Planetary Scientists Create Geological Map of Moon’s Oriental Basin

Researchers at the Planetary Science Institute have compiled a 1:200,000-scale geological map of the lunar Orientale basin, focusing on identifying the most widespread and accessible occurrences of impact melt deposits from the basin-forming impact to help guide sample-return missions.

1:3M mapping (originally mapped at 1:200,000) of a portion of the Orientale basin. The small craters near ‘Pa’ (red and yellow stars) excavate Orientale melt from beneath the mare and serve as a useful type example for similar small craters in similar basins. Maunder, the large crater in the NW part of the map, is Eratosthenian in age.

Image credit: Runyon et al., doi: 10.3847/PSJ/ad862f.

Billions of years ago, a giant asteroid struck the Moon with so much energy that it melted rock until it was super-heated and white-hot, or what scientists call impact melt.

This eventually cooled and hardened, creating a multi-ringed impact crater that is known today as Orientale basin.

Having samples of impact melt is valuable because scientists can use laboratory techniques to determine the exact time of the melt’s solidification, and therefore the age of the impact.

The problem is, geologic processes after impact — such as lava flows and smaller impacts — have buried and mixed up much of the original impact melt.

But parsing out the impact crater from which a rock originated is worth the effort because that knowledge can help scientists understand how the impact rate changed throughout the Solar System’s history, as well as how impacts shaped the Moon, the Earth and early life on our planet.

To identify original basin impact melt, Planetary Science Institute researcher Kirby Runyon and colleagues created a new high-resolution geologic map of the Orientale basin.

“We chose to map Oriental basin because it’s simultaneously old and young,” Dr. Runyon said.

“We think it’s about 3.8 billion years old, which is young enough to still have its impact melt freshly exposed at the surface, yet old enough to have accumulated large impact craters on top of it as well, complicating the picture.”

The Moon’s Orientale basin is a massive lunar crater that looks like a bullseye and is about the size of Texas.
Credit: NASA Goddard Space Flight Center.

“We chose to map Orientale to test melt-identification strategies for older, more degraded impact basins whose ages we’d like to know.”

The scientists used BFsc — shorthand for smooth, cracked basin floor material — to map original, unpolluted impact melt from the Orientale basin’s formation.

Those rocks record the age of the basin, and parts of this melt deposit would have been buried beneath other geologic units, such as the lava flows mapped in red.

Stars mark rims and debris from smaller impact craters that have unearthed previously buried Orientale melt.

So, if rocks from starred locations turn out to be the same age as rocks from the BFsc areas, geologists know they can rely on rocks from similar small craters on other, more degraded basins to record the ages of those basins’ formation.

“We hope that our mapping method can be used in other impact basins across the Moon so that future sample return missions could test this approach by sampling rocks from areas similar to those highlighted on the map,” the authors said.

“If samples collected from any of the starred areas on our map are the same age as samples collected from the BFsc areas that denote original impact melt, then we have confidence that we can apply the impact melt sampling technique to other basins.”

The team’s map appears in a paper published in the Planetary Science Journal.

• Kirby Runyon et al. 2024. Orientale Basin as a Guide for Identifying Lunar Basin Datable Impact Melt and Assessing Impact Melt Differentiation. Planet. Sci. J 5 (11): 249; doi: 10.3847/PSJ/ad862f
• This article is a version of a press-release provided by the Planetary Science Institute.

{ https://www.sci.news/ }

20-11-2024 om 23:07 geschreven door peter  

A sample of the Moon’s far side retrieved by Chang’e-6 contains 2.83-billion-year-old basalt

Abstract

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Radioisotope dating

The thirty-three low-Ti basaltic clasts were used for Pb isotope measurements (data S3). Zr-bearing minerals (number of analyses n = 44), apatite (n = 78), potassium (K)-rich phases (K-feldspar, K-glass, n = 54) and troilite (n = 11) were analyzed in a secondary ion mass spectrometer using a primary beam of O^- ions with ~3 μm, ~5 μm, ~15 μm and ~15 μm spot sizes, respectively (fig. S3). From the 187 individual measurements, 60 were discarded due to having elevated ²⁰⁴Pb/²⁰⁶Pb ratios, which indicates terrestrial contamination (21). The remaining 127 measurements were used to construct a Pb-Pb isochron (line of constant age) (Fig. 3A). Fitting a linear model to the data indicates a mean age of 2830 ± 5 Ma [mean squared weighted deviation (MSWD) = 0.53, 95% confidence level].

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In seventeen of the low-Ti basaltic clasts, we identified clean grains of plagioclase - those that are free of mineral inclusions, mesostasis pockets, or mesostasis domains - making them suitable for analysis of RbSr isotopes (fig. S4). A total of thirty-two clean plagioclase grains and twenty-seven plagioclase grains with various amount of late-stage mesostasis (data S4) were measured using multiple-collector inductively coupled plasma mass spectrometry (21). The Rb-Sr measurements of grains with mesostasis domains and clean plagioclase follow a single isochron, with the clean plagioclase close to the initial ratio (Fig. 3B). The Rb-Sr isochron has a fitted model age of 2839 ± 95 Ma (MSWD = 2.3, 95% confidence level) and initial ⁸⁷Sr/⁸⁶Sr ratio of 0.69927 ± 0.00004 (2σ). This Rb-Sr age is consistent with (but less precise than) that derived from the Pb-Pb measurements.

The consistent ages and pyroxene composition (fig. S2B) indicate that the measured low-Ti basaltic clasts probably have a common origin. We adopt the higher precision Pb-Pb age of 2830 ± 5 Ma and interpret it as the crystallization age of the low-Ti basalt unit. This is older than the 2.0 Ga basalt sampled by CE-5 (7, 8), but demonstrates that volcanism occurred more recently than 3.0 Ga on both the near- and far-sides of the Moon.

Origin of the parent magma

We consider the intermediate-Ti and low-Ti basalt units identified by remote sensing as likely corresponding to the low-Ti and VLT basalts in our sample, respectively, on the basis of their pyroxene compositional trends (fig. S2). Those trends indicate that extensive evolution of the parent magmas increased the TiO₂ contents of the erupted lava to the low-Ti and intermediate-Ti categories (19). The Ti abundances we measured in the pyroxene grains are lower (data S1 and fig. S2A) than we expected from the remote sensing data (Fig. 1C). We regard this discrepancy as likely due to the very different sampling scales. The remote sensing TiO₂ measurement is an average value of a large area (20 m pixel⁻¹ in Fig. 1B), whereas the scooped soil sample collected by CE-6 was from an area of less than 1 m². Although we conclude that the low-Ti basaltic clasts are representative of the mare basalts local to the sampling site (21), we are unable to determine the provenance of the VLT clasts. They could be derived from the older mare unit to the east of the CE-6 landing site (Fig. 1A), or be fragments of underlying mare units that were excavated to the surface by impacts, or were transported to the sample site from more distant locations (19).

It has been suggested that lunar magmatism was sustained by radiogenic heating from KREEP components in the mantle sources of the magmas (24). However, studies of CE-5 basalt (25) and some ~3.0 Ga lunar meteorites (26) have found that these younger basalts do not contain a KREEP component. Because the CE-6 low-Ti basalt records similarly young basaltic volcanic activity on the farside, we investigate whether the mantle source contained a KREEP component by examining the initial Sr-Nd isotopic compositions and initial ²³⁸U/²⁰⁴Pb ratio (μ value).

We select the five analyses of troilites in the CE-6 basaltic clasts that have the highest measured ²⁰⁷Pb/²⁰⁶Pb ratios (data S2), 1.090 ± 0.007 (2σ), which we assume represents the initial ²⁰⁷Pb/²⁰⁶Pb composition. The initial ²⁰⁴Pb/²⁰⁶Pb ratio is more difficult to determine due to the low current abundance of ²⁰⁴Pb. We therefore constrain the initial ²⁰⁴Pb/²⁰⁶Pb ratio using the estimated initial ²⁰⁷Pb/²⁰⁶Pb and the best-fitting Pb-Pb isochron (Fig. 3A), which yields an initial ²⁰⁴Pb/²⁰⁶Pb of 0.00563 ± 0.00013 (2σ). We then use a two-stage lunar Pb isotopic evolution model (27) to estimate the μ value of the CE-6 low-Ti basalt mantle source. The model assumes the Moon formed at 4500 Ma and evolved as a single body, with initial Pb isotopes equal to the isotopic standard Canyon Diablo Troilite (28) and had a μ value of 460. Beginning at 4376 Ma in the model, the Moon differentiated to produce different mantle sources (27). Our application of this model indicates a μ value of 355 ± 8 for the CE-6 low-Ti basalt mantle source (Fig. 4A). This is much lower than the μ values of KREEP-rich basalts [> 2000 (27)] and the PKT basalt from CE-5 [~680 (7, 8)].

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The 32 clean plagioclase measurements yield an average initial ⁸⁷Sr/⁸⁶Sr ratio of 0.69922 ± 0.00013 (2σ), which is consistent with the initial ratio determined from the fitted Rb-Sr isochron (0.69927 ± 0.00004, 2σ), and lower than those of CE-5 basalts and most Apollo mare basalts (fig. S5A). We measured Sm-Nd isotopic compositions of domains containing late-stage mesostasis with high proportions of apatite in the CE-6 low-Ti basalt (fig. S4 and data S5). We find the ¹⁴⁷Sm/¹⁴⁴Nd ratios vary from 0.2049 to 0.2384, and ¹⁴³Nd/¹⁴⁴Nd from 0.51370 ± 0.00007 (2σ) to 0.51424 ± 0.00013 (2σ). The averaged initial ε_Nd (defined in equation S1) is 17.2 ± 2.4 (2σ, n = 8), which is higher than other lunar samples (fig. S5B).

We calculate the expected evolution of the depleted mantle and urKREEP (primordial KREEP from the lunar magma ocean) using an initial ⁸⁷Sr/⁸⁶Sr of 0.69903 and a chondrite-like initial ¹⁴³Nd/¹⁴⁴Nd. For the depleted mantle, ⁸⁷Rb/⁸⁶Sr and ¹⁴⁷Sm/¹⁴⁴Nd were set to 0.005 and 0.286, respectively. For urKREEP, they were set to 0.206 and 0.158, respectively, fitted to the plotted lunar samples in Fig. 4B, which shows the initial Sr-Nd isotopes of the CE-6 low-Ti basalt are compatible with our calculated Sr-Nd isotopic evolution trajectory for depleted lunar mantle with ⁸⁷Rb/⁸⁶Sr = 0.005 and ¹⁴⁷Sm/¹⁴⁴Nd = 0.286. The initial Sr-Nd -Pb isotopes of the CE-6 low-Ti basalt indicate a mantle source depleted in incompatible elements (elements that tend to remain in melts during partial melting or crystallization), containing no measurable KREEP component. The farside CE-6 low-Ti basalts, and nearside CE-5 basalts, indicate that heat-producing KREEP components were probably not responsible for the generation of their parent magmas.

It has been suggested that the asymmetry of lunar nearside and farside volcanic activity is due to differences in the thickness of the Moon’s crust (4, 29). The farside has a thicker crust [mean ~50 km compared to ~30 km on the nearside (30)], which could explain the lower level of volcanism. However, the SPA basin on the farside has a thinner crust (20-30 km (30)) than the mean, but still does not contain abundant mare basalts. The giant impact basins on the nearside, such as Imbrium, Serenitatis and Tranquillitatis, are all flooded by mare basalts, whereas the SPA basin, the largest lunar impact basin, contains few volcanic deposits (18).

The Sr-Nd-Pb isotopic signature of the CE-6 low-Ti basalt indicates it was sourced from a non-KREEP mantle source, whereas KREEP is widespread on the nearside. The very depleted mantle source could be related to the impact that formed the SPA basin, which had an excavation depth of 100 km (31). The SPA impact might have redistributed any sub-crustal KREEP material to the nearside of the Moon (11, 12), and induced partial melting of the mantle beneath the SPA basin, leaving a depleted mantle below SPA with low U/Pb and Rb/Sr ratios, and a high Sm/Nd ratio (fig. S6). Over time, Sr, Nd and Pb isotopic ratios evolved due to radioactive decay until they matched the isotopic compositions we measured for the CE-6 low-Ti basalts. Depleted mantle material would have a higher melting point temperature than mantle material that did contain a KREEP component (32). KREEP contains elements that generate heat through radioactivity (including K, Th and U), so the absence of KREEP in the CE-6 mantle source would correspond to a low heat flow in the SPA basin. We suggest a combination of these factors could explain the rarity of mare volcanism in the SPA basin.

Implications for lunar crater chronology

Isotopic dating provides absolute ages for locations on the Moon from which samples have been retrieved. The ages of other locations are indirectly estimated from the number and size of impact craters, calibrated to the locations with measured absolute ages. Models of this lunar crater chronology have shown that the impact rate on the Moon has varied over time (33). The lunar impact flux was high at early times, then rapidly declined to a nearly constant rate, but timing of that transition is poorly constrained. The canonical chronology model predicts that the transition occurred at ~3.0 Ga (33). However, the only absolute age available between ~3.0 to 0.8 Ga was the CE-5 basalts (7, 8). Our isotopic dating of the CE-6 mare basalt provides an additional calibration point at ~2.8 Ga.

Adding the CE-6 data point to a crater chronology model requires a determination of N(1), the spatial density of impact craters with diameter D ≥1 km, at the landing site. Prior to the launch of CE-6, predictions for the age of the landing site ranged from 2.42 to 3.33 Ga (5, 14, 19, 34) due to differences in the determinations of N(1). We adopt N(1) = (2.01 ± 0.90) × 10⁻³ km⁻² from a study (35) of craters with diameters ~200 m to 2 km in multiple areas of the mare beneath the CE-6 landing site. We discuss this choice of N(1) in Supplementary Text.

Using the measured date and N(1) value for the CE-6 landing site, we re-calibrate the lunar crater chronology model using least square fitting (Fig. 5A). We find

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N= 1.94 × 10⁻¹⁴(e^7.196t – 1) + 7.652 × 10⁻⁴t (1)

(1)

where t is time in Ga. This chronology model implies a constant impact flux after 2.83 Ga, slightly earlier than the canonical model (Fig. 5B).

{ https://www.science.org/journal/science }

19-11-2024 om 17:03 geschreven door peter  

Story by Samir Sebti

 

Astronomers at the Complutense University of Madrid first spotted this intriguing event using a powerful telescope in Sutherland, South Africa. The tiny asteroid, measuring just 37 feet wide, has been temporarily ensnared by Earth’s gravitational pull, transforming it into a mini-moon.

Richard Binzel, an astronomer at the Massachusetts Institute of Technology (MIT), explains, “These happen with some frequency, but we rarely see them because they’re very small and very hard to detect. Only recently has our survey capability reached the point of spotting them routinely.”

While Earth’s primary moon boasts a diameter of 2,159 miles, 2024 PT5 is comparatively minuscule. To put it in perspective :

• Earth’s moon : 2,159 miles wide
• Asteroid 2024 PT5 : 37 feet wide$
• Size difference : Earth’s moon is over 300,000 times wider

Despite its small size, this temporary satellite provides valuable insights into our cosmic neighborhood and the dynamics of near-Earth objects.

The journey of Earth’s new mini-moon

Asteroid 2024 PT5 belongs to the Arjuna asteroid belt, a group of space rocks that follow orbits similar to Earth’s, approximately 93 million miles from the sun. Some Arjuna asteroids can approach our planet at a close range of around 2.8 million miles, traveling at relatively low velocities of less than 2,200 miles per hour.

According to data from NASA’s Jet Propulsion Laboratory Horizons system, 2024 PT5’s stay in Earth’s orbit will be brief. The capture began at 3 :54 p.m. EDT on September 29, 2024, and is expected to end at 11 :43 a.m. EDT on November 25, 2024.

Carlos de la Fuente Marcos, a professor and mini-moon expert from the Complutense University, likens the asteroid’s behavior to that of a window shopper. He states, “Asteroid 2024 PT5 will not describe a full orbit around Earth. You may say that if a true satellite is like a customer buying goods inside a store, objects like 2024 PT5 are window shoppers.”

This celestial visitor’s journey serves as a reminder of the dynamic nature of our solar system. While it won’t remain in Earth’s orbit for billions of years like our primary moon, its fleeting presence offers a unique opportunity for scientific study.

The significance of mini-moons in astronomical research

Mini-moons like 2024 PT5 provide scientists with valuable opportunities to study near-Earth objects up close. These temporary captures act as natural cosmic laboratories, offering insights into the composition of asteroids and the intricate workings of our solar system.

Binzel emphasizes the importance of these events, stating, “These temporary captures are natural cosmic laboratories. They help us understand the small bodies that come close to Earth and could be important for future space missions.”

While mini-moons are too small and dim for most amateur astronomers to observe, they fall within the detection range of professional-grade telescopes. To spot 2024 PT5, one would need :

The study of mini-moons contributes to our understanding of near-Earth asteroids and their potential impact on our planet. By analyzing these temporary satellites, scientists can refine their models of asteroid behavior and improve our ability to predict and mitigate potential collisions.

Future implications and ongoing research

As technology advances, researchers hope to study these fleeting visitors more closely. Future missions may even attempt to gather samples or test new spacecraft designs using mini-moons as targets.

The discovery of 2024 PT5 and other mini-moons highlights the ever-changing nature of our cosmic environment. It serves as a reminder that our solar system is a dynamic place, full of surprises and opportunities for scientific exploration.

While Earth’s second moon may be temporary, its presence opens up new avenues for research and discovery. As we continue to scan the skies, who knows what other celestial wonders we might uncover ? The universe never ceases to amaze, and each new finding brings us one step closer to unraveling its mysteries.

{ https://dailygalaxy.com/category/astronomy/ }

18-11-2024 om 23:30 geschreven door peter  

The problems arise from the combination of Mars’ ultra-thin atmosphere—which is over 100 times thinner than Earth’s — and the ultra-large size of spacecraft needed for human missions, likely between 20 – 100 metric tons.

“Many people immediately conclude that landing humans on Mars should be easy,” Manning said back in 2007, “since we’ve landed successfully on the Moon and we routinely land human-carrying vehicles from space to Earth. And since Mars falls between the Earth and the Moon in size and in the amount of atmosphere, then the middle ground of Mars should be easy.”

But Mars’ atmosphere provides challenges not found on Earth or the Moon. A large, heavy spacecraft  streaking through Mars’ thin, volatile atmosphere only has just a few minutes to slow from incoming interplanetary speeds (for example, the Perseverance rover was traveling 12,100 mph [19,500 kph] when it reached Mars) to under Mach 1, and then quickly transition to a lander to slow to be able to touch down gently.

In 2007, the prevailing notion among EDL engineers was that there’s too little atmosphere to land like we do on Earth, but there is actually too much atmosphere on Mars to land heavy vehicles like we do on the Moon by using propulsive technology alone.

“We call it the Supersonic Transition Problem,” said Manning, again in 2007. “Unique to Mars, there is a velocity-altitude gap below Mach 5. The gap is between the delivery capability of large entry systems at Mars and the capability of super-and sub-sonic decelerator technologies to get below the speed of sound.”

The largest payload to land on Mars so far is the Perseverance rover, which has a mass of about 1 metric ton. Successfully landing Perseverance and its predecessor Curiosity required a complicated, Rube Goldberg-like series of maneuvers and devices such as the Sky Crane. Larger, human-rated vehicles will be coming in even faster and heavier, making them incredibly difficult to slow down.

“So, how do you slow down to subsonic speeds,” Manning said now in 2024 as the chief engineer at JPL, “to get to speeds where traditionally we know how to fire our engines to enable touchdown? We thought bigger parachutes or supersonic decelerators like LOFTID (Low-Earth Orbit Flight Test of an Inflatable Decelerator) tested by NASA) would allow us to maybe slow down better, but there were still issues with both those devices.”

“But there was one trick we didn’t know anything about it,” Manning continued. “How about using your propulsion system and firing the engines backwards —retro propulsion — while you are flying at supersonic speeds to shed velocity? Back in 2007, we didn’t know the answer to that. We didn’t even think it was possible.”

Why not? What could go wrong?

“When you fire engines backwards as you are moving through an atmosphere, there’s a shock front that forms and it would be moving around,” Manning explained, “so it could come along and whack the vehicle and cause it to go unstable or cause damage. You’re also flying right into the plume of the rocket engine exhaust, so there could be extra friction and heating possibilities on the vehicle.”

All of this is very hard to model and there was virtually no experience doing it, as in 2007, no one had ever used propulsive technology alone to slow and then land a spacecraft back on Earth. This is mostly because our planet’s beautiful, luxuriously thick atmosphere slows a spacecraft down easily, especially with a parachute or creative flying as the space shuttle did.

“People did study it a bit, and we came to the conclusion it would be great to try it and find out whether we could fire engines backwards and see what happens,” Manning mused, adding that there wasn’t any extra funding laying around to launch a rocket just to watch it come down again to see what happened.

But then, SpaceX started doing tests in attempt to land their Falcon 9’s first stage booster back on Earth to re-use them.

“SpaceX said they were going to try it,” Manning said, “And to do that they needed to slow the booster down in the supersonic phase while in Earth’s upper atmosphere. So, there’s a portion of the flight where they fire their engines backwards at supersonic speeds through a rarified atmosphere which is very much what’s like at Mars.”

As you can imagine, this was incredibly intriguing to EDL engineers thinking about future Mars missions.

After a few years of trial, error, and failures, on September 29, 2013, SpaceX performed the first supersonic retropropulsion (SRP) maneuver to decelerate the reentry of the first stage of their Falcon 9 rocket. While it ultimately hit the ocean and was destroyed, the SRP actually worked to slow down the booster.

NASA asked if their EDL engineers could watch and study SpaceX’s data, and SpaceX readily agreed. Beginning in 2014, NASA and SpaceX formed a three-year public-private partnership centered on SRP data analysis called the NASA Propulsive Descent Technology (PDT) project.  The F9 boosters were outfitted with special instruments to collect data specifically on portions of the entry burn which fell within the range of Mach numbers and dynamic pressures expected at Mars. Additionally, there were visual and infrared imagery campaigns, flight reconstruction, and fluid dynamics analysis – all of which helped both NASA and SpaceX.

To everyone’s surprise and delight, it worked. On December 21, 2015, an F9 first stage returned and successfully landed on Landing Zone 1 at Cape Canaveral, the first-ever orbital class rocket landing. This was a game changing demonstration of SRP, which advanced the knowledge and tested the technology of using SRP on Mars.

“Based on the analyses completed, the remaining SRP challenge is characterized as one of prudent flight systems engineering dependent on maturation of specific Mars flight systems, not technology advancement,” wrote an EDL team, detailing the results of the PDT project in a paper. In short, SpaceX’s success meant it wouldn’t require any fancy new technology or breaking the laws of physics to land large payloads on Mars.

“It turns out, we learned some new physics,” Manning said. They found that the shock front ‘bubble’ created around the vehicle by firing the engines somehow insulates the spacecraft from any buffeting, as well as from some of the heating.

EDL engineers now believe that SRP is the only Mars entry, descent and landing technology that is intrinsically scalable across a wide range and size of missions to shed enough velocity during atmospheric flight to enable safe landings. Alongside aerobraking, this is one of the leading means of landing heavy equipment, habitats and even humans on Mars.

But still, numerous issues remain unsolved when it comes to landing a human mission on Mars. Manning mentioned there are multiple unknowns, including how a big ship such as SpaceX’s Starship would be steered and flown through Mars’ atmosphere; can fins be used hypersonically or will the plasma thermal environment melt them? The amount of debris kicked up by large engines on human-sized ship could be fatal, especially for the engines you’d like to reuse for returning to orbit or to Earth, so how do you protect the engines and the ship? Mars can be quite windy, so what happens if you encounter wind shears or a dust storm during landing? What kind of landing legs will work for a large ship on Mars’ rocky surface? Then there are logistics problems such as how will all the infrastructure get established? How will ships be refueled to return home?

“This is all going to take a lot of time, more time than people realize,” Manning said. “One of the downsides of going to Mars is that it is hard to do trial and error unless you are very patient. The next time you can try again is 26 months later because of the timing of the launch windows between our two planets. Holy buckets, what a pain that is going to be! But I think we’re going to learn a lot whenever we can try it for the first time.”

And at least the supersonic retropropulsion question has been answered.

“We’re basically doing what Buck Rogers told us to do back in the 1930s: fire your engines backwards while you’re going really fast.”

2007 article: 

• The Mars Landing Approach: Getting Large Payloads to the Surface of the Red Planet

{ https://www.universetoday.com/ }

18-11-2024 om 23:08 geschreven door peter  

Rock and thin section images of the Bruce’s Hill and Umbaumba sections.

The Earth has always been bombarded with rocks from space. It’s true to say though that there were more rocks flying around the Solar System during earlier periods of its history. A team of researchers have been studying a meteorite impact from 3.26 billion years ago. They have calculated this rock was 200 times bigger than the one that wiped out the dinosaurs. The event would have triggered tsunamis mixing up the oceans and flushing debris from the land. The newly available organic material allowed organisms to thrive. 

Meteorite impacts are a common event and its not unusual to see these rocks from space whizzing through the atmosphere. Giant meteorite impacts have become an important part of Earth’s geological history. The impacts release colossal amounts of energy that can destroy life, create wildfires, tsunamis and eject dust into the atmosphere. The Chicxulub impact around 66 million years ago is perhaps one of the most well known impacts and wiped out the dinosaurs. The study of these interplanetary wanderers is imperative as we strive to protect ourselves from potential impactors that pose a threat to human life. 

A bright meteor caught by one of the Global Fireball Network’s cameras from the Rancho Mirage Observatory (Eric McLaughlin) on April 7, 2019.

Credit: NASA Meteorite Tracking and Recovery Network.

Impacts like these have had a massive affect on the development of Earth and its suitability for life. Geological studies of rocks from the Archean Eon have revealed 16 major impacts with impactors measuring at least 10km in diameter. At the time of impact the effects can be devastating but over time, their can be benefits to life although it’s not well understood. In a paper published in Earth, Atmospheric and Planetary Sciences the team led by Nadja Drabon from Harvard University explore rocks from an event 3.26 billion years ago. 

Known as the S2 event, the impactor is believed to be a carbonaceous chondrite between 37 to 58 km in diameter. It is thought to have exploded over South Africa with debris landing in the ocean causing giant tsunamis. The impact mixed up iron(II) rich deep waters with the iron(II) poor shallower waters. It will have also caused the waters to heat leading to partial evaporation of surface water with a temporary increase in erosion around coastal areas. 

Perhaps one of the most valuable effects of the impact was the injection of phosphorus into the atmosphere with a positive impact on the Earth’s habitability for life. Study of the layers of rock above the layer caused by the S2 event reveals an increased amount of nutrients and iron which helped microbial life to thrive. 

The study has helped to build a clearer understanding of how giant impacts can aid the development of life. It does of course depend on the size and type, material and the conditions of the atmosphere before the event. The S2 event seems to have quite a mixed effect on early life, in particular marine life. Overall some forms of life were positively impacted while others seemed to have experienced challenges. Marine life that relies upon sunlight to survive (the phototrophs) were effected by the darkness while those living at lower depths were less influenced. The detrimental effects of the atmosphere would likely only have been short lived lasting perhaps just a few years before recovering quickly causing only a temporary impact to marine life. But the injection of phosphorous in the atmosphere would have had far more long term beneficial effects to life. 

Source : 

• Effect of a giant meteorite impact on Paleoarchean surface environments and life

{ https://www.universetoday.com/ }

17-11-2024 om 18:51 geschreven door peter  

Story by Samir Sebti

Mysterious hourly radio signal from space baffles scientists, challenging current astrophysical theories

© Daily Galaxy

The ASKAP radio telescope in Australia first detected this extraordinary signal, officially designated as ASKAP J1935+2148. What sets this signal apart is its clockwork-like precision, repeating every 53.8 minutes. However, the true mystery lies in its three distinct emission states :

• Bright flashes lasting 10 to 50 seconds with linear polarization
• Weak pulses with circular polarization, lasting a mere 370 milliseconds
• Periods of complete silence

Dr. Manisha Caleb, the lead author of the study, emphasizes the uniqueness of this discovery : “What is intriguing is how this object displays three distinct emission states, each with properties entirely dissimilar from the others.” The MeerKAT radio telescope in South Africa played a crucial role in confirming that these varied signals originated from the same celestial source.

For astronomy enthusiasts fascinated by such cosmic mysteries, it’s worth noting that you can build your own home radio telescope to capture signals from across the universe, potentially contributing to future discoveries.

NASA's Plan to Build A Telescope on the Moon

Challenging conventional astrophysical wisdom

As scientists grapple with explaining this phenomenon, they’ve narrowed down the potential sources to two prime suspects : neutron stars and white dwarfs. Both are remnants of deceased stars, but their properties differ significantly. Here’s a comparison of these celestial objects :

While neutron stars are known for emitting radio waves, their typical rotation speeds are much faster than the observed 54-minute cycle. On the other hand, white dwarfs could potentially rotate this slowly, but scientists are unaware of any mechanism that would allow them to produce such complex radio signals.

Exploring potential explanations and implications

The scientific community is abuzz with theories attempting to explain this celestial oddity. Some researchers speculate that the signal could be produced by interactions between a neutron star’s strong magnetic field and complex plasma flows. However, this explanation falls short when considering the unusually slow rotation rate.

Another intriguing possibility is the existence of an elusive “white dwarf pulsar,” a hypothetical object that combines properties of both white dwarfs and pulsars. This concept, while theoretically possible, has yet to be confirmed observationally.

The implications of this discovery extend far beyond this single celestial object. Dr. Caleb suggests that it might prompt a reconsideration of our long-held understanding of neutron stars and white dwarfs, including :

• The mechanisms behind their radio wave emissions
• The diversity of their populations within the Milky Way galaxy
• Potential new subclasses of these stellar remnants

This isn’t the first time a repeating radio signal has baffled scientists. A previous discovery of an 18-minute looping signal also defied explanation, but this new 54-minute cycle adds another layer of complexity to the cosmic puzzle.

Future research and the quest for answers

As astronomers continue to probe the depths of space, the hunt for answers intensifies. The ASKAP and MeerKAT radio telescopes will undoubtedly play crucial roles in future observations of this mysterious object. Additionally, other advanced instruments like the Square Kilometre Array (SKA) and the Very Large Array (VLA) may be enlisted to gather more data and potentially unravel this cosmic enigma.

While the possibility of extraterrestrial intelligence is always a tantalizing thought, scientists emphasize that natural astrophysical phenomena are far more likely explanations. Nevertheless, this discovery underscores the vast unknowns that still exist in our universe and the exciting potential for groundbreaking discoveries that challenge our understanding of cosmic physics.

As we continue to push the boundaries of astronomical research, one thing remains clear : the universe never fails to surprise us with its complexity and wonder. This hourly repeating radio signal serves as a reminder of the countless mysteries that await discovery in the depths of space, inspiring future generations of scientists to explore the cosmos and unravel its secrets.

Source : 

• https://www.sydney.edu.au/news-opinion/news/2024/06/05/slow-spinning-radio-neutron-star-breaks-all-the-rules.html

{ https://dailygalaxy.com/ }

16-11-2024 om 21:09 geschreven door peter  

NASA tracking bus-sized asteroid making close approach to Earth TOMORROW

• READ MORE:  NASA staff beg Musk to 'clean house' after agency overspending

By ELLYN LAPOINTE FOR DAILYMAIL.COM

NASA is keeping a close eye on a bus-sized asteroid that is expected to skim past Earth Saturday at a distance only slightly father away than the moon.

Officials at the space agency's Jet Propulsion Laboratory (JPL) and and Center for Near-Earth Object Studies (CNEOS) estimated that the space rock is between 28 and 62 feet wide, and will shoot past our planet at a speed of roughly 29,300 mph.

It will come within 273,000 miles of Earth. By comparison, the average distance between our planet and the moon is roughly 238,900 miles.

The close encounter is expected to take place in the early morning hours, but the asteroid poses no threat to Earth.

The space rock, called 2024 VK3, is just one of five asteroids that will fly by our planet this weekend. 

Three are as roughly big as commercial airplanes and one is about the size of a house, according to NASA JPL. 

The next-closest encounter will be made by the airplane-sized asteroid 2024 VZ2, which will come within 790,000 miles of our planet. 

The others will maintain distances of over a million miles away with house-sized asteroid 2024 UC5 being 2,580,000 miles away at its closest point to Earth. 

NASA is keeping a close eye on a bus-sized asteroid that is expected to skim past Earth tomorrow morning at a distance only slightly father away than the moon

All of these asteroids are considered Near Earth Objects (NEOs) because they are within approximately 30 million miles of our planet. 

NASA has observed, documented and classified around 36,000 objects in the solar system as NEOs.

The space agency tracks NEOs primarily to identify asteroids that could potentially collide with Earth, and assess the threat they pose.

NASA uses a variety of methods to survey nearby space rocks, including both ground-based and space-based telescopes.

One key tool is the Near-Earth Object Surveyor, an infrared space telescope used to discover and characterize Potentially Hazardous Asteroids (PHAs).

PHAs are asteroids that have a high probability of making a close approach to Earth and are large enough to cause significant damage if they made impact. 

Technically, that means any space rock that comes within 0.05 astronomical units - or roughly 4,647,790 miles - of Earth's orbit, and has an absolute brightness of 22.0 or less. 

Absolute brightness is an indirect measurement of an asteroid's size. Lower values of magnitude indicate greater brightness, and thus larger objects. 

In 2021, NASA's Planetary Defense Office launched the DART mission, which slammed a spacecraft into the asteroid Dimorphos and changed the space rock's trajectory (STOCK) 

None of the asteroids that will fly by Earth this weekend are considered PHAs.

But NASA is preparing for the unlikely event that a PHA hurtles towards our planet in the future.

The agency's Planetary Defense Coordination Office (PDCO) is developing technologies and strategies that could safe Earth from a catastrophic asteroid impact. 

Established in 2016, PDCO is tasked with the mission of finding, tracking and better understanding asteroids and comets that could pose an impact hazard to Earth. 

In 2021, the office launched the Double Asteroid Redirection Test (DART), which slammed a spacecraft into the asteroid Dimorphos and successfully changed the space rock's orbital trajectory. 

This mission was a test of the 'kinetic impact' asteroid deflection strategy, which could one day be used to redirect a PHA on a collision course with Earth. 

In October, the European Space Agency launched the second phase of this mission, called Hera.

The Hera spacecraft is currently on its way to Dimorphos to perform a detailed post-impact survey of Dimorphos. This will help experts solidify kinetic impact into a well-understood and repeatable planetary defense technique.

{ https://www.dailymail.co.uk/ }

16-11-2024 om 18:46 geschreven door peter  

Minerals in Lafayette Meteorite Were Exposed to Martian Liquid Water 742 Million Years Ago: Study

An asteroid struck Mars 11 million years ago and sent pieces of the planet hurtling through space; one of these chunks eventually crashed into the Earth. During early investigations of this object, named Lafayette meteorite, scientists discovered that it had interacted with liquid water while on Mars. Now, researchers from the United States and the United Kingdom have determined the age of the minerals in the meteorite that formed when there was liquid water.

The Lafayette meteorite was chipped off the surface of Mars and then sped through space for roughly 11 million years. It eventually found its way into a drawer at Purdue University in 1931 and has since been teaching scientists about Mars.

Image credit: Purdue Brand Studio.

Meteorites are solid time capsules from planets and celestial bodies from our Universe.

They carry with them bits of data that can be unlocked by geochronologists.

They set themselves apart from rocks that may be found on Earth by a crust that forms from its descent through our atmosphere and often form a fiery entrance visible in the night’s sky.

“We can identify meteorites by studying what minerals are present in them and the relationships between these minerals inside the meteorite,” said Dr. Marissa Tremblay, a researcher at Purdue University.

“Meteorites are often denser than Earth rocks, contain metal, and are magnetic.”

“We can also look for things like a fusion crust that forms during entry into Earth’s atmosphere.”

“Finally, we can use the chemistry of meteorites (specifically their oxygen isotope composition) to fingerprint which planetary body they came from or which type of meteorite it belongs to.”

According to the authors, some Martian meteorites, such as a 0.8-kg nakhlite meteorite called the Lafayette meteorite, contain minerals that formed through interaction with liquid water while still on Mars.

“Dating these minerals can therefore tell us when there was liquid water at or near the surface of Mars in the planet’s geologic past,” Dr. Tremblay said.

“We dated these minerals in the Martian meteorite Lafayette and found that they formed 742 million years ago.”

“We do not think there was abundant liquid water on the surface of Mars at this time.”

“Instead, we think the water came from the melting of nearby subsurface ice called permafrost, and that the permafrost melting was caused by magmatic activity that still occurs periodically on Mars to the present day.”

The researchers demonstrated that the age obtained for the timing of water-rock interaction on Mars was robust and that the chronometer used was not affected by things that happened to the Lafayette meteorite after it was altered in the presence of water.

“The age could have been affected by the impact that ejected the Lafayette meteorite from Mars, the heating Lafayette experienced during the 11 million years it was floating out in space, or the heating Lafayette experienced when it fell to Earth and burned up a little bit in Earth’s atmosphere,” Dr. Tremblay said.

“But we were able to demonstrate that none of these things affected the age of aqueous alteration in Lafayette.”

“This meteorite uniquely has evidence that it has reacted with water,” said Dr. Ryan Ickert, also from Purdue University.

“The exact date of this was controversial, and our publication dates when water was present.”

“We know this because once it was ejected from Mars, the meteorite experienced bombardment by cosmic ray particles in outer space, that caused certain isotopes to be produced in Lafayette,” Dr. Tremblay said.

“Many meteoroids are produced by impacts on Mars and other planetary bodies, but only a handful will eventually fall to Earth.”

• The findings were published this month in the journal Geochemical Perspective Letters.
• M.M. Tremblay et al. 2024. Dating recent aqueous activity on Mars. Geochemical Perspectives Letters 32; doi: 10.7185/geochemlet.2443

{ https://www.sci.news/ }

16-11-2024 om 16:18 geschreven door peter  

The variable star is a type of red giant called a Mira-type variable. It’s a complete opposite to its companion star. Rather than extremely compact and dense, the red giant is bloated and red. It’s more than 400 times larger than the Sun. It’s a pulsating giant star that’s more at home atop Sauron’s Dark Tower than it is in a catalogue of stars. As it pulses, it changes temperature and luminosity. Over an approximately 390-day period, its brightness changes by a factor of 750.

That means that when the star is at its peak brightness, it’s more than 5,000 times as bright as our Sun.

The powerful pulsing of this massive red star is enough to be a spectacle in itself. But it’s relationship with its binary partner creates an even more spectacular display. As the two orbit, the dense white dwarf draws hydrogen gas away from the red giant. The hydrogen accumulates on the white dwarf until the star can’t take it anymore. Then the hydrogen explodes in nuclear fusion on the surface of the small, dense star.

The nova explosion ejects the material into space in gaseous filaments. But the region around white dwarfs is dominated by the star’s powerful magnetic fields, which can be millions of times stronger than Earth’s. The force of the nuclear explosion and the magnetic fields twist the gaseous hydrogen filaments into trails and streamers, and eventually, they loop back on themselves and form spiral patterns.

We can only see this nebula of gaseous filaments because the radiation from both stars strips electrons from the hydrogen, turning it into ionized gas. The ionized hydrogen glows brightly and creates a beautiful natural display.

The central binary star’s brightness changes over time because of the pulsing of the red giant. The gas appears red to us, but not because of the red giant. R Aquarii is in a dusty region, and the dust absorbs all the blue light, with only red reaching us.

A Hubble timelapse consisting of five images of R Aquarii from 2014 to 2023 helps bring the dynamic interplay to life.

Looking at these images, it’s easy to misunderstand the scale of the stars, the nebula, and the brightly-lit, filaments of ionized hydrogen. However, the material blasted into space reaches as far as 400 billion kilometers (248 billion miles). For comparison, that’s about 24 times greater than our Solar System’s diameter.

R Aquarii was first observed by German astronomer Karl Ludwig Harding in 1810, when he was a colleague of Carl Friedrich Gauss at Gottingen Observatory. It’s one of the nearest symbiotic stars, and is an object that astronomers are very interested in observing. In the 20th century, Edwin Hubble and others studied it and recognized its complex interactions and the resulting nebula. R Aquarii and its brethren can teach astronomers a lot about stellar winds, accretion, and ionized nebula.

{ https://www.universetoday.com/ }

16-11-2024 om 15:49 geschreven door peter  

To develop their 3D modeling tool, the team looked at polarized radio light, which vibrates in a specific direction. The research team then factored in the effect called “Faraday rotation,” where the the polarization of light rotates along the direction of propagation in proportion to the projection of a magnetic field. Named after Michael Faraday, this effect was the first experimental evidence that light and electromagnetism are related. In the case of radio waves, the rotation depends on how much material they have passed through. 

With this technique, the team examined various radio image samples obtained by the Australian Square Kilometer Array Pathfinder Telescope (ASKAP) and MeerKAT radio telescopes. They found they could estimate how far each part of the radio light had traveled, enabling them to create a 3D model of phenomena happening millions of light-years away. This technique also allowed the team to demonstrate, for the first time, how the line-of-sight orientation of relativistic jets can be determined.

They also examined the supermassive black hole (SMBH) at the heart of the M87 galaxy. Using their technique, the team was able to show how material ejected interacts with cosmic winds and space weather and also analyzed the structures of the jet’s magnetic fields in space. As Rudnick said in a recent University of Minnesota press release:

“We found that the shapes of the objects were very different from the impression that we got by just looking at them in a 2D space. Our technique has dramatically altered our understanding of these exotic objects. We may need to reconsider previous models on the physics of how these things work. There is no question in my mind that we will end up with lots of surprises in the future that some objects will not look like we thought in 2D.”

The team recommends using this technique to reevaluate all previous analyses of polarized light sources. They also hope this technique will be applied to images taken by next-generation telescopes around the world. This includes the new Square Kilometer Array (SKA-Phase2) project, which will extend the facility to about 2000 dishes, making it 50 times more sensitive and 10,000 times faster than any other radio telescope in the world.

Further Reading: 

• UofM-CSE, 
• MNRAS

{ https://www.universetoday.com/ }

16-11-2024 om 15:36 geschreven door peter  

But while this scenario is relatively straightforward, the devil is in the details. In order for this process to work there must be liquid water underground. And some other mechanism needs to be able to remove the methane, or at least make this process cycle on and off every few months.

That opens up the possibility for life. We know of forms of life on Earth known as methanogens that do not get their energy from photosynthesis. Instead they essentially eat hydrogen and produce methane as a byproduct. The advantage of using life to explain the Martian methane mystery is that it can potentially naturally introduce seasonal variations. When conditions change under the Martian surface, for example through the warming summer months or cooling winter months, then the life can respond appropriately.

But while this hypothesis explains the seasonal variation, it doesn’t get around the fact that the Martian life would still need a source of water to live. Plus, we have absolutely no evidence for any life appearing on Mars, even in its distant past.

To date there is no clear consensus as to what is causing the seasonal variations of methane on Mars. The idea of life under the surface of the red planet remains a tantalizing possibility. The only way to answer this is to keep sending missions back to Mars and start digging.

{ https://www.universetoday.com/ }

16-11-2024 om 15:22 geschreven door peter  

Landing 12 people on the moon remains one of NASA's greatest achievements, if not the greatest.

Astronauts on the Apollo missions of the 1960s and '70s collected rocks, took photos, performed experiments, planted flags, and then came home. But those stays didn't establish a lasting human presence on the moon.

More than 50 years after the most recent crewed moon landing — Apollo 17 in December 1972 — there are plenty of reasons to return people to Earth's giant, dusty satellite and stay there.

We're getting closer. In February, a US lunar lander touched down on the moon's surface for the first time since Apollo 17. The uncrewed Nova-C lander, named Odysseus, was designed by the Houston company Intuitive Machines with a $118 million contract from NASA. It was the first commercial mission to touch down on the moon and a huge step toward new human landings.

NASA has promised we will see US astronauts on the moon again soon-ish — maybe by September 2026 at the earliest, in a program called Artemis, which is set to include the first woman, first Black astronaut, and first Canadian to touch the lunar surface.

Jim Bridenstine, who ran NASA during the Trump administration, said it's not science or technology hurdles that have held the US back from doing this sooner.

"If it wasn't for the political risk, we would be on the moon right now," Bridenstine said on a phone call with reporters in 2018. "In fact, we would probably be on Mars."

Why a permanent crewed lunar base is worth it

Researchers and entrepreneurs have long pushed for the creation of a crewed base on the moon — a lunar space station.

"A permanent human research station on the moon is the next logical step. It's only three days away. We can afford to get it wrong and not kill everybody," Chris Hadfield, a former astronaut, previously told Business Insider. "And we have a whole bunch of stuff we have to invent and then test in order to learn before we can go deeper out."

A lunar base could evolve into a fuel depot for deep-space missions, lead to the creation of unprecedented space telescopes, make it easier to live on Mars, and solve long-standing scientific mysteries about Earth and the moon's creation. It could even spur a thriving off-world economy, perhaps one built around lunar space tourism.

But many astronauts and other experts suggest the biggest impediments to making new crewed moon missions a reality are banal and somewhat depressing.

It's really expensive to get to the moon — but not that expensive

A tried-and-true hurdle for any spaceflight program, especially missions that involve people, is the steep cost.

NASA's 2024 budget was $24.9 billion, which may sound like a windfall until you consider that the total gets split among all the agency's divisions and ambitious projects: the James Webb Space Telescope, the giant rocket project called Space Launch System, and far-flung missions to the sun, Jupiter, Mars, the asteroid belt, the Kuiper belt, and the edge of our solar system. 

By contrast, the US defense budget for 2024 is about $883.7 billion.

With such a tight budget, NASA is vulnerable to government gridlocks. Congress was slow to pass its 2024 budget — a delay NASA cited as a major reason for laying off 8% of its workforce at the Jet Propulsion Laboratory in February.

Plus, NASA's budget is somewhat small relative to its past.

"NASA's portion of the federal budget peaked at 4% in 1965," Walter Cunningham, an Apollo 7 astronaut, said during congressional testimony in 2015.

In comparison, NASA's 2024 budget represents roughly 0.36% of US spending, according to a report from the Planetary Society. It has fluctuated between 0.4% and 1% since the 1970s, the report said.

Returning to the moon costs a significant chunk of that budget. A 2021 report from NASA estimated that the Artemis program to return people to the moon would cost a total of $93 billion from 2012 through 2025.

The Apollo program, by comparison, cost about $257 billion in today's dollars.

"Manned exploration is the most expensive space venture and, consequently, the most difficult for which to obtain political support," Cunningham said during his 2015 testimony.

He added, according to Scientific American: "Unless the country, which is Congress here, decided to put more money in it, this is just talk that we're doing here."

Referring to Mars missions and a return to the moon, Cunningham said, "NASA's budget is way too low to do all the things that we've talked about."

The problem with presidents

President Joe Biden will no longer be in office in 2026, when NASA plans to send astronauts back to the moon.

And therein lies another major problem: partisan political whiplash.

"Why would you believe what any president said about a prediction of something that was going to happen two administrations in the future?" Hadfield previously told BI. "That's just talk."

The process of designing, engineering, and testing a spacecraft that could get people to another world easily outlasts a two-term president. But incoming presidents and lawmakers often scrap the previous leader's space-exploration priorities.

"I would like the next president to support a budget that allows us to accomplish the mission that we are asked to perform, whatever that mission may be," Scott Kelly, a retired astronaut who spent a year in space, wrote in a Reddit "Ask Me Anything" thread in January 2016, before Donald Trump took office.

But presidents and Congress don't often seem to care about staying the course.

In 2004, for example, the Bush administration tasked NASA to come up with a way to replace the space shuttle, which was set to retire, and also return to the moon. The agency came up with the Constellation program to land astronauts on the moon using a rocket called Ares and a spaceship called Orion.

NASA spent $9 billion over five years designing, building, and testing hardware for that human-spaceflight program.

Yet after President Barack Obama took office — and the Government Accountability Office released a report about NASA's inability to estimate a realistic cost for Constellation — Obama pushed to scrap the program and signed off on the SLS rocket instead.

Trump didn't scrap SLS, but he did change Obama's goal of launching astronauts to an asteroid, shifting priorities to moon and Mars missions. Trump wanted to see Artemis land astronauts back on the moon in 2024.

Such frequent changes to NASA's expensive priorities have led to cancellation after cancellation, a loss of about $20 billion, and years of wasted time and momentum.

Biden seems to be a rare exception to the shifty presidential trend: He hasn't toyed with Trump's Artemis priority for NASA, and he's also kept the Space Force intact.

For Trump's second term, some space industry experts told BI that SpaceX founder Elon Musk could influence the space agenda and help finally get the US back to the moon and, ultimately, to Mars.

Buzz Aldrin said in testimony to Congress in 2015 that he believed the will to return to the moon must come from Capitol Hill.

"American leadership is inspiring the world by consistently doing what no other nation is capable of doing. We demonstrated that for a brief time 45 years ago. I do not believe we have done it since," Aldrin wrote in a statement. "I believe it begins with a bipartisan congressional and administration commitment to sustained leadership."

The real driving force behind that government commitment to return to the moon is the will of the American people, who vote for politicians and help shape their policy priorities. But public interest in lunar exploration has always been lukewarm.

Even at the height of the Apollo program, after Aldrin and Neil Armstrong stepped onto the lunar surface, only 53% of Americans said they thought the program was worth the cost. For the most part, US approval of Apollo hovered below 50%.

A 2023 Pew Research Poll found most Americans said NASA should continue leading space exploration. But that doesn't mean people care about going back to the moon — only 12% of the 10,329 respondents said NASA should prioritize human lunar missions.

Support for crewed Mars exploration isn't much stronger, with 11% of the poll's respondents saying it should be a NASA priority. Meanwhile, 60% said scanning the skies for killer asteroids was important.

The challenges beyond politics include problematic regolith and eye-popping temperature fluctuations

The political tug-of-war over NASA's mission and budget isn't the only reason people haven't returned to the moon. The moon is also a 4.5-billion-year-old death trap for humans and must not be trifled with or underestimated.

Its surface is littered with craters and boulders that threaten safe landings. The US government spent what would be tens of billions in today's dollars to develop, launch, and deliver satellites to the moon to map its surface and help mission planners scout for Apollo landing sites.

But a bigger worry is what eons of meteorite impacts have created: regolith, also called moon dust.

Following the Apollo missions, scientists quarantined the astronauts for two weeks after they landed, in part because they were worried about the effects of the dust, according to a 2022 NASA study. The fine powder that sits on the moon's surface stuck to their suits and vehicles and even got inside their spacecraft.

Peggy Whitson, an astronaut who has spent 675 days in space, previously told BI that the Apollo missions "had a lot of problems with dust."

"If we're going to spend long durations and build permanent habitats, we have to figure out how to handle that," Whitson said.

There's also a problem with sunlight and deadly solar radiation.

For about 14 days at a time, the side of the moon facing Earth is a boiling hellscape that is exposed directly to the sun's harsh rays; the moon has very little atmosphere, and therefore no protection against solar radiation.

The next 14 days that same side is in total darkness, dipping to temperatures below minus 200 degrees Fahrenheit, making the moon's surface one of the colder places in the solar system.

NASA is developing a fission power system that could supply astronauts with electricity during weekslong lunar nights — which would also be useful on other worlds, including Mars.

"There is not a more environmentally unforgiving or harsher place to live than the moon," the astronautical engineer Madhu Thangavelu wrote. "And yet, since it is so close to the Earth, there is not a better place to learn how to live away from planet Earth."

NASA has designed dust- and sun-resistant spacesuits and rovers, though it's uncertain whether that equipment is anywhere near ready to launch.

"I already knew going to the moon was hard," Reid Wiseman, the Artemis II mission commander, said at a press conference in 2023. "But boy, it's harder than I thought."

A generation of billionaire 'space nuts' may get there

Another issue, astronauts say, is NASA's graying workforce. In 2019, more American kids polled said they dreamed about becoming YouTube stars than astronauts.

"You've got to realize young people are essential to this kind of an effort," the Apollo 17 astronaut Harrison Schmitt previously told BI. "The average age of the people in Mission Control for Apollo 13 was 26 years old, and they'd already been on a bunch of missions."

An estimated 14% of NASA's workforce is over 40 years old, according to a Zippia analysis.

"That's not where innovation and excitement comes from. Excitement comes from when you've got teenagers and 20-year-olds running programs," Rusty Schweickart, a former NASA astronaut, said. "When Elon Musk lands a [rocket booster], his whole company is yelling and screaming and jumping up and down."

Musk is part of what retired astronaut Jeffrey Hoffman has called a "generation of billionaires who are space nuts," developing a new, private suite of moon-capable rockets.

"The innovation that's been going on over the last 10 years in spaceflight never would've happened if it was just NASA and Boeing and Lockheed," Hoffman told journalists during a roundtable in 2018. "Because there was no motivation to reduce the cost or change the way we do it."

Hoffman was referring to the innovative work of Musk's rocket company, SpaceX, as well as to Jeff Bezos, who founded the aerospace company Blue Origin.

"There's no question: If we're going to go farther, especially if we're going to go farther than the moon, we need new transportation," Hoffman added. "Right now we're still in the horse-and-buggy days of spaceflight."

Many astronauts' desire to return to the moon aligns with Bezos' long-term vision. Bezos has floated a plan to start building the first moon base using Blue Origin's New Glenn rocket system. 

"We will move all heavy industry off of Earth, and Earth will be zoned residential and light industry," he said in April 2018.

Musk has also spoken at length about how SpaceX's Starship launch system could pave the way for affordable, regular lunar visits.

"My dream would be that someday the moon would become part of the economic sphere of the Earth — just like geostationary orbit and low-Earth orbit," Hoffman said. "Space out as far as geostationary orbit is part of our everyday economy. Someday I think the moon will be, and that's something to work for."

SpaceX successfully launched its complete Starship system in October.

It was a huge feat, proving the reusable rocket could launch toward space and safely come back to Earth.

With space enthusiasts, both public and private, making strides, astronauts don't doubt whether we'll get back to the moon and onto Mars. It's just a matter of when.

"I guess eventually things will come to pass where they will go back to the moon and eventually go to Mars — probably not in my lifetime," said 96-year-old retired astronaut Jim Lovell, who flew to the moon on Apollo 8 and Apollo 13. "Hopefully, they'll be successful."

• This story was originally published on July 14, 2018. It has been updated. 
• Correction: February 27, 2024 — An earlier version of this story misstated the size of NASA's contract with Intuitive Machines. It was $118 million, not $118 billion. A prior version of this story also misstated the number of moonwalkers. During NASA's Apollo program, 12 people landed on the moon.

{https://www.msn.com/en-us/ }

14-11-2024 om 21:49 geschreven door peter  

Researchers find strong evidence for “Snowball Earth” theory

Study “presents the first physical evidence that Snowball Earth reached the heart of continents at the equator” says lead author Liam Courtney-Davies.

A new study published in the Proceedings of the National Academy of Sciences presents strong evidence that massive glaciers covered the entire globe during the Cryogenian Period, including thick ice sheets that likely formed over Colorado. Led by the University of Colorado Boulder, the research focuses on the Front Range of Colorado's Rocky Mountains, where geologists found physical evidence related to the Snowball Earth hypothesis. The study describes a missing link found in an unusual pebbly sandstone encapsulated within the granite that forms Colorado's Pikes Peak.

Liam Courtney-Davies, the lead author of the study and a postdoctoral researcher in the Department of Geological Sciences at CU Boulder, stated, "This study presents the first physical evidence that Snowball Earth reached the heart of continents at the equator." The discovery that glaciers reached the center of continents, where conditions would have been very dry, deepens the mystery of where and how life survives. Physical evidence that ice sheets covered the interior of continents in warm equatorial regions had eluded scientists until now.

During the Snowball Earth period, around 720 to 635 million years ago, the Earth cooled so much that massive ice sheets encased the entire planet like a giant snowball. Temperatures plummeted, and ice sheets that may have been several miles thick crept over every inch of Earth's surface. Evidence of ice in Colorado dating back 661 million years supports this hypothesis. Scientists believe that ice sheets possibly surrounded the entire planet, even at the equator, where it is warmer today.

Despite decades of research, scientists have not agreed whether the entire globe actually froze during the Snowball Earth period. Initially, geologists were skeptical about finding far more ancient hints of glaciers in tropical regions. It seemed implausible that the planet had ever been cold enough for thick sheets of ice to have reached the equator. The new findings further cement the global Snowball Earth hypothesis, which suggests that this global deep freeze endured for tens of millions of years.

The study focuses on the Tava sandstones, a series of rocks nicknamed the Tavakaiv or "Tava," which hold clues to the frigid period in Earth's past. The Tava rocks are composed of solidified sand injectites, formed when sand-rich fluid was forced into underlying rock, similar to fracking for natural gas or oil. To the untrained eye, the Tava sandstones might seem like ordinary yellow-brown rocks running in vertical bands less than an inch to many feet wide. For geologists, however, they have an unusual history; they likely began as sands at the surface of Colorado at some point in the past.

The researchers used a dating technique called laser ablation mass spectrometry, which zaps minerals with lasers to release some of the atoms inside. Recent advancements in laser-based radiometric dating allowed the researchers to measure the ratio of uranium to lead isotopes in iron oxide minerals, revealing how long ago the individual crystals formed. This allowed them to figure out an age bracket for the sand injectites, which must have formed between 690 million and 660 million years ago, during the Cryogenian Period.

The group suspects that thick ice sheets formed over Colorado during the Snowball Earth period, exposing the sands to intense pressures. The researchers envision the following scenario for how the sand injection happened: A giant ice sheet with areas of geothermal heating at its base produced meltwater, which mixed with quartz-rich sediment below. Similar to fracking for natural gas or oil today, the pressure cracked the rocks and pushed the sandy meltwater in, eventually creating the injectites seen today.

Liam Courtney-Davies says, "These are classic geological features called injectites that often form below some ice sheets, including in modern-day Antarctica." He added, "You have the climate evolving, and you have life evolving with it. All of these things happened during Snowball Earth upheaval." The researchers argue that mineral veins injected into sandstones are a sure sign of a combination of glacial pressure and geothermal heating.

At the time of the Snowball Earth period, Colorado rested over the equator as a landlocked part of the ancient supercontinent Laurentia, and the Tava rocks found on Pikes Peak would have formed close to the equator. If glaciers formed in Colorado, scientists believe they could have formed anywhere on Earth. The Colorado sites fit the criteria of being tropical, low altitude, and far from continental margins at the relevant time.

Rebecca Flowers, co-author of the study and professor of geological sciences at CU Boulder, said, "We're excited that we had the opportunity to unravel the story of the only Snowball Earth deposits that have so far been identified in Colorado." The discovery provides crucial evidence supporting the idea that the entire planet may have been encased in ice.

The findings also have implications for understanding the history of life on Earth. Before the Cryogenian period, life on Earth was dominated by single-celled organisms. After Snowball Earth thawed, the earliest examples of large organisms appeared during the Ediacaran period, which lasted from 635 to 541 million years ago. Scientists still don't understand the processes which led to this explosion in life after Snowball Earth.

Liam Courtney-Davies emphasized the importance of the study, saying, "We have to better characterize this entire time period to understand how we and the planet evolved together." He added, "If such features formed in Colorado during Snowball Earth, they probably formed in other spots around North America, too." The researchers hope that the secrets of these elusive Cryogenian rocks in Colorado will lead to the discovery of further terrestrial records of Snowball Earth.

Such findings can help develop a clearer picture of Earth during climate extremes and the processes that led to the habitable planet we live on today. The researchers' results support that a Great Unconformity near Pikes Peak must have been formed prior to Cryogenian Snowball Earth. This finding is at odds with hypotheses that attribute the formation of the Great Unconformity to large-scale erosion by Snowball Earth ice sheets themselves.

Ultimately, the study not only sheds light on a critical phase in Earth's geologic history but also deepens the mystery of where and how life survives during extreme climate events. The researchers' work underscores the interconnectedness of Earth's climate and the evolution of life, providing new avenues for exploration and understanding.

Sources:

• Science Alert,
• Cosmos,
• Phys.org,
• IFLScience,
• Science Daily

This article was written in collaboration with generative AI company Alchemiq

{ https://www.jpost.com/ }

14-11-2024 om 21:19 geschreven door peter  

Mars has been a fascination to us for centuries. Early observations falsely gave impressions of an intelligent civilisation but early visiting probes revealed a stark, desolate world. Underneath the surface is a few metres of water ice and a recent study by NASA suggests sunlight could reach the layer. If it does, it may allow photosynthesis in the meltwater. On Earth this actually happened and biologists have found similar pools teeming with life. 

The exploration of Mars by space probes began in the 1960’s. It began with the Soviet Union Mars 1 and NASA’s Mariner mission and was soon followed by the well known Viking landers in 1976. They were the first missions to test surface material for signs of life. The Mars Pathfinder mission took along the Sojourner rover and was followed by Spirit and Opportunity rovers after the turn of the century. Curiosity rover was among the latest of the visitors along with Perseverance and China’s Tianwen-1. The focus of later missions has been the hunt for water and analysis of the climate and geology of the planet. This was not only to understand the conditions as the planet evolved but to pave the way for human exploration. 

To date, there has been no evidence of life on Mars. The question has intrigued us for decades though. Of all the planets in the Solar System, Mars is the most likely place to have once harboured primitive life, chiefly due to the discovery of liquid water in the distant past. Evidence of ancient dried river beds has been found across the planet with mineral deposits indicating that Mars was once warmer, wetter and potentially far more habitable. Even organic molecules have been discovered by the Curiosity and Perseverance rovers but researchers continue to hunt for evidence (past or present) of microbial life. 

A team of researchers from NASA have published a paper articulating their use of computer modelling to help the search. They have shown that sunlight can shine through the Martian water ice, perhaps even enough for photosynthesis to occur in shallow pools of meltwater. 

There are two types of ice on Mars, frozen water and frozen carbon dioxide. The study explored water ice which had mostly formed as snow had fallen on the surface during a Martian ice age millions of years ago. The team believe that the key to the study are the dust particles that obscure light reaching the deeper layers of ice. They suggest that sunlight will warm the dark dust more than surrounding ice and then cause ice to warm and melt. Some scientists believe that ice at the surface cannot melt due to the thin dry atmosphere causing it to turn straight to a gas. This won’t apply to the ice deeper in the surface layer. 

Such a process has been observed on Earth where dust heats ice, melts and allows the dust to sink. Over time, the dust particles will stop sinking through the ice but still generate enough heat to melt the ice and create tiny voids. It is here that thriving ecosystems have been found hosting simple forms of life. 

The paper published in Nature Communications Earth & Environment, suggests the dusty ice can produce enough light at depths up to 3 metres to allow photosynthesis to occur. The subsurface pools of meltwater are protected from evaporating by the ice above. It also provides some protection from radiation too providing a possibly habitable environment for simple forms of life. The authors suggest the areas would likely form in the Martian tropics between 30 and 60 degrees latitude in both hemispheres. 

Source : 

• Could Life Exist Below Mars Ice? NASA Study Proposes Possibilities

{ https://www.universetoday.com/ }

14-11-2024 om 14:54 geschreven door peter  

• READ MORE: Doctors raise concerns about Sunita Williams' health on the ISS

By STACY LIBERATORE FOR DAILYMAIL.COM

The stranded NASA astronaut at the center of growing health fears has finally broken her silence in a video recorded from space.

Health experts and NASA insiders had raised concerns that Sunita Williams, 59, was rapidly losing weight after photos appeared to show her looking 'gaunt' earlier this month, after spending over 150 days stuck on the International Space Station. 

But Williams hit back at the 'rumors' in a live video published by NASA today, claiming that she has actually put on muscle. 

'My thighs are a little bit bigger, my butt is a little bit bigger. We do a lot of squats,' she said.

She added that she is the same weight as when she launched to the ISS in June, and bizarrely claimed the apparent change in her appearance was due to 'fluid shift.'

'I think things shift around quite a bit, you probably heard of a fluid shift,' Williams said.

'Folks in space you know, their heads look a little bit bigger because the fluid evens out along the body.'

During spaceflight, weightlessness instantly shifts blood and fluids from the lower portion of the body to the upper areas, which can sometimes result in a puffy pace and thinner legs.

NASA astronaut Sunita Williams has broken her silence about fears that her health has deteriorated since becoming stranded on the International Space Station (ISS)

The health concerns surface when a photo from September appeared to she her with 'sunken' cheeks and a thinner frame 

Williams and her crewmate Barry Wilmore, 61, have been living on the ISS for five months after Boeing's faulty Starliner spacecraft was deemed unsafe to return them to Earth.

The mission was initially only supposed to be eight days but the astronauts won't return until February 2025. 

Williams spoke with the New England Sports Network Clubhouse Kids Show Tuesday while more than 250 miles above Earth's surface. 

During the interview, she addressed health concerns, calling them 'rumors,' and discussed her food intake, such as dining on a Turkish fish stew with olives and rice.

Williams did not provide details about her caloric intake while aboard the ISS.

A photo taken September 24 initially sparked health fears. A doctor told DailyMail.com at the time her cheeks looked 'sunken', possibly as a result of rapid weight loss.

Dr Vinay Gupta, a pulmonologist and veteran in Seattle, told DailyMail.com at the time that although she did not seem at a place where her life was in danger, 'I don't think you can look at that photo and say she has sort of healthy body weight.' 

More recently, a NASA source told the New York Post that NASA has been scrambling to 'stabilize the weight loss and hopefully reverse it.'

The unnamed employee who is 'directly involved with the mission' said that Williams has been 'unable to keep up with the high-caloric diets that astronauts must consume' while on the ISS. 

'The pounds have melted off her and she's now skin and bones. So it's a priority to help her stabilize the weight loss and hopefully reverse it,' the NASA source told the New York Post.

Sunita Williams and Barry Wilmore before their mission on June 5. Williams said that she is the same weight now as she was at launch

Williams did not touch on her caloric intake while on the ISS, but alluded that she was eating well 

Williams and Wilmore still have to wait about three to four months until they can return to Earth on SpaceX's Crew Dragon.

At this time, there is no evidence to suggest that Williams' alleged health decline will impact this timeline.

But the female body suffers more in space than their male counterparts.

A study assembled by NASA in 2014 found that women have greater loss of blood plasma volume than men during spaceflight, and women’s stress response characteristically includes a heart rate increase while men respond with an increase in vascular resistance.

Read More

• The frightening amount of radiation NASA's stranded astronauts have endured because of Boeing's faulty spaceship 

The loss of blood plasma causes your metabolic rate to temporarily increase while your body mobilizes resources to adjust to the loss of plasma.

And this response can slightly elevate your calorie burn, resulting in weight loss similar to what Williams may be experiencing.

Another study released by Ball University in 2023 also found that women lose more muscle than men in a microgravity environment such as spaceflight.

'The amount of oxygen in the air is lower than it is at baseline, their nutritional intake is not going to be as robust as can be on the ground,' said Dr Gupta.

'Their ability to work out is going to be limited. So every every sort of physiologic variable that defines our well being is going to be suboptimal, especially even in a pressurized cabin, but in, you know, in outer space in their case, right?

'So what you're seeing there in that picture, especially with Sunita, is somebody that I think is experiencing the natural stresses of living at very high altitude, even in a pressurized cabin, for extended periods.'

{ https://www.dailymail.co.uk/ }

13-11-2024 om 21:00 geschreven door peter  

(Credit: NASA/JPL-Caltech).

The new findings could improve the chances of life having once existed on Mars, as well as the likelihood that additional evidence for it may be uncovered during current investigations at promising sites like Jezero Crater, where NASA’s Perseverance rover is currently conducting studies.

Harsh Living Conditions

The cold, dry conditions on Mars right now make it an unlikely place for organisms to be able to thrive, and a demanding place for humans who may undertake extended missions there in future decades.

Yet geological evidence suggests that this might not have been the case in the distant past. Around 3.7 million years ago, Mars may have possessed liquid water and an environment in which at least simple organisms could have thrived.

According to the Tohoku University team, formaldehyde might have also formed during this period of relative habitability on Mars. This is significant because formaldehyde is an important precursor in the formation of biomolecules through abiotic processes.

Modeling Early Mars

The Tohoku University team employed a computer model that allowed them to simulate conditions on the Red Planet long ago and see whether the formation of formaldehyde seemed likely based on the premise that the atmosphere then would have had an abundance of carbon dioxide, hydrogen and carbon monoxide.

Based on their simulations, Mars would have had an atmosphere 3.6 to 2.8 billion years ago that could have provided enough formaldehyde to allow several different organic compounds to form. This is significant since it means there is a chance that organic materials found on Mars could have had atmospheric origins during the earliest geological periods on the planet.

Shungo Koyama, the lead author of a new study outlining the team’s research, says their findings offer potentially groundbreaking insights into what chemical processes might have been occurring on Mars in the past, which provide a clearer picture of the conditions there that might have been conducive to life long ago.

Building Blocks of Life

“Our results show that a continuous supply of atmospheric [formaldehyde] can be used to form various organic compounds, including amino acids and sugars,” the team writes in the paper, offering a potential origin for its presence on the Martian surface.

With formaldehyde’s conversion into ribose, the team reports that “a continuous supply of bio-important sugars on early Mars, particularly during the Noachian and early Hesperian periods,” seems plausible.

Future studies by the team aim to explore geological data NASA’s rovers have collected to find additional clues about the presence of organic molecules on ancient Mars, and compare their models with samples obtained from the planet.

The team’s recent study, “Atmospheric formaldehyde production on early Mars leading to a potential formation of bio-important molecules,” was published in Scientific Reports.

VIDEOS

• Micah Hanks is the Editor-in-Chief and Co-Founder of The Debrief. He can be reached by email at micah@thedebrief.org. Follow his work at micahhanks.com and on X: @MicahHanks.

{ https://thedebrief.org/ }

13-11-2024 om 20:38 geschreven door peter  

Watch this private Varda Space capsule's blistering return to Earth in amazing onboard video

13-11-2024 om 18:23 geschreven door peter  

Scientists propose a shocking new theory for the origin of the moon - and claim the popular 'collision theory' is WRONG

• READ MORE: Our moon went through physical changes during Covid 

By WILIAM HUNTER

Despite being our planet's closest neighbour, scientists have been grappling with the mystery of our moon's origin for hundreds of years. 

Since the 1980s, experts have assumed that our lunar satellite was formed in the aftermath of an explosive impact with the protoplanet Theia early in Earth's history.

But now, a study suggests that this so-called 'collision' theory may not be correct after all.

Instead, researchers from Penn State University say that the Earth might have neatly nabbed the moon as it drifted by in a process called binary-exchange capture.

This radical theory suggests that the moon might have started life as one part of a 'terrestrial binary', a pair of rocky objects orbiting one another.

As this pair passed within Earth's pull, the moon was yanked into orbit while the second body was catapulted out into space.

Lead researcher Professor Darren Williams says: 'No one knows how the moon was formed.

'For the last four decades, we have had one possibility for how it got there. Now, we have two.'

A new theory suggests that the moon might not have been formed by a collision with  an ancient protoplanet but through a process called 'binary-exchange capture'  

Researchers suggest that the moon might have started out as one part of a planetary binary, two large rocky bodies which orbit each other as they drift through space (file photo)

In 1984, scientists gathered for the Kona Conference in Hawaii to come to a consensus on how the moon had formed.

Using the 800lbs (363kg) of lunar material taken back by NASA's Apollo missions, the scientists found that the moon had a similar but not entirely identical chemical composition to Earth.

From this evidence, they came to the conclusion that the moon must have been formed out of debris knocked loose when a celestial body slammed into the young Earth.

This theory was popular because it fits well with much of what we now know about the chemical composition of the moon - but it doesn't explain all the details.

For example, Professor Williams and his co-author point out that, if the moon were formed from a ring of debris slowly condensing into a sphere, we should expect to find it orbiting above the equator.

However, the moon's orbit is actually tilted onto a totally different plane about seven degrees away from the equatorial plane. 

To find an alternative explanation for why this might be the case, the researchers looked at a phenomenon called binary-exchange capture.

This suggests that Earth might have snagged one of a pair of passing rocky bodies and made it into its satellite.

Earlier theories suggest that the moon was formed when a protoplanet called Theia collided with the young Earth. Scientists believe the moon was formed as the resultant ring of debris collected into a sphere 

The binary-exchange capture theory

The moon may have started out as one part of a 'planetary binary', two rocky bodies orbiting each other as they drift through space.

As this binary entered Earth's gravitational pull, the moon might have been yanked out of the binary pair.

The moon would then become the Earth's satellite while the other part of the pair was catapulted into space.

This would explain why the moon doesn't orbit over the equator as we would expect from a collision.

It also provides a reason why the moon is chemically similar to, but not identical to Earth.

In support of this idea, Professor Williams points to the example of Triton, Neptune's largest moon.

Current theories suggest that Triton was pulled into Neptune from the Kuiper Belt where one in 10 objects are thought to be a binary.

Just like our moon, Triton orbits at a significantly tilted angle, leaning 67 degrees away from the planet's equator.

And, according to mathematical models, it is quite plausible that the same thing could have happened to our moon.

In their paper, published in The Planetary Science Journal, the researchers calculate that Earth could have captured an object between one and 10 per cent of its total mass.

At just 1.2 per cent of the Earth's mass, the moon falls comfortably within this range.

The only caveat is that the planetary binary would have had to have passed within just 80,000 miles (128,750km) of Earth at a speed below 6,700 miles per hour (10,800km).

While that might seem incredibly fast, in the scale of the solar system that is the equivalent of a leisurely stroll.

Researchers point out that if the moon were formed from a collision we should expect it to orbit Earth around the equator. But the moon's orbital plane is angled at about 7 degrees from the equator 

Using a mathematical model (pictured), the scientists calculated that the Earth could capture an object between one and 10 times its mass if it was travelling at the right speed and the other part of the binary had a large enough mass. As this graph shows, the Earth is easily capable of capturing something as large as the moon at speeds of up to 3km per second 

The problem is that, even at these sedate speeds, when it first arrived, the moon's orbit would have been massively elliptical much like that of a comet around the sun.

However, the researchers also show how this orbit would have evolved under the influence of tidal forces.

As the moon races around the Earth, the tides would have slightly lagged behind its orbit, exerting a gravitational pull which would have slowly tamed its wild orbit.

Over thousands of years, that constant tug would have made the orbit more regular and circular until it settled into the close orbit it currently has.

Professor Williams says: 'Today, the Earth tide is ahead of the Moon, high tide accelerates the orbit.

'It gives it a pulse, a little bit of boost. Over time, the Moon drifts a bit farther away.'

Now the moon is so far out that both the Sun and Earth pull on it, leading it to drift about 3cm further away every year.

This theory has some key advantages in that it explains why the moon's orbit is so tilted and accounts for the presence of certain chemical isotopes found on the moon and not on Earth.

Scientists believe that Triton (pictured), the largest moon of Neptune, was originally a planetary binary in the Keuper belt before being captured 

As this graph shows, when the moon first arrived, its orbit would be shaped like an oval rather than the circle we are more familiar with 

The researchers admit that their theory would be hard to prove and relies on several 'implausible events' happening at once.

However, Professor Williams maintains that binary-exchange capture is a viable alternative to the standard collision theory and one that merits further consideration.

The researchers argue that planetary binaries may have been more common in the early solar system and could have plausibly gone on to create the moon. 

Professor Williams adds: 'This opens a treasure trove of new questions and opportunities for further study.'

{ https://www.dailymail.co.uk/ }

12-11-2024 om 23:49 geschreven door peter  

NASA's ice-hunting VIPER moon rover getting ready to slither to the launch pad

Moon-orbiting satellite missions have collected data regarding water on the moon before, but VIPER will get "up close and personal" with the lunar surface, scanning with its scientific tools and investigating soil at varying depths with its 3.3-foot (1 meter) drill. Some of the regions VIPER will explore are permanently shadowed craters that are some of the coldest places in the solar system. It is believed that the bottoms of these craters harbor ice that has been undisturbed for billions of years.

As it conducts its mission, VIPER will be exposed to the extreme environment of the moon and the incredibly cold temperatures of these permanently shadowed areas while having to overcome complex terrain.

Testing of VIPER's systems is a crucial stage for the mission. Andrews explained that, as the team assembles and installs various subsystems onto the rover, they perform "channelization" tests. These trials enable the team to confirm that pieces and parts like cable harnesses and connectors between systems are working. 

"Now, you might think, 'Of course what we installed should work!' But it’s important to remember how complicated these space systems, and planetary rover systems in particular, are," Andrews said. "Sometimes we will perform even more complex tests, like sending a command to the Near Infrared Volatile Spectrometer Subsystem (NIRVSS) instrument to take an image: Is the image taken successful? Is the field of view of the image correct? Did the image make its way into the rover’s avionics for downlink?"

This "test as we go" approach ensures that the NASA team doesn't discover issues that could impact VIPER later in its development or, even worse, when it is unreachable on the lunar surface. 

"So we test as we go to decrease risk later when we’re performing whole-rover environmental tests. This way, if the rover doesn’t work as expected after one of VIPER’s environmental tests, we know it once worked fine, and that can help us more quickly problem-solve what might have gone wrong," Andrews concluded. "The pace in which we’ve been working through the build and subsystem checkouts has been blistering lately, and we’ve had a good run of successes.

"Go VIPER!"

VIDEOS

{ https://www.space.com/ }

12-11-2024 om 20:58 geschreven door peter  

'Otherworldly' crash site discovered on surface of Mars by NASA helicopter

Sinead Butler

An "otherwordly" crash site of another spacecraft was photographed by a NASA helicopter.

Back in 2020, the Perseverance Rover was sent up to the Red Planet with the Mars Helicopter called Ingenuity strapped to the bottom of it.

The initial plan was for Ingenuity - otherwise known as Ginny - to make no more than five test flights within 30 days but in the end, the aircraft surpassed expectations when it completed 72 flights between April 2021 and January 2024.

It's more impressive when you consider the fact that the helicopter was just half a meter (1.6 feet) tall and weighed less than two kilograms (four pounds).

As the first aircraft to successfully complete a powered, controlled flight on another planet, the purpose of the flights was to explore parts of Mars that couldn't be reached by the Perseverance rover.

NASA/JPL-Caltech

One of the notable aerial images was captured in 2022 when the helicopter took photos of debris on the dusty, cold, desert.

"There's definitely a sci-fi element to it. It exudes otherworldly, doesn't it?" Ian Clark, a Perseverance parachute system engineer, told The New York Times.

“They say a picture's worth 1,000 words, but it's also worth an infinite amount of engineering understanding.”

But before you go and make assumptions that Martians or alien life were responsible for the wreckage, this wasn't the case but rather was the result of us humans.

So what was the debris?

Basically, it was landing equipment used to help Ingenuity and the Peersererance Rover land on the surface of Mars in 2021.

In the photos, you can see the upright backshell and the debris which is thought to have impacted the surface at about 78 mph (126 kph).

“The backshell’s protective coating appears to have remained intact during Mars atmospheric entry. Many of the 80 high-strength suspension lines connecting the backshell to the parachute are visible and also appear intact," the space agency said.

“Spread out and covered in dust, only about a third of the orange-and-white parachute - at 70.5 feet (21.5 meters) wide, it was the biggest ever deployed on Mars - can be seen, but the canopy shows no signs of damage from the supersonic airflow during inflation.”

{ https://www.indy100.com/ }

12-11-2024 om 17:28 geschreven door peter