After all, a large asteroid colliding with Earth is highly unlikely in the foreseeable future.

However, given the potential catastrophic damage that such an event could cause, experts from NASA have made it a priority to plan for this distant possibility.

Every two years, a special branch of NASA, the Jet Propulsion Laboratory’s (JPL) Center for Near Earth Object Studies (CNEOS), leads a hypothetical exercise where scientists and decision-makers simulate an asteroid impact scenario.

The goal of these exercises, involving both federal and international agencies, is to address the uncertainties tied to an asteroid strike.

Grand schemers of disaster prep

CNEOS, based in Southern California, has been instrumental in formulating these disaster management exercises for over a decade.

These specialists are tasked with the crucial job of tracking and classifying asteroids and comets, in addition to identifying potential threats to Earth.

Paul Chodas, director of CNEOS, sheds light on the painstaking nature of these drills.

“These hypothetical scenarios are complex and take significant effort to design, so our purpose is to make them useful and challenging for exercise participants and decision-makers,” he explains.

By honing their processes and procedures, the team becomes better equipped to formulate an effective plan of action in case of actual threats, filling any gaps in the planetary defense community’s knowledge.

Earth and asteroid impact scenario

This year’s simulation brought the ‘what if’ into alarming focus. Imagining a hypothetical asteroid of considerable size, the team calculated a 72% chance of it striking Earth in 14 years.

Potential impact locations included heavily populated areas across North America, Southern Europe, and North Africa. However, there was also a substantial 28% chance that the asteroid would entirely miss Earth.

Once in close proximity to the Sun, further observation of the asteroid was deemed impossible for the next seven months, leaving decision-makers in a quandary concerning what to do next.

“This was a very successful tabletop exercise, with nearly 100 participants from U.S. government agencies and, for the first time, international planetary defense experts,” said Terik Daly from APL, who coordinated the exercise.

“An asteroid impact would have severe national and international ramifications, so should this scenario play out for real, we’d need international collaboration.”

Global team takes clues from reality

These simulations are a collaborative endeavor. Participants include NASA’s Planetary Defense Coordination Office (PDCO), the Federal Emergency Management Agency Response Directorate (FEMA Response), and the Department of State Office of Space Affairs.

Earlier this year, nearly 100 participants from various U.S. government agencies gathered in Laurel, Maryland, at the Johns Hopkins Applied Physics Laboratory (JHUAPL).

For the first time, international planetary defense experts were also part of this event, highlighting the need for global cooperation in handling such potential crises.

To make the scenario more realistic, the CNEOS team simulated all the observations leading up to the exercise.

“At this point in time, the impact was likely but not yet certain, and there were significant uncertainties in the object’s size and the impact location,” said Davide Farnocchia, a navigation engineer at JPL and CNEOS, who led the design of the asteroid’s orbit.

“It was interesting to see how this affected the decision-makers’ choices and how the international community might respond to a real-world threat 14 years out.”

Shields up: Averting potential disaster

Among the remarkable scientists pioneering asteroid deflection missions is the team behind the Double Asteroid Redirection Test (DART).

This mission was a monumental success and has provided foundations for future asteroid deflection efforts.

The process behind this isn’t as simple as playing cosmic billiards, though. It involves years of preparation and planning, requiring advanced observatories capable of detecting hazardous asteroids as early as possible.

The Near-Earth Object Surveyor (NEOS), an infrared space telescope slated for launch in late 2027, plays a significant role in achieving this mission.

Understanding Near-Earth Objects (NEOs)

Near-Earth objects (NEOs) are space rocks that come close to Earth’s orbit, including both asteroids and comets.

NEOs come in a wide range of sizes. Some are just a few meters across, while others can be kilometers in diameter.

Even small NEOs can cause significant damage if they collide with Earth, and large ones could lead to catastrophic events.

Many NEOs contain ancient materials from the early solar system. Studying these materials can give us insights into how planets and other celestial bodies formed and evolved.

Past lessons and future preparations

Let’s be honest. The idea of asteroid impacts may sound like a storyline lifted straight from a blockbuster movie script. But the effects of such celestial encounters are very real and potentially devastating.

The Tunguska event of 1908 serves as a grim reminder. A small asteroid exploded above Siberia, flattening approximately 80 million trees over an area stretching 800 square miles.

More recently, the Chelyabinsk meteor in 2013 shook Russia, causing extensive injuries and property damage due to the resulting shockwave.

In light of past events and the potential risks they pose, NASA employs a comprehensive approach that consists of proactive and reactive strategies.

Proactively, missions like DART are integral to developing techniques to alter an asteroid’s course. Infrared space telescopes like the Near-Earth Object Surveyor aim to spot and classify potentially dangerous objects long before they become a threat.

Reactively, NASA has established emergency response exercises to ensure global coordination and swift decision-making processes are in place.

Protecting Earth from asteroids

NASA’s asteroid impact exercises serve as a stark reminder of the potential threats lurking in the cosmos.

These exercises simulate scenarios where an asteroid might be on a collision course with Earth, challenging scientists to develop effective strategies for deflection or mitigation.

Yet, they also highlight our abilities to strategize, collaborate, and leverage advanced technology in the face of such dangers.

By bringing together experts from diverse fields, from astronomy to engineering, these exercises foster innovation and preparedness.

Do you feel safer knowing about the measures in place?

Let’s continue our vigilance because, as the saying goes, “Forewarned is forearmed.” Every step we take today could be crucial for protecting our planet tomorrow.

Next time you look up at the night sky, remember the unsung heroes of space working tirelessly to safeguard our planet. Because as we’ve learned, the best offense can often be a great defense.

• To find out the outcome of the exercise, read NASA’s preliminary summary.

VIDEOS

{ https://www.earth.com/ }

18-12-2024 om 23:24 geschreven door peter  

Nasa astronauts Butch and Suni's homecoming delayed again

 Pallab Ghosh - Science Correspondent

VIDEOS

{ https://www.bbc.com/ }

18-12-2024 om 22:56 geschreven door peter  

Posted by Mark Thompson

Drone Test Flights Are Being Tested for Flights on Alien Worlds

We’ve already seen the success of the Ingenuity probe on Mars. The first aircraft to fly on another world set off on its maiden voyage in April 2021 and has now completed 72 flights. Now a team of engineers are taking the idea one step further and investigating ways that drones can be released from satellites in orbit and explore the atmosphere without having to land. The results are positive and suggest this could be a cost effective way to explore alien atmospheres. 

The idea of using drones on alien worlds has been enticing engineers and planetary explorers for a few years now. They’re lightweight and versatile and an excellent cost effective way to study the atmosphere of the planets. Orbiters and rovers have been visiting the planets for decades now but drones can explore in ways rovers and orbiters cannot. Not only will they be useful to study atmospheric effects but they will be able to reach inaccessible surface areas providing imagery to inform potential future land based study. 

Perhaps one of the most famous, indeed the only successful planetary drone to date is the Ingenuity drone which was part of the Perseverance rover mission. It was able to demonstrate that controlled flight in the Martian atmosphere was possible, could hunt out possible landing sites for future missions and direct ground based exploration. It’s iconic large wingspan was needed due to the rarefied atmosphere on Mars requiring larger rotor blades to generate the required lift. Ingenuity was originally planned as a technology demonstration mission but it soon became a useful tool in the Perseverance mission arsenal. 

NASA engineers are very aware of the benefits of drone technology and so a team of engineers and researchers from the Armstrong Flight Research Center in California have been taking the idea of small drones one step further. The research was part of the Center Innovation Fund award from 2023 and began as the team developed three atmospheric probe models. The models were all the same, measuring 71 cm from top to bottom, one for visual demonstration, the other two for research and technology readiness. 

Justin Link, left, small unmanned aircraft systems pilot; John Bodylski, atmospheric probe principal investigator; and Justin Hall, chief pilot of small unmanned aircraft systems, discuss details of the atmospheric probe flight plan on Oct. 22, 2024. A quad rotor remotely piloted aircraft released the probe above Rogers Dry Lake, a flight area adjacent NASA’s Armstrong Flight Research Center in Edwards, California. The probe was designed and built at the center.

NASA/Steve Freeman

Justin Hall, chief pilot of small unmanned aircraft systems, prepares the atmospheric probe for flight above Rogers Dry Lake, a flight area adjacent NASA’s Armstrong Flight Research Center in Edwards, California. At right, Justin Link, small unmanned aircraft systems pilot, assists. The probe, designed and built at the center, flew after release from a quad rotor remotely piloted aircraft on Oct. 22, 2024.

NASA/Steve Freeman

Derek Abramson, left, chief engineer for the Dale Reed Subscale Flight Research Laboratory, and Justin Link, small unmanned aircraft system pilot, carry the atmospheric probe model and a quad rotor remotely piloted aircraft to position it for flight on Oct. 24, 2024. John Bodylski, probe principal investigator, right, and videographer Jacob Shaw watch the preparations. Once at altitude, the quad rotor aircraft released the probe above Rogers Dry Lake, a flight area adjacent to NASA’s Armstrong Flight Research Center in Edwards, California. The probe was designed and built at the center.

NASA/Steve Freeman

A quad rotor remotely piloted aircraft releases the atmospheric probe model above Rogers Dry Lake, a flight area adjacent NASA’s Armstrong Flight Research Center in Edwards, California, on Oct. 22, 2024. The probe was designed and built at the center.

NASA/Carla Thomas

Their first launch on 1 August didn’t go to plan with a failure in the release mechanism. The team reviewed everything from the lifting aircraft, the release mechanism and even the probe design itself to identify improvements. The team were finally able to conduct flights with their new atmospheric probe after it was released from a quad rotor remotely piloted aircraft on 22 October 2024. 

The flights were conducted above the Rogers Dry Lake near in California with designs informed by previous NASA instrumentation designed for lifting and transportation. The test flights were aiming to prove the shape of the probe worked. The team now want to release the probe from a higher altitude, ultimately hoping to be able to release it from a satellite in orbit around a planet. 

The next steps are to review photos and videos from the flight to identify further improvements before another probe is built. Once they have probed the flight technology, instrumentation will be added to facilitate data gathering and recording. If all goes to plan then the team hope to be chosen for a mission to one of the planets, be released in orbit and then dive into the atmosphere under controlled flight to learn more about the environment. 

Source : 

• Atmospheric Probe Shows Promise in Test Flight

NASA/Steve Parcel

{ https://www.universetoday.com/ }

18-12-2024 om 18:13 geschreven door peter  

Astronomers don’t know how these ancient, bulging galaxies formed and evolved. However, a new research letter in Nature may finally have the answer. It’s titled “In situ spheroid formation in distant submillimetre-bright galaxies.” The lead author is Qing-Hua Tan from the Purple Mountain Observatory, Chinese Academy of Sciences, China. Dr. Annagrazia Puglisi from the University of Southampton co-authored the research.

The international team of researchers used the Atacama Large Millimetre/sub-millimetre Array (ALMA) to examine highly luminous starburst galaxies in the distant Universe. Sub-millimetre means it observes electromagnetic energy between far-infrared and microwave. Astronomers have suspected for a long time that these galaxies are connected to spheroids, but observing them is challenging.

“Infrared/submillimetre-bright galaxies at high redshifts have long been suspected to be related to spheroid formation,” the authors write. “Proving this connection has been hampered so far by heavy dust obscuration when focusing on their stellar emission or by methodologies and limited signal-to-noise ratios when looking at submillimetre wavelengths.”

The researchers used ALMA to analyze more than 100 of these ancient galaxies with a new technique that measures their distribution of light. These brightness profiles show that the majority of the galaxies have tri-axial shapes rather than flat disks, indicating that something in their history made them misshapen.

Two important concepts underpin the team’s results: The Sersic index and the Spergel index.

The Sersic index is a fundamental concept in describing the brightness profiles of galaxies. It characterizes the radial distribution of light coming from galaxies and basically describes how light is concentrated in a galaxy.

The Spergel index is less commonly used. It’s based on the distribution of dark matter in galaxies. Rather than light, it helps astronomers understand how matter is concentrated. Together, both indices help astronomers characterize the complex structure of galaxies.

These indices, along with the new ALMA observations, led to new insights into how spheroids formed through mergers and the resulting influx of cold, star-forming gas.

It all starts with a galaxy collision or merger, which sends large flows of cold gas into the galactic centre.

“Two disk galaxies smashing together caused gas—the fuel from which stars are formed—to sink towards their centre, generating trillions of new stars,” said co-author Puglisi. “These cosmic collisions happened some eight to 12 billion years ago when the universe was in a much more active phase of its evolution.”

“This is the first real evidence that spheroids form directly through intense episodes of star formation located in the cores of distant galaxies,” Puglisi said. “These galaxies form quickly—gas is sucked inwards to feed black holes and triggers bursts of stars, which are created at rates ten to 100 times faster than our Milky Way.”

The researchers compared their observations to hydro-simulations of galaxy mergers. The results show that the spheroids can maintain their shape for up to approximately 50 million years after the merger. “This is compatible with the inferred timescales for the submillimeter-bright bursts based on observations,” the authors write. After this intense period of star formation in the spheroid, the gas is used up, and things die down. No more energy is injected into the system, and the residual gas flattens out into a disk.

These types of galaxies were more plentiful in the early Universe than they are now. The researchers’ results show that these galaxies used up their fuel quickly, forming the spheroids that are now populated by old stars.

This isn’t the first time that astronomers have investigated the potential link between spheroids and distant submillimeter-bright galaxies. Previous research that found evidence for tri-axiality also found heavy ellipticity and other evidence showing that submillimeter-bright galaxies are disks with bars in the submillimeter. However, this new research relied on observations with a higher signal-to-noise ratio than previous research.

“Astrophysicists have sought to understand this process for decades,” Puglisi said. “Our findings take us closer to solving a long-standing mystery in astronomy that will redefine our understanding of how galaxies were created in the early universe.”

“This will give us a more complete picture of early galaxy formation and deepen our understanding of how the universe has evolved since the beginning of time.”

{ https://www.universetoday.com/ }

17-12-2024 om 22:07 geschreven door peter  

This is understandable, considering how other forms of energy (fossil fuels, solar, wind, nuclear, hydroelectric, etc.) are either finite or inefficient. Space-based solar power is a viable option since it can provide a steady supply of energy that is not subject to intermittency or weather patterns. Nevertheless, nuclear fusion is considered a major contender for future energy needs because of its efficiency and energy density. It is estimated that one gram of hydrogen fuel could generate as much as 90,000 kilowatt-hours of energy – the equivalent of 11 metric tons (12 U.S. tons) of coal.

In addition, deuterium has a natural abundance in Earth’s oceans of about one atom of deuterium in every 6,420 atoms of hydrogen. This deuterium interacts with water molecules and will replace one or both hydrogen atoms to create “semi-heavy water” (HOD or DOH) and sometimes “heavy water” (D₂O). This works out to 4.85×10¹³ or 48.5 billion metric tons (5.346×10¹³ U.S. tons) of deuterium. As they argue in their paper, extracting deuterium from an ocean would decrease its ratio of deuterium-to-hydrogen (D/H), which would be detectable in atmospheric water vapor. Meanwhile, the helium produced in the nuclear reactions would escape to space.

In recent years, it has been suggested that excess carbon dioxide and radioactive isotopes in an exoplanet’s atmosphere could be used to infer the presence of an industrial civilization. In the same vein, low values of D/H in an exoplanet’s atmosphere (along with helium) could be used to detect a highly advanced and long-lived civilization. As Catling explained in a recent interview with phys.org, this possibility is one he began pondering years ago.

“I didn’t do much with this germ of idea until I was co-organizing an astrobiology meeting last year at Green Bank Observatory in West Virginia,” he said. “Measuring the D/H ratio in water vapor on exoplanets is certainly not a piece of cake. But it’s not a pipe dream either.”

To model what an advanced civilization dependent on DD fusion would look like, Catling and his colleagues considered projections for what Earth will look like by 2100. At this point, the global population is expected to reach 10.4 billion, and fusion power is projected to provide 100 Terawatts (TW). They then multiplied that by a factor of ten (1,000 TW) for a more advanced civilization and found that they would reduce the D/H value of an Earth-like ocean to that of the interstellar medium (ISM) in about 170 million years.

The beauty of this approach is that the low D/H values in an exoplanet’s atmosphere would persist long after a civilization went extinct, migrated off-world, or became even more advanced and “transcended.” In terms of search strategies, the team used the Spectral Mapping Atmospheric Radiative Transfer (SMART) model to identify the specific wavelengths and emission lines for HDO and H₂O. These findings will be useful for future surveys involving the James Webb Space Telescope (JWST), NASA’s proposed Habitable Worlds Observatory (HWO), and the Large Interferometer For Exoplanets (LIFE).

“It’s up to the engineers and scientists designing [HWO] and [LIFE] to see if measuring D/H on exoplanets might be an achievable goal. What we can say, so far, is that looking for D/H from LIFE appears to be feasible for exoplanets with plenty of atmospheric water vapor in a region of the spectrum around 8 microns wavelength.”

Further Reading:

•  phys.org, 
• arXiv

{ https://www.universetoday.com/ }

17-12-2024 om 21:41 geschreven door peter  

In 2018, NASA mission planners selected the Jezero Crater as the future landing site of the Perseverance rover. This crater was a natural choice, as it was once an ancient lake bed, as evidenced by the delta fan at its western edge. On Earth, these features form in the presence of flowing water that gradually deposits sediment over time. Combined with the fact that the Jezero Crater’s delta feature is rich in clays, this makes the region a prime target to search for biosignatures – evidence of past (and maybe present) life on Mars!

In recent news, NASA announced that the Perseverance rover had reached the top of Jezero Crater’s rim at a location the science team calls “Lookout Hill.” The rover spent the previous three and a half months climbing the rim, covering a distance of 500 vertical meters (1,640 vertical feet) and making science observations along the way. Now that it has crested the rim, Perseverance can begin what the mission team calls its “Northern Rim” campaign. Over the next year, the rover is expected to drive 6.4 km (4 mi) and visit up to four sites of interest where it will obtain geological samples.

Since it landed in the Jezero Crater in February 2021, Perseverance has completed four science campaigns. This includes the “Crater Floor,” “Fan Front,” “Upper Fan,” and “Margin Unit” based on where the rover was obtaining samples from. During the first campaign, the rover visited features around its landing site – like the Máaz formation – where it obtained several rock and atmospheric samples, and some witness samples for contamination assessment. The two campaigns that followed saw the rover explore different sections of Jezero’s delta fan and obtain samples of rock and clay.

The fourth campaign, meanwhile, consisted of the rover examining marginal carbonate rocks that circle the upper edge of the Jezero Crater. The science team calls Perseverance’s fifth campaign the “Northern Rim” because its route covers the northern part of the southwestern section of Jezero’s rim. The site was selected so that the rover could explore a region of Mars, unlike anything it has investigated before. Ken Farley, a project scientist for Perseverance at Caltech, explained in a NASA press release:

“The Northern Rim campaign brings us completely new scientific riches as Perseverance roves into fundamentally new geology. It marks our transition from rocks that partially filled Jezero Crater when it was formed by a massive impact about 3.9 billion years ago to rocks from deep down inside Mars that were thrown upward to form the crater rim after impact. These rocks represent pieces of early Martian crust and are among the oldest rocks found anywhere in the solar system. Investigating them could help us understand what Mars — and our own planet — may have looked like in the beginning.”

Now that Perseverance has crested and moved on from Lookout Hill, the rover is heading to a rocky outcrop about 450 m (1,500 feet) on the other side of the rim known as “Witch Hazel Hill.” Said Candice Bedford, a Perseverance scientist from Purdue University:

“The campaign starts off with a bang because Witch Hazel Hill represents over 330 feet [~100 m] of layered outcrop, where each layer is like a page in the book of Martian history. As we drive down the hill, we will be going back in time, investigating the ancient environments of Mars recorded in the crater rim. Then, after a steep descent, we take our first turns of the wheel away from the crater rim toward ‘Lac de Charmes,’ about 2 miles [3.2 km] south.”

Located on the plains beyond the rim, the Lac de Charmes region is of interest to the mission team because it is less likely to have been affected by the impact that led to the Jezero Crater. Beyond that, the rover will travel about 1.6 km (1 mi) back up the rim to investigate an outcropping of blocks (megabreccia) that may be the remains of ancient bedrock broken by another impact. This was the Isidis impact, which occurred 3.9 billion years ago and led to the formation of the Isidis Planitia basin in the Northern Lowlands.

Investigating this site could provide valuable insight into a major surface-reshaping event that took place during the Noachian Period on Mars. This geological epoch saw extensive erosion by flowing water, as indicated by the many river valley networks dated to the period. It is also during the Noachian that the Tharsis Bulge is believed to have formed, indicating that Mars was still geologically active. As always, the ultimate goal is to find biosignatures from this “warmer, wetter” period that indicate that Mars could have had life (similar to Earth at the time).

The Perseverance science team also shared information on the rover, their science operations, and future plans at a media briefing on Thursday, December 12th, during the annual meeting of the American Geophysical Union (AGU) in Washington. As Steven Lee, the deputy project manager for the Perseverance mission at NASA’s Jet Propulsion Laboratory, said during the briefing:

“During the Jezero Crater rim climb, our rover drivers have done an amazing job negotiating some of the toughest terrain we’ve encountered since landing. They developed innovative approaches to overcome these challenges — even tried driving backward to see if it would help — and the rover has come through it all like a champ. Perseverance is ‘go’ for everything the science team wants to throw at it during this next science campaign.”

Further Reading: 

• NASA

{ https://www.universetoday.com/ }

15-12-2024 om 23:10 geschreven door peter  

Posted by Mark Thompson

NASA Thinks it Knows Why Ingenuity Crashed on Mars

NASA’s Ingenuity helicopter sent its final signals to Earth in the earlier part of the year. Engineers have been studying these and have started to piece together a picture of events that led up to its final flight. They concluded that data provided by the navigation system was inaccurate leading to a chain of events that caused its ultimate demise. One of the biggest problems it seems is that the terrain was smooth leading to a lack of landmarks during Flight 72.

Mars is the fourth planet from the Sun and is well known for its distinctive red colour. It’s surface is is covered in iron-oxide which is known by the more common name – rust. The planet is just over half the size of the Earth and has some fascinating geological features like Olympus Mons, the largest volcano in the Solar System. Valles Marineris is a canyon system which stretches thousands of kilometres and dwarfs the Grand Canyon. The atmosphere of the planet is mostly composed of carbon dioxide and currently incapable of supporting life. It’s not thought this has not always been the case and its missions like Mars 2020 that have helped to unravel the mysteries of the red planet. 

The Perseverance Rover and Ingenuity helicopter were both part of the Mars 2020 mission and have been exploring Mars since their launch in 2020 atop an Atlas V rocket. Ingenuity became the first robotic rotorcraft that undertook powered flight in the Martian atmosphere. The inaugural flight took place on 19 April 2021 the 1.8 kilogram drone took off under the power of two counter-rotating blades. The blades of the drone are 1.2m long, oversized by Earth standards but the atmosphere is only 1% as dense as Earth so larger than usual blades are needed. 

Flight 72 was scheduled for the 18th January this year and there was nothing special about it. The plan was a brief vertical hop to checkout the flight systems and to grab some photographs of the area. The flight data revealed it reached an altitude of 12 metres, took the images and was back on the surface after 32 seconds but had severed communications. After communications  was re-established, it was discovered that Ingenuity had sustained damage to its rotors. 

Now, almost a year after the incident, a team of engineers from NASA’s Jet Propulsion Laboratory have been analysing the data. Their findings will be published in the next few weeks however the team of engineers assert it was harder than expected to complete an accident investigation from 160 million kilometres. The faults lie in the navigation system that was designed to visually track surface features using a camera pointed at the round. The system worked during early flights over more textured terrain but as Ingenuity moved over the Jezero Crater, it began operating over featureless sand ripples. 

The navigation system was designed to provide estimates of the helicopter’s velocity, chiefly to enable it to land. The data revealed from Flight 72 revealed that the navigation system couldn’t find features to track. Images showed that the lack of features led to a harden than usual touchdown leading to a pitch and roll of the craft. The sudden change of attitude led to increase load on the rotors, beyond their designed limits leading to the structural damage. 

Even though Ingenuity will not be able to fly anymore it can still provide weather and avionics data to the Perseverance rover. It will help us to understand more about the weather in its vicinity but perhaps its greatest legacy are its hours of flight on an alien world. 

Source : 

• NASA Performs First Aircraft Accident Investigation on Another World

{ https://www.universetoday.com/ }

13-12-2024 om 18:36 geschreven door peter  

• READ MORE: Huge black hole 8,200 times the size of the Sun is discovered 

By WILIAM HUNTER

They are some of the universe's most unusual and fascinating objects.

And now a study suggests that black holes might be even stranger than we thought.

NASA's Chandra X-ray observatory has captured vast plasma jets from a supermassive black hole slamming into a mysterious object.

The researchers who made this bizarre discovery say they have no idea what this galactic speedbump might be or why it seems to act so strangely.

The hidden object lurks within the galaxy Centaurus A, an irregular swirl of gas and dust approximately 12 million light-years from Earth.

What makes Centaurus A so special is the supermassive black hole at its heart which shoots radiation and matter 40,000 light-years across the entire width of the galaxy.

Using the deepest X-ray images ever taken of the galaxy, the researchers found a V-shaped patch of bright emissions caused by the collision of these jets and some unknown object.

NASA says: 'While the researchers have ideas about what is happening, the identity of the object being blasted is a mystery because it is too distant for its details to be seen, even in images from the current most powerful telescopes.'

Scientists have made a baffling discovery as they spot an unknown object being battered by the plasma jet of a supermassive black hole (pictured) 

As black holes gather matter into an accretion disk, some of this is accelerated and shot out into space in the form of a vast beam of plasma and radiation (artist's impression)

When a star more than 20 times the size of our sun dies and explodes in a supernova, the remaining matter collapses down into an extremely dense object called a black hole.

These mysterious voids exert such a strong gravitational force that nothing, not even light, can escape their pull.

As matter and light fall into the black hole like water circling a plug hole, they form an enormous swirling ring called an accretion disk.

However, not all of that matter ends up falling beyond the point of no return known as the event horizon.

Instead, some of the matter gets accelerated along the black holes' powerful magnetic field lines and shot out of the poles and incredible speeds.

While scientists know roughly why these jets form, their near-relativistic speed and intense forces make much of their true nature a mystery.

Located relatively close to Earth, Centaurus A has long been the ideal place to observe these mysterious jets in action.

In previous studies, NASA has spotted a series of 'jet knots' within Centaurus A's massive plumes.

The galaxy Centaurus A (pictured) is 12 million light-years from Earth and is notable for the supermassive black hole at its heart which generated a 40,000-light-year plume of plasma

Scientists have previously spotted 'jet knots) which show up as bright spots of X-ray radiation in images 

Centaurus A: Key Facts

Size: 60,000 light-years in diameter

Mass: 1,000 billion solar masses

Distance from Earth: 12 million light-years

Discovered: 1826 

• • It is notable for its huge belt of dust and the supermassive black hole at its core which produces huge radiation jets. 
  • Centaurus A is the fifth brightest galaxy in the sky which makes it a great target for amateur astronomers.

These are massive areas of turbulence which showed up as bright spots in the X-ray spectrum.

But, in this latest study Dr David Bogensberger, an astrophysicist from the University of Michigan, and his co-authors found a knot which didn't match any of the usual patterns.

Dr Bogensberger and his co-authors write: 'Near the counterjet axis, we detected a source with an unusual morphology. We label it as C4.'

'It appears to have two streams of matter trailing away from it at two distinct angles, forming a ‘V’-like shape behind it.'

The arms of the V are at least about 700 light-years long - 140 times the distance from Earth to the nearest neighbouring star.

The V of strong X-ray radiation traily behind C4 are unusual since all other obstacles in the jet’s path only produce elliptical blobs.

NASA suggests that the mysterious object at the heart of this cosmic wake could be a massive star, either on its own or with a companion star.

The researchers believe that particles in the black hole jet could be colliding with the strong solar winds emitted by this star. 

If this were the case, the resulting turbulence would increase the density of the gas in the jet, igniting the X-ray emission seen within the Chandra images.

However, C4's unique structure raises some problems for this relatively simple explanation.

This study found an object known as C4 which had an unusual V-shaped wake stretching out behind it. This is totally different to the elliptical patterns usually produced by objects caught in a black hole's jet 

Scientists think that C4's unique shape might be the product of a massive star. As particles in the jet collide with solar wind from the star, this compresses the jet and ignites the bright X-ray radiation seen in these images

Read More

• Scientists discover a huge black hole in the Milky Way that's 33 times as massive as the Sun 

If there were an object in the jet, astronomers would expect to see an X-ray trail running roughly parallel to the jet's direction like the wake around a boat moving upstream.

The bottom arm of the V does match this picture, but the top arm is harder to explain since it is at a much larger angle to the jet.

That means, whatever this object is, it may have some very unusual properties which astronomers haven't spotted anywhere else in the universe.  

NASA says: 'Astronomers are trying to determine why C4 has this different post-contact appearance, but it could be related to the type of object that the jet is striking or how directly the jet is striking it.'

However, for now at least, the identity of this strange object will remain stubbornly mysterious.

BLACK HOLES HAVE A GRAVITATIONAL PULL SO STRONG NOT EVEN LIGHT CAN ESCAPE

Black holes are so dense and their gravitational pull is so strong that no form of radiation can escape them - not even light.

They act as intense sources of gravity which hoover up dust and gas around them. Their intense gravitational pull is thought to be what stars in galaxies orbit around.

How they are formed is still poorly understood. Astronomers believe they may form when a large cloud of gas up to 100,000 times bigger than the sun, collapses into a black hole.

Many of these black hole seeds then merge to form much larger supermassive black holes, which are found at the centre of every known massive galaxy.

Alternatively, a supermassive black hole seed could come from a giant star, about 100 times the sun's mass, that ultimately forms into a black hole after it runs out of fuel and collapses.

When these giant stars die, they also go 'supernova', a huge explosion that expels the matter from the outer layers of the star into deep space. 

Black hole blasting powerful jet directly imaged for the first-time ever!

{ https://www.dailymail.co.uk/ }

12-12-2024 om 22:14 geschreven door peter  

Posted by Brian Koberlein

Early Earth's Oceans of Magma Accelerated the Moon's Departure

The Earth and Moon have been locked in a gravitational dance for billions of years. Each day, as the Earth turns, the Moon tugs upon the oceans of the world, causing the rise and fall of tides. As a result, the Earth’s day gets a little bit longer, and the Moon gets a little more distant. The effect is small, but over geologic time it adds up. About 620 million years ago, a day on Earth was only 22 hours long, and the Moon was at least 10,000 km closer than it is now.

Evidence for this evolving dance in the geological record only goes back about two billion years. Beyond that, the Earth was so very different that there simply isn’t enough evidence to gather. So, instead, we must rely on computational models and our understanding of dynamics. We know that when the Earth formed, it had no large moon. Then, about 4.4 billion years ago, a Mars-sized protoplanet named Theia collided with our world to create the Earth-Moon system. What’s interesting is that most of the computer simulations for this collision generate a Moon that is much closer to the Earth than we’d expect. Early Earth didn’t have vast oceans, so there were no water tides to drive the Moon to a larger orbit. So how did the Moon get to its present distance?

A new study argues that back then the Earth did have tides, but they were made of lava, not water. Just after the Great Collision, Earth would have been covered in an ocean of hot lava. With the Moon so near, the lava would have experienced strong tides. Since lava is much denser than water, the effects of the tide would have been much greater. The Earth’s rotation would have slowed down much faster, and the Moon would quickly become more distant. Based on their simulations, the authors argue that the Moon’s distance would have increased by 25 Earth-radii in just 10,000 to 100,000 years. This would explain how the Moon moved towards its present distance range rather quickly.

The idea of tides on an ocean world also has implications for planets around other stars. Planets that form very close to their sun would be extremely hot, and many of them could have lava oceans for a billion years or more. Simulations of such worlds show that lava tides would accelerate the spin dynamics of such a world and could cause them to become tidally locked on a million-year timescale instead of a billion-year timescale. If this model is correct, it would have a significant impact on potentially habitable worlds. Most exoplanets orbit red dwarf stars, since red dwarfs make up about 75% of the stars in our galaxy. The habitable zone of red dwarfs is very close to the star, meaning that many of them would have begun as lava worlds. This would mean most potentially habitable worlds would have one side always facing the sun, while the other side is forever in the cold. Life on these worlds would be very different from what we see on Earth.

How Molten Magma Helped Transform Our Planet | Ancient Earth | BBC Earth Science

The Big Splash - Formation of the Moon

Reference: 

• Farhat, Mohammad, et al. “Tides on Lava Worlds: Application to Close-in Exoplanets and the Early Earth-Moon System.” arXiv preprint arXiv:2412.07285 (2024).

{ https://www.universetoday.com/ }

12-12-2024 om 17:13 geschreven door peter  

Mars Dust Storms Can Engulf The Entire Planet. A New Study Examines How

Today’s weather report on Mars: Windy with a chance of catastrophic dust storms blotting out the sky.

In a new study, planetary scientists at the University of Colorado Boulder have begun to unravel the factors that kick off major dust storms on Mars—weather events that sometimes engulf the entire planet in swirling grit. The team discovered that relatively warm and sunny days may help to trigger them.

Heshani Pieris, lead author of the study, said the findings are a first step toward forecasting extreme weather on Mars, just like scientists do on Earth.

“Dust storms have a significant effect on rovers and landers on Mars, not to mention what will happen during future crewed missions to Mars,” said Pieris, a graduate student at the Laboratory for Atmospheric and Space Physics (LASP) at CU Boulder. “This dust is very light and sticks to everything.”

She will present the results Tuesday, Dec. 10 at the 2024 meeting of the American Geophysical Union in Washington.

To put dust storms under the magnifying glass, the researchers drew on real observations from NASA’s Mars Reconnaissance Orbiter satellite.

So far, they have identified weather patterns that may underly roughly two-thirds of the major dust storms on Mars. You won’t see Mars weather reporters standing in front of a green screen just yet, but it’s a step in the right direction, said study co-author Paul Hayne.

“We need to understand what causes some of the smaller or regional storms to grow into global-scale storms,” said Hayne, a researcher at LASP and associate professor at the Department of Astrophysical and Planetary Sciences. “We don’t even fully understand the basic physics of how dust storms start at the surface.”

This close-up image of a dust storm on Mars was acquired by the Mars Color Imager instrument on NASA’s Mars Reconnaissance Orbiter on Nov. 7, 2007, around 3 p.m. local time on Mars. Scientists working with NASA’s Curiosity rover, which is set to land on Mars on Aug. 5 PDT (Aug. 6 EDT), are monitoring Mars each day for similar small storms that could either drift over the landing site or stir up dust that moves as haze over the site. — NASA (larger image)

Dusty demise

Dust storms on Mars are something to behold.

Many begin as smaller storms that swirl around the ice caps at the planet’s north and south poles, usually during the second half of the Martian year. (A year on Mars lasts 687 Earth days). Those storms can grow at a furious pace, pressing toward the equator until they cover millions of square miles and last for days.

The 2015 film The Martian starring Matt Damon featured one such apocalyptic storm that knocked over a satellite dish and tossed around astronauts. The reality is less cinematic. Mars’ atmosphere is much thinner than Earth’s, so dust storms on the Red Planet can’t generate much force. But they can still be trouble.

In 2018, for example, a global dust storm buried the solar panels on NASA’s Opportunity rover under a layer of dust. The rover died not long after.

“Even though the wind pressure may not be enough to knock over equipment, these dust grains can build up a lot of speed and pelt astronauts and their equipment,” Hayne said.

Hot spells

In the current study, Pieris and Hayne set their sights on two weather patterns that tend to occur every year on Mars known as “A” and “C” storms.

The team pored over observations of Mars from the Mars Climate Sounder instrument aboard the Mars Reconnaissance Orbiter over eight Mars years (15 years on Earth). In particular, Pieris and Hayne looked for periods of unusual warmth—or weeks when more sunlight filtered through Mars’ thin atmosphere and baked the planet’s surface.

They discovered that roughly 68% of major storms on the planet were preceded by a sharp rise in temperatures at the surface. In other words, the planet heated up, then a few weeks later, conditions got dusty.

“It’s almost like Mars has to wait for the air to get clear enough to form a major dust storm,” Hayne said.

The team can’t prove that those balmy conditions actually cause the dust storms. But, Pieris said, similar phenomena trigger storms on Earth. During hot summers in Boulder, Colorado, for example, warm air near the ground can rise through the atmosphere, often forming those towering, gray clouds that signal rain.

“When you heat up the surface, the layer of atmosphere right above it becomes buoyant, and it can rise, taking dust with it,” Pieris said.

She and Hayne are now gathering observations from more recent years on Mars to continue to explore these explosive weather patterns. Eventually, they’d like to get to the point where they can look at live data coming from the Red Planet and predict what could happen in the weeks ahead.

“This study is not the end all be all of predicting storms on Mars,” Pieris said. “But we hope it’s a step in the right direction.”

VIDEOS

{ https://astrobiology.com/ }

11-12-2024 om 22:16 geschreven door peter  

Five UFO videos this week, are they alien, ai US drones or Chinese ai drones? UAP Sighting News.

Here are the top 5 most interesting videos of UFOs this week. Each are different, some with swarms, so watch and decide what is happening and can you predict the future outcomes of this? 

Scott C. Waring 

Full credit to NUFORC for reports at  https://nuforc.org/

I believe I may have discovered the purpose of the swarms of drones, God help us if I'm right. US Drone News.

Now I heard the swarms of drones were seen over Trumps favorite golf course for over three days and nights which makes me think...why? Who hates trump the most outside of the US? Easily one country over all does...the county he promised to put 25% taxes on all goods going out of China to US, and I believe the Chinese are behind these swarms. They must be radar resistant, which means they are plastic or 3d printed with some rubber radar resistant coating to absorb radar. They were seen over England, New York, Michigan, New Jersey and a few other locations. Read the tweet and tell me...am I wrong? Or...worse yet...am I right? If I'm right the virus could be waiting for a second drone spraying to become the catalyst of the virus, or the virus could have a built in genetic time to go off in 1 week, 1 month or even 1 years time. By then...everyone will forget about the drones. Because of a genetic timer, we cannot blame the drones, much like HAARP program that manipulates the weather and China uses it making it impossible to blame then on earthquakes (Japan-Chinas worst enemy at Fukushima), tidal waves, tornadoes, hurricanes and more. And China causes tens of billions of dollars in damage on such untraceable attacks. Ask yourself, what are the Chinese up to now? 

at 12/10/2024 01:56:00 PM 

{ https://www.ufosightingsdaily.com/ }

11-12-2024 om 18:41 geschreven door peter  

The orbits of the planets around the Sun have been the source for many a scientific debate. Their current orbital properties are well understood but the planetary orbits have evolved and changed since the formation of the Solar System. Planetary migrations have been the most prominent idea of recent decades suggesting that planetary interactions caused the young planets to migrate inwards or outwards from their original positions. Now a new theory suggests 2-50 Jupiter mass object passing through the Solar System could be the cause. 

The evolution of the orbits of the planets is a complex process. Initially the planets formed out of a rotating disk of gas and dust around the young hot Sun. The phenomenon of the conservation of angular momentum caused the material to form a plane leading to orbits that were circular and in the same plane. 

As the planets grew, interactions within the protoplanetary disk led to orbital migrations with planets moving inwards or outwards. There were gravitational interactions too that led to significant changes in the eccentricity and inclination, sometimes causing protoplanets to be ejected out of the solar system. Tidal forces from the Sun could also have altered the orbits. 

While protoplanet ejections are thought to have been fairly common as the Solar System was forming, on occasions celestial objects visited us. These objects seem to have been rare and provide a valuable insight into distant planetary systems. Oumuamua, was discovered in 2017 and was the first confirmed interstellar visitor. It exhibited an elongated shape and unusual acceleration, probably caused by outgassing or other non-gravitational forces. A paper recently published has suggested such an interstellar visitor could have driven changes in the orbits of our planetary cousins. 

The paper was authored by a team of scientists led by Garett Brown University of Toronto. They explore the nature of the eccentricity of the gas giants suggesting it is unlikely the current theories can explain observations. Instead they demonstrate that an object with between 2 to 50 times the mass of Jupiter passing through the Solar System was a more likely cause. Their paper explains that an object passing through with a perihelion distance (closest distance from Sun) of less than 20 astronomical units and a hyperbolic excess velocity less than 6km/s-¹ could explain observations.  

Their calculations suggest there is a 1 in 100 chance that an interstellar visitor could produce the orbits we see today, chances that are far better than other theories. Using simulations and approximate values for the properties of the visitor, the team conclude that the theory is the most plausible to date. 

Source :

• A substellar flyby that shaped the orbits of the giant planets

{ https://www.universetoday.com/ }

11-12-2024 om 18:20 geschreven door peter  

NASA's most powerful telescope detects something unexpected happening to the universe

• READ MORE: First breathtaking images from Euclid's 'cosmic atlas' are revealed

By WILIAM HUNTER

NASA's most powerful telescope has spotted something unexpected which could overturn our basic assumptions about the universe.

Using the James Webb Space Telescope (JWST), scientists from Johns Hopkins University have taken extremely accurate measurements of the distances between galaxies.

These observations reveal that the universe is expanding eight to 12 per cent faster than our current best theories predict.

This suggests that there may be some unknown force which explains why the universe is expanding faster now than it was billions of years ago.

First spotted by the Hubble Space Telescope in 1998, it was previously possible that this acceleration was caused by nothing more unusual than a telescope error.

However, using two years of JWST observations, the researchers have now shown that Hubble's shocking findings were not mistaken.

According to lead author and Nobel laureate Professor Adam Riess, this shows that our understanding of the birth of the universe could be totally wrong.

He says: 'It confirms the puzzling finding from the Hubble Space Telescope that we have been wrestling with for a decade - the universe is now expanding faster than our best theories can explain.'

Scientists have used the James Webb Space Telescope to confirm that the Universe really is accelerating up to 12 per cent faster than our best theories would suggest. Illustrated: the expansion of the Universe from the Big Bang (left) to the present day (right)

Scientists measured the distance between distant galaxies containing pulsing stars called Cepheid variables. Since these flash at a rate proportional to their brightness, they are considered the 'gold standard' for measuring interstellar distances. Pictured: NGC 5468, a galaxy located about 130 million light-years from Earth which is the furthest galaxy observed to contain Cepheid variables 

Professor Riess initially used the Hubble Space Telescope to measure the distance between a set of different galaxies.

This revealed that the Universe's expansion was accelerating at a rate of 72.8 km per second per megaparsec, a distance equal to 3.26 million light-years.

What made this result so surprising is that the conventional wisdom about the evolution of the Universe suggested this figure should only be 67-68 km/s/Mpc.

This had the shocking implication that the standard model of cosmology might be missing out on something vitally important, creating what astronomers call the 'Hubble tension'.

More than 25 years later, Professor Riess has now used NASA's biggest and highest-performing telescope to prove that his Nobel Prize-winning discovery had not been an error.

Using the JWST Reiss and his co-authors focussed on a set of galaxies containing pulsing stars called Cepheid variables.

These unique stars flash at a rate which is proportional to their brightness, or luminosity, which makes them the 'gold standard' for measuring interstellar distances.

Using the well-studied galaxy NGC 4258 as a reference point, the study covered a third of the Hubble Telescope's original galaxy sample.

The new study covered roughly a third of Hubble's full galaxy sample, using the known distance to a galaxy called NGC 4258 (pictured) as a reference point. This allowed for extremely accurate measurements of the distance between galaxies 

The first observations made by Hubble in 1998 showed that the galaxy's expansion was accelerating faster than the standard model would suggest. The standard model is the theory which explains the Big Bang, the cosmic microwave background (pictured), and the early formation of galaxies

What is the standard model of cosmology?

The standard model of cosmology is the conventional wisdom about the underlying physics of the universe.

Often called the Lambda-CDM theory, this suggests the universe has three major components: matter, dark matter, and dark energy.

This explains the existence and pattern of the cosmic microwave background, the lingering echo of the Big Bang, and the distribution of galaxies.

However, it doesn't align with new observations of the Universe's rapidly accelerating expansion.  

Although the sample size was smaller, the team managed to take measurements about four times as precise as the previous study.

In addition to Cepheid variables, the researchers also took measurements from carbon-rich stars and the brightest red supergiants across the same galaxies.

This allowed them to further cross-check their results to be absolutely certain their measurements were correct.  

Spiral galaxy NGC 628, located 32 million light-years away from Earth, is seen in an undated image from the James Webb Space Telescope. NASA, ESA, CSA, STScI, Janice Lee (STScI), Thomas Williams (Oxford), and the PHANGS team/Handout via REUTERS/File Photo Purchase Licensing Rights

These new recordings revealed that the galaxies were accelerating away from each other at a rate of 72.6 km/s/Mpc - nearly identical to Hubble's measurements from the very same galaxies.

Professor Riess says: 'The discrepancy between the observed expansion rate of the universe and the predictions of the standard model suggests that our understanding of the universe may be incomplete.

'With two NASA flagship telescopes now confirming each other’s findings, we must take this [Hubble tension] problem very seriously—it’s a challenge but also an incredible opportunity to learn more about our universe.'

This implies that we might be missing something vitally important about the birth of the universe.

Siyang Li, a Johns Hopkins doctoral student and a study co-author says: 'The Webb results can be interpreted to suggest there may be a need to revise our model of the universe, although it is very difficult to pinpoint what this is at the moment.'

By measuring the same set of galaxies as Hubble (illustrated), the scientists confirmed that the universe was accelerating at a rate of 72.6 km per second per megaparsec, a distance equal to 3.26 million light-years. The standard model suggests an acceleration of just 67-68 km/s/Mpc 

The standard model explains the evolution of galaxies, the cosmic microwave background from the Big Bang, the abundance of chemical elements in the universe, and many other key observations based on the known laws of physics.

However, nothing that scientists have been able to observe explains why the Universe should be accelerating at such a rapid rate.

Scientists believe the regular matter we can see and interact with makes up just 4 per cent of the total universe.

The remaining 96 per cent of the universe is made up of dark matter, which makes up the missing mass in some galaxies, and dark energy.

Dark energy could make up as much as 69 per cent of the universe and might provide the force responsible for space's expansion.

However, with the nature of dark energy remaining a mystery, scientists are still no closer to resolving the Hubble tension than they were back in 1998.

Professor Reiss says: 'Yes, it appears there is something missing in our understanding of the universe.

'Our understanding of the universe contains a lot of ignorance about two elements - dark matter and dark energy.

'There are many hypotheses that involve dark matter, dark energy, dark radiation - for example, neutrinos (a type of ghostly subatomic particle) - or gravity itself having some exotic properties as possible explanations.'

In the future, Professor Reiss says scientists will need more observations to better understand this vital clue. 

Eventually, that might help scientists propose a theory which explains why our predictions and observations about the universe don't line up.

He adds: 'Is the mismatch at the lower end, four to five per cent, or the higher end, 10 to 12 per cent, of what the current data allows? Over what range of cosmic time is it present? These will further inform ideas.'

WHAT IS DARK ENERGY?

Dark energy is a phrase used by physicists to describe a mysterious 'something' that is causing unusual things to happen in the universe. 

The universe is full of matter and the attractive force of gravity pulls all matter together. 

Then came 1998 and the Hubble Space Telescope observations of very distant supernovae that showed that, a long time ago, the universe was actually expanding more slowly than it is today.

The universe is not only expanding, but it is expanding faster and faster as time goes by,' Dr Kathy Romer, scientist at the Dark Energy Survey told MailOnline, as illustrated in this Nasa graphic

So the expansion of the universe has not been slowing due to gravity, as everyone thought, it has been accelerating. 

No one expected this, no one knew how to explain it. But something was causing it.

'The universe is not only expanding, but it is expanding faster and faster as time goes by,' Dr Kathy Romer, scientist at the Dark Energy Survey told MailOnline.

'What we'd expect is that the expansion would get slower and slower as time goes by, because it has been nearly 14 billion years since the Big Bang.'

This illustration depicts NASA’s James Webb Space Telescope – the largest, most powerful, and most complex space science telescope ever built – fully unfolded in space.

(Credits: NASA/Adriana Manrique Gutierrez)

Depiction of Hubble Telescope in bright outer space. Elements of this image furnished by NASA.

(© dimazel – stock.adobe.com)

{ https://www.dailymail.co.uk/ }

10-12-2024 om 22:01 geschreven door peter  

Reuzenkaart van het heelal onthult: Einstein had weer gelijk

Door de donkere energie van het heelal in kaart te brengen, hebben astronomen een gigantische kaart gemaakt die een van Einsteins beroemdste theorieën aan de zwaarste test tot nu toe onderwerpt.

Een van de beroemdste theorieën van Albert Einstein is de algemene relativiteitstheorie uit 1915.

De theorie beschrijft hoe massieve objecten ruimte en tijd om zich heen krommen, wat weer invloed heeft op hoe objecten bewegen. Met andere woorden, ze vertelt ons iets over zwaartekracht.

De theorie wordt echter voortdurend op de proef gesteld.

Astrofysici hebben bijvoorbeeld verklaringen moeten vinden voor het feit dat het heelal steeds sneller uitdijt terwijl massieve objecten samenklonteren door de zwaartekracht.

Nu heeft de zwaartekrachttheorie haar grootste test tot nu toe doorstaan.

Een internationaal team van onderzoekers aan onder andere de Universiteit van Michigan en de Universiteit van Texas in de VS heeft gegevens geanalyseerd van het ruimteobservatorium Dark Energy Spectroscopic Instrument (DESI) in Arizona.

Het instrument bestaat uit 5000 robotjes die samen met een reeks lichtmeters terug kunnen kijken in de geschiedenis van het heelal door donkere energie te onderzoeken en de afstand tot miljoenen sterrenstelsels en quasars in kaart te brengen.

Einsteins theorie houdt stand

Met de huidige gegevens heeft het onderzoeksteam de verspreiding, groei en ontwikkeling van meer dan 5,7 miljoen sterrenstelsels in kaart gebracht over een periode van 11 miljard jaar – van de totale ouderdom van het heelal van 13,8 miljard jaar.

Volgens astronomen is het heelal georganiseerd in het zogeheten kosmische web.

Hier zijn sterrenstelsels en clusters van sterrenstelsels verdeeld in een netwerk van lange strengen van donkere materie en sterrenstelsels, zogeheten filamenten, waar bijna geen sterrenstelsels zijn.

In het kosmische web vormt donkere materie ongeveer 27 procent van de totale energie van het heelal, terwijl donkere energie, die ervoor zorgt dat het heelal uitdijt en in principe de zwaartekracht tegenwerkt, ongeveer 68 procent vormt.

Het onderzoeksteam gebruikte de algemene relativiteitstheorie om de groei van het kosmische web te voorspellen.

Ze zagen dat de manier waarop de zwaartekracht de sterrenstelsels samenklontert en de manier waarop het kosmische web zich in de loop van de tijd ontwikkelt, consistent is met de theorie van Einstein.

Als er zwaartekracht aan de vergelijking zou worden toegevoegd of eruit zou worden verwijderd, zou het heelal er niet zo uitzien als nu.

De resultaten verklaren ook een ontdekking van het DESI-instrument in april 2024.

Hierbij observeerden wetenschappers dat donkere energie in de loop van de tijd verandert en dat het heelal daarom niet statisch uitdijt.

Er waren zelfs aanwijzingen dat het effect van donkere energie afnam. Dit zou verband kunnen houden met zwaartekracht.

Een extra bevinding

Het huidige onderzoek wierp ook nieuw licht op een ander kosmisch mysterie: het neutrino.

Neutrino’s zijn een soort elementaire deeltjes die nogal ongrijpbaar zijn, omdat ze geen elektrische lading hebben en bijna geen massa. Daarom worden ze ook wel spookdeeltjes genoemd.

Eerder onderzoek heeft een ondergrens gevonden voor de massa van neutrino’s. Met de nieuwe DESI-gegevens konden onderzoekers de bovengrens van de massa van neutrino’s bepalen.

{ https://wibnet.nl/heelal }

10-12-2024 om 20:31 geschreven door peter  

Venus Has Never Been Habitable, New Study Suggests

Planetary researcher Tereza Constantinou and her colleagues at the University of Cambridge have examined the chemical composition of the Venusian atmosphere and inferred that the planet’s interior is too dry today for there ever to have been enough water for oceans to exist at its surface; instead, Venus has likely been a scorching, inhospitable world for its entire history.

This composite image, taken by JAXA’s Akatsuki spacecraft, shows Venus.

Image credit: JAXA / ISAS / DARTS / Damia Bouic.

From a distance, Venus and Earth look like siblings: it is almost identical in size and is a rocky planet like Earth.

But up close, Venus is more like an evil twin: it is covered with thick clouds of sulfuric acid, and its surface has a mean temperature close to 500 degrees Celsius.

Despite these extreme conditions, for decades, astronomers have been investigating whether Venus once had liquid oceans capable of supporting life, or whether some mysterious form of ‘aerial’ life exists in its thick clouds now.

“We won’t know for sure whether Venus can or did support life until we send probes at the end of this decade,” Constantinou said.

“But given it likely never had oceans, it is hard to imagine Venus ever having supported Earth-like life, which requires liquid water.”

When searching for life elsewhere in our galaxy, astronomers focus on planets orbiting their host stars in the habitable zone, where temperatures are such that liquid water can exist on the planet’s surface.

Venus provides a powerful limit on where this habitable zone lies around a star.

“Even though it’s the closest planet to us, Venus is important for exoplanet science, because it gives us a unique opportunity to explore a planet that evolved very differently to ours, right at the edge of the habitable zone,” Constantinou said.

The dichotomous climate pathways proposed for Venus.

Image credit: Constantinou et al., doi: 10.1038/s41550-024-02414-5.

There are two primary theories on how conditions on Venus may have evolved since its formation 4.6 billion years ago.

The first is that conditions on the surface of Venus were once temperate enough to support liquid water, but a runaway greenhouse effect caused by widespread volcanic activity caused the planet to get hotter and hotter.

The second theory is that Venus was born hot, and liquid water has never been able to condense at the surface.

“Both of those theories are based on climate models, but we wanted to take a different approach based on observations of Venus’ current atmospheric chemistry,” Constantinou said.

“To keep the Venusian atmosphere stable, then any chemicals being removed from the atmosphere should also be getting restored to it, since the planet’s interior and exterior are in constant chemical communication with one another.”

The researchers calculated the present destruction rate of water, carbon dioxide and carbonyl sulfide molecules in Venus’ atmosphere, which must be restored by volcanic gases to keep the atmosphere stable.

Volcanism, through its supply of gases to the atmosphere, provides a window into the interior of rocky planets like Venus.

As magma rises from the mantle to the surface, it releases gases from the deeper portions of the planet.

On Earth, volcanic eruptions are mostly steam, due to our planet’s water-rich interior.

But, based on the composition of the volcanic gases necessary to sustain the Venusian atmosphere, the scientists found that volcanic gases on Venus are at most six percent water.

These dry eruptions suggest that Venus’s interior, the source of the magma that releases volcanic gases, is also dehydrated.

At the end of this decade, NASA’s DAVINCI mission will be able to test and confirm whether Venus has always been a dry, inhospitable planet, with a series of flybys and a probe sent to the surface.

The results could help astronomers narrow their focus when searching for planets that can support life in orbit around other stars in the galaxy.

“If Venus was habitable in the past, it would mean other planets we have already found might also be habitable,” Constantinou said.

“Instruments like the NASA/ESA/CSA James Webb Space Telescope are best at studying the atmospheres of planets close to their host star, like Venus.”

“But if Venus was never habitable, then it makes Venus-like planets elsewhere less likely candidates for habitable conditions or life.

“We would have loved to find that Venus was once a planet much closer to our own, so it’s kind of sad in a way to find out that it wasn’t, but ultimately it’s more useful to focus the search on planets that are mostly likely to be able to support life — at least life as we know it.”

• The study was published this month in the journal Nature Astronomy.
• T. Constantinou et al. A dry Venusian interior constrained by atmospheric chemistry. Nat Astron, published online December 2, 2024; doi: 10.1038/s41550-024-02414-5
• This article is based on a press-release provided by the University of Cambridge.

{ https://www.sci.news/ }

09-12-2024 om 20:45 geschreven door peter  

EXCLUSIVE - I'm a professional asteroid hunter - and this is what NASA is not telling you about the space rocks on a collision course for Earth

• READ MORE: Incredible moment asteroid crashes into Earth's atmosphere

By WILIAM HUNTER

This week, an asteroid slammed into Earth's atmosphere and exploded in a ball of fire above Siberia.

From the time the space rock was spotted by NASA to the time it hit Earth, space agencies around the world had just seven hours to react.

Luckily for Earth, this asteroid was only 70cm across and burned up harmlessly in the air - but for asteroid hunter Franck Marchis, this was too close for comfort.

Dr Marchis, senior astronomer at the SETI Institute and founder of the UNISTELLAR citizen astronomer network, told MailOnline: 'If it had been slightly bigger, that would been a very different story.'

While institutes like NASA and the European Space Agency (ESA) keep a close watch for any space rocks that threaten Earth, there simply aren't enough people watching the sky to catch everything. 

If scientists want to save humanity from a potential 'city killer' asteroid we need years of warning, not a handful of hours.

The solution, according to Dr Marchis, is to enlist amateur astronomers to fill in the gaps left behind by the professionals.

Dr Marchis says: 'Asteroids can come at any moment towards Earth. Having eyes on the sky everywhere in the world allows us to track them.' 

Professional asteroid hunter Franck Marchis says that governmental space agencies like NASA and ESA can't protect Earth from an impending asteroid impact alone

Franck Marchis (pictured) senior astronomer at the SETI Institute and founder of UNISTELLAR, told MailOnline that the only way to protect Earth from asteroids is for civilians to spot the threats that NASA misses 

What's the risk of an asteroid hitting Earth? 

On Christmas Day, 2004, while most of us were busy opening presents and enjoying time with our families, Dr Marchis was facing down a potentially deadly threat.

NASA had spotted a large space rock, known as a Near-Earth Object (NEO), and sent out a call for astronomers to take a closer look. 

After taking measurements of the asteroid's course and calculating its orbit, Dr Marchis and other astronomers came to the sobering realisation that it was headed right for Earth.

At around 400m in diameter, the asteroid, known as 2004 MN4, was a true city killer capable of punching through the atmosphere and hitting the planet with devastating force.

To make matters worse, Dr Marchis predicted that there were only four to seven hours before impact.

He says: 'The community was freaked out, for several hours we had no idea if it was going to hit the planet or not.'

Thankfully, it turned out that the initial observations had been wrong and 2004 MN4 merely skimmed by the planet without colliding.

Just like the film 'Don't Look Up', on Christmas Day 2004, Dr Marchis detected an asteroid that was predicted to collide with Earth. However, unlike the film, Dr Marchis spotted the 400m-long space rock when there were only four hours before it was expected to hit 

However, for seven hours on Christmas Day, there were only about 400 people in the world who knew just how close Earth had come to total disaster.

He says: 'I think when you see something like that, you realise that this is possible and you realise the potential impact of it.'

Each day, the Earth is bombarded by an estimated 100 tonnes of material from space, most of which are no larger than a grain of dust and burn up harmlessly in Earth's atmosphere.

However, astronomers have discovered 36,765 NEOs, including more than 11,000 which are over 140m across and 868 larger than a kilometre.

Of those, 1,714 are on the 'risk list' meaning that there is a non-zero chance of a collision with Earth. 

With space around Earth so full of potential threats, near misses are not entirely uncommon.

Last year a 130m-wide space rock named 2019 OK travelling at 88,500 kmph (55,000 mph) passed within just 72,500 km (45,000 miles) of Earth - extraordinarily close in astronomical terms.

Nor do asteroids need to be as large as 2003 MN4 to cause absolute devastation.

In 2004, Dr Marchis detected the asteroid 400m-wide 2004 MN4. At the time, calculations suggested it may hit Earth within hours of its discovery 

The Chelyabinsk meteor (pictured) which injured over 1,600 and damaged over 7,000 buildings in 2013 was believed to be just 18m in diameter.

For instance, the Chelyabinsk meteor which injured over 1,600 and damaged over 7,000 buildings in 2013 was believed to be just 18m in diameter.

Dr Marchis says: 'An asteroid of over 120 metres will impact our planet every 10,000 years on average.

'This shows that, if we want our civilisation to last for a long period of time, we need to look around us and characterise those objects.'

How can we save Earth from a devastating asteroid impact?

After the Christmas Day scare, Dr Marchis says he realised that small groups of professionals simply weren't up to the task of defending the entire planet.

'There are multiple stations around the world, professional telescopes, that detect and characterise objects but most of them are located in the same area,' Dr Marchis says. 

'It means that if an asteroid is coming to us from over Japan or Russia there is nobody looking in this direction, so we still have what we call dark zones.'

The novel solution was that, instead of having a handful of massive advanced systems, you could fill the dark zones with small, cheap telescopes to watch the whole sky at once.

Dr Marchis' initial plan was to place a series of small satellite telescopes in orbit (pictured) to detect incoming asteroids. However, this was deemed too expensive 

Dr Marchis says: 'We quickly realised that having an entire worldwide array of telescopes capable of watching all of the sky all of the time would help.'

Back in 2014, Dr Marchis thought that the best way to do this would be to surround the planet with a network of orbiting telescope satellites.

However, before the days of reusable rockets, nobody was interested in funding a vast satellite constellation and Dr Marchis now calls the idea his 'sci-fi' project.

Unable to put his telescopes in space, Dr Marchis ultimately settled on the next best thing: putting them in as many homes around the world as physically possible.

In 2015, he founded UNISTELLAR which makes relatively cheap telescopes 'smart telescopes' which can track objects in space and share their measurements with a network of amateur astronomers.

These observations allow average civilians to light up the world's dark zones and keep a watchful eye on anything that could pose a threat to Earth.  

When NASA or ESA's wide-angle telescopes spot something bright and fast moving through the sky they send a notification to a database called the Minor Planets Centre.

Dr Marchis says: 'Based on about five or six observations they tell other people: "Hey, there is an asteroid coming to us and it could be potentially hazardous."

Instead of going to space, Dr Marchis founded Unistellar which sells telescopes (pictured) that automatically share data on the objects they observe with a network of amateur astronomers. This allows scientists to gather lots of observations of potentially hazardous objects

'Amateur astronomers including those in our network get this notification and use our telescopes to refine the observation.

'It's by combining all those eyes together that refines the predicted orbit of the asteroid and confirms whether it is an asteroid rather than a piece of rocket.'

In the case of spotting a dangerous asteroid, the impact will first be confirmed by NASA's Sentry and ESA's Meerkat prediction systems.

Then Dr Marchis and the other members of UNISTELLAR would bring their predictions to the UN's International Asteroid Warning Network to coordinate the response.

This was exactly what happened with the asteroid COWECP5 which dramatically exploded over Russia this week.

The asteroid was spotted by a NASA-funded telescope in Arizona about seven hours prior to impact.

Amateur astronomers in Japan and Australia then used their smaller telescopes to work out exactly where and when it would hit.

This time, it was determined that the space rock would burn up in the atmosphere so the issue was not escalated to the UN but, if it had been bigger, it would have been these citizen scientists' observations which determined the areas to be evacuated. 

The Earth frequently faces near misses from hazardous asteroids. This year four 'potentially hazardous' asteroids passed Earth within a 12-hour window. The largest was the 'city killer' asteroid 2002 NV16 which is taller than the Blackpool Tower 

The future of planetary defence 

However, if humanity is to survive into the future, we need to do more than just know when Earth is about to be hit by an asteroid - we need a way of stopping it.

'The good news is that, two years ago, we made an experiment showing that we can deflect an asteroid if we know well in advance that such an impact will happen,' Dr Marchis says.

'And that's changing a lot about how we think about this problem.'

The experiment Dr Marchis refers to is NASA's Double Asteroid Redirection Test (DART) which slammed a fast-moving satellite into the side of a distant asteroid.

Although the results will be confirmed in 2026 by ESA's Hera mission, the early results show that the asteroid was indeed bumped out of its orbit.

And, as the satellite collided with its target, it was telescopes in the UNISTELLAR network that recorded the impact as it happened.

These observations provided the first images of the plumes of dust and debris caused by the collision which showed that the $324.5 million (£253.5 million) mission had been a success.

NASA's DART mission used a small fast-moving satellite to slam into a massive asteroid. This test showed that it is possible to knock an asteroid out of a collision course with Earth 

It was even the hard work of citizen scientists which provided the data that proved humanity really could push a dangerous asteroid out of the way.

Dr Marchis says that the goal is now to expand the UNISTELLAR network so that amateur astronomers can start to identify any asteroids that could pose a threat.

He says: 'What we need to do is map the entire surroundings of Earth to find all those bodies 120m or larger because, as soon as we know that one of them could impact our planet, we just have to send a spacecraft over to deflect it.

'We do more observations in a year now than we have done over the past 200 years but we could still do better.'

For example, there are still vast dark zones over the developing countries where Earth just can't see what is coming its way.

Dr Marchis says that the only solution is to either 'win the lottery' to fund his satellite telescopes or get more amateur astronomers involved in planetary defence.

He concludes: 'If people like astronomy or if they want to do something more meaningful in their life they should really look at what we do in citizen science.

'This is a movement which is going to change the way we progress as a civilisation and UNISTELLAR is proof that every human can make remarkable discoveries that will one day change humanity.'

{ https://www.dailymail.co.uk/ }

08-12-2024 om 23:26 geschreven door peter  

The Artemis moon landings are delayed again due to technical difficulties. This time, the problem is with the Orion spacecraft heat shield. NASA administrator Bill Nelson announced that the new landing dates are in April of 2026 for Artemis II and sometime in 2027 for the first human landing during the Artemis III mission.

The difficulties the Artemis program faces stem from the complexity of the hardware and trajectories needed to take astronauts to the Moon according to Nelson. “The Artemis campaign is the most daring, technically challenging, collaborative, international endeavor humanity has ever set out to do,” said Nelson. He pointed out that the mission has made a lot of progress. However, there’s more work to be done, in particular on the Orion life support systems. Artemis II is next up in early 2026. It will be a test flight to demonstrate the viability of all the systems, said Nelson. “We need to get this next test flight right. That’s how the Artemis campaign succeeds.”

Making a safe return through Earth’s atmosphere is a vital part of the mission. After Orion came back from its Artemis 1 mission in November 2022, engineers noticed issues with the heat shield. They figured out that gases generated inside the heat shield didn’t vent properly. That caused cracks in the shield and triggered an investigation. The decision to delay the Artemis II test flight came after that investigation. This allows NASA engineers to work with the heat shield currently attached to the Orion capsule for the April 2026 flight. In addition, they’re studying the re-entry process to avoid future problems with the shield. 

Artemis II to the Moon

As we all know, the Artemis program will allow long-term exploration of the Moon. The April 2026 mission is a test flight that will orbit, but not land, and then return to Earth. The idea is to test all the spacecraft’s systems with astronauts on board.

The Orion spacecraft is the crew’s living quarters and lab, all in one. It’s built to carry four astronauts from Earth to space and ultimately to the Moon. It makes sense that this “home away from home” has to be shielded from pretty much anything that space—and Earth’s atmosphere—can throw at the capsule. This includes the ultrahot trip through our atmosphere on the return trip. At times, Orion experiences temperatures up to 2700 C (5000 F), which could harm the capsule if not for the shielding. So, the shield is a life-saver.

When Orion first encountered the heat shield problem, engineers determined that heating rates increased during the spaceship’s planned “dips” into the atmosphere. It was performing a skip guidance entry technique. Heat built up inside the heat shield’s material and gases accumulated. Eventually, that cracked areas in the outer layer of the shield and blew some of it off to space. It turns out that if astronauts had been aboard, they would not have been affected. However, now that engineers understand what occurred, they can enhance the heat shield material to make sure it doesn’t happen again. In addition, the mission plan will be altered to change how far the capsule flies between atmospheric re-entry and eventual landing.

Upgrading Mission Plans

The extended time until the April 2026 and mid-2027 Artemis missions will allow improvements to the capsule and launch systems. For example, engineers can give more attention to environmental and life support systems. This is particularly important for the Artemis III mission. It will launch on top of a Space Launch System rocket into Earth orbit. Once there, the mission will perform a translunar injection to send it to lunar space.

Not only will it carry astronauts to the Moon, but they will land in the south polar region using a SpaceX landing system. That 30-day mission will require at least two crew members to spend a week at the pole collecting samples, doing site photography, and measuring conditions there.

Artemis III will be the first time anyone has set foot on the Moon since the last Apollo mission in December 1972. The entire Artemis program aims at providing long-term habitation and study of Earth’s nearest neighbor in space. To that end, NASA has been studying several interesting landing spots at the pole.

Eventually, there will be an orbiting lunar station, plus habitats on the surface and regular trips between. NASA and other agencies expect that lunar explorers will be spending their time studying the surface and geology of the Moon, plus determining what resources are available for long-term exploration and habitation. However, given the pace of the program, those next developments probably won’t take place until the 2030s.

For More Information

• NASA Identifies Cause of Artemis I Orion Heat Shield Chart Loss
• As Artemis Moves Forward, NASA Picks SpaceX to Land Next Americans on Moon
  Artemis II
• Artemis III: NASA’s First Human Mission to the Lunar South Pole

{ https://www.universetoday.com/ }

07-12-2024 om 23:28 geschreven door peter