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NASA Astronomers Classify Near-Earth Asteroids: Latest Findings – Sciworthy

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Researchers exploring the solar system’s history focus on a diverse range of comets and asteroids, particularly those classified as Near-Earth Objects (NEOs). These celestial bodies not only offer insights into the origins of water and organic materials but also continue to impact planets across the solar system, including Mars, Earth, Venus, and Mercury. Their close proximity to Earth facilitates detection and observation with smaller telescopes, increasing the potential for successful interceptions, potentially involving rovers and landers.

An international research team has recently classified and identified 39 new NEOs between February 2021 and September 2024, utilizing two advanced telescopes: Itaparica Observatory (OASI) in Brazil, along with the 2.15-meter Jorge Sahade telescope at Complejo Astronomico El Leoncito (CASLEO) in Argentina.

The research team used these telescopes to study variations in the brightness of NEOs over time. Since NEOs are essentially blocks of ice or rock that reflect sunlight rather than emit light, their visibility from Earth is influenced by the angle between Earth and the Sun along with their size, shape, and structure. By measuring the periodic changes in brightness, scientists calculated the rotation rates of these objects.

The diameters of the 39 NEOs varied from 0.1 to 10 kilometers (0.06 to 6 miles), with most ranging between 0.5 to 3 kilometers (0.3 to 2 miles). Their shapes ranged from nearly spherical to elongated, cigar-like forms. The team successfully determined the rotation periods for 26 of these NEOs, noting that the shortest rotation cycle was just over two hours while the longest approached 20 hours. Notably, 16 of these NEOs rotated in under 5 hours, suggesting that many are fast-rotating bodies.

The study established that a rotation period exceeding 2.2 hours is the upper limit for small NEOs known as rubble pile asteroids, which are loose formations held together by self-gravity. Beyond this threshold, centrifugal forces could destabilize them. Conversely, those NEOs under 250 meters (820 feet) tend to be more solid, dubbed monoliths. The findings indicated that smaller and medium-sized NEOs exhibit varied structures and formation histories.

Using advanced imaging techniques through telescope lenses that filter specific light wavelengths, the researchers analyzed the chemical composition of 34 NEOs. They employed 2 additional filters alongside 4 filters designed for green and red wavelengths, including near-infrared wavelengths. Their results revealed that 50% of the NEOs are silica-based, resembling many terrestrial rocks, with 23.5% comprising carbon-rich materials, approximately 9% metals, and around 6% basaltic elements. The remaining composition was a mixture of carbon and silicates as well as calcium and aluminum.

While the chemical analysis largely aligned with previous findings, the researchers found a lack of olivine—a mineral typically prevalent in smaller asteroids. This absence can be attributed to the fact that most sampled NEOs exceeded 200 meters (660 feet), surpassing the typical size for olivine-rich asteroids.

This research enriches our understanding of NEOs and their physical and chemical properties. The team advocates for an integrated research approach that leverages technology and multi-telescope observations to effectively characterize small celestial objects. Future studies should prioritize close monitoring of NEOs, especially those approaching their rotation threshold, and employ radar observations to confirm the existence of potential binary pairs. By analyzing reflected visible and near-infrared light, researchers can further unveil the chemical makeup of the asteroid surfaces.


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Webb’s Observations Indicate That Asteroids Bennu and Ryug Belong to the Polana Collision Family

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New Polana Collisional Family The primary asteroid belt in our solar system is the source of insights about nearby asteroids (101955) Bennu and (162173) Ryugu, which are the focus of NASA’s Osiris Rex missions. Currently, astronomers utilizing the NASA/ESA/CSA James Webb Space Telescope are gathering spectroscopic data from the family progenitor, (142) Polana, and comparing it to laboratory data from both spacecraft and near-Earth asteroids, revealing near-infrared spectral similarities that lend support to the hypothesis that they originated from the same protoplanetary body.

This image of this asteroid was captured on June 26, 2018 by Jaxa’s Hayabusa-2 Spacecraft optical navigation camera – telescopic (ONC-T). Image credits: Jakusa / University of Tokyo / Kochi University / Ricchiho University / Nagoya University / Chiba University of Technology / Nishimura University / Aizu University / AIST.

“We hypothesize that in the early formation of our solar system, a significant asteroid collided and broke apart, creating the Polana and the ‘Asteroid Family,’ the largest remaining body,” stated Dr. Anisia Aredondo, a researcher at the Southwest Research Institute.

“This theory posits that the remnants of that collision led to the formation of not just Polana, but also Bennu and Ryugu.”

“To validate this theory, we began analyzing the spectra of all three entities and comparing them.”

The researchers used time on Webb to observe Polana with two different spectral instruments targeting near-infrared and mid-infrared wavelengths.

The data was then contrasted with spectral information from physical samples of Ryugu and Bennu collected by two distinct space missions.

“Bennu and Ryugu are categorized as near-Earth asteroids as they orbit the Sun within Mars’ orbit,” they noted.

“However, they pose no threat to our planet, with closest approaches of approximately 3 million km (1.9 million miles) and 1.6 million km (1 million miles), respectively.”

“Bennu and Ryugu are relatively small compared to Polana; Bennu measures about 500 m in diameter (0.3 miles), while Ryugu is twice as large, but both Polana and Ryugu measure about 55.3 km (34.4 miles) wide.”

“Scientists believe that Jupiter’s gravity caused Bennu and Ryugu to drift out of their orbit near Polana.”

“Given their similarities, I am confident all three asteroids share a common parent,” she added.

This mosaic image of the asteroid Bennu consists of 12 images collected on December 2, 2018 by a 15-mile (24 km) Polycam instrument at Osiris-Rex. Image credit: NASA/NASA’s Goddard Space Flight Center/University of Arizona.

The authors indicate that while spectral data from the asteroids exhibit variations and discrepancies, they do not sufficiently invalidate the hypothesis that they all have a shared origin.

“Polana, Bennu, and Ryugu have been traversing their respective paths through our solar system since the collision that may have formed them,” remarks Dr. Tracy Becker from the Southwest Research Institute.

“Bennu and Ryugu are now much closer to the Sun compared to Polana, resulting in their surfaces being more influenced by solar radiation and solar particles.”

“Additionally, Polana is likely older than Bennu and Ryugu, and as such, has been subjected to impact from micrometeorites over an extended period.”

“This could potentially alter the surface areas containing their elemental compositions.”

A study detailing the survey results has been published in the Journal of Planetary Science.

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Anisia Aredondo et al. 2025. Planet. Sci. J. 6, 195; doi:10.3847/psj/ade395

Source: www.sci.news

Vera Rubin Observatory Uncovers Thousands of New Asteroids

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https://www.youtube.com/watch?v=qgq2lcpkifg

Countless unique asteroids traverse the solar system, amidst millions of distant stars and galaxies captured in the inaugural images released by the Vera C. Rubin Observatory.

“These stunning galaxies were photogenically disrupted by asteroids,” noted Željko Ivezić during a press briefing on June 23rd at Washington University in Seattle, presenting images that showcase several asteroids zipping past two spiral-armed galaxies.

Within just 10 hours of observing the night sky, the telescope, positioned in the pristine atmosphere atop a mountain in the Chilean desert, detected 2,104 previously unknown asteroids. Among these, seven have trajectories that come close to Earth, yet none poses a threat, according to Ivezic.

Researchers identified and tracked newly discovered asteroids in images taken over 10 hours

NSF-DOE VERA C. RUBIN OBSERVATORY

Although telescopes are not primarily designed to detect near-Earth objects, they are intended for a comprehensive study of the universe over a decade. However, their features are also conducive to spotting asteroids. “You need to survey the sky rapidly with a vast field of view,” Ivezic explained.

Asteroids were identified by scrutinizing areas of the sky and noting what was in motion. In the composite image shown by Ivezić during the briefing, the asteroids appeared as colored streaks against the backdrop of brighter objects in deeper space. This enhances our understanding of the neighboring celestial bodies. “We weren’t surprised,” he said. “There’s an impressive simulation.”

Throughout a decade-long research initiative, the telescope is anticipated to identify around 5 million new asteroids, surpassing the total discovered in previous centuries.

Asteroids are marked with a colored dot in front of an image of a galaxy visible in the southern sky

NSF-DOE VERA C. RUBIN OBSERVATORY Copyright: NSF-DOE VERA C. Rubin Observatory

The new detections are reported daily to the US Minor Planet Center, which analyzes orbital paths and identifies objects that could threaten Earth. “In under 24 hours, the world will be informed about potentially hazardous objects,” Ivezic stated.

Matthew Payne from the Minor Planet Center remarked that it’s estimated only 40% of close Earth objects capable of posing a threat have been discovered. An exponential increase in detections from the Vera Rubin Observatory will hasten the identification of the remaining objects.

A substantial rise in observations of other solar system entities—from main belt asteroids between Mars and Jupiter to objects further out beyond Neptune—is anticipated to offer fresh insights into our immediate cosmic neighborhood. “It’s expected to truly revolutionize solar system science,” Payne concluded.

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Source: www.newscientist.com

The evolving probability of asteroids striking Earth in 2032

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Asteroids flying near Earth in 2032 are expected to safely pass through the planet, with a shock chance of just 0.004%. NASA said Monday.

This is a significant downgrade to the risk from the record highs the space agency gave earlier last week.

The asteroid known as the 2024 YR4 is between 130 and 300 feet wide and is large enough to cause local damage if it hits Earth. However, the exact odds of the event have been an impressive target since the space rock was first detected about two months ago.

The extremely slim chances NASA estimated on Monday were even smaller than the 0.28% chance it gave late last week. Just a few days ago, the agency had the chance to 1.5% and 3.1% before that.

With the short odds exceeded 3%, the first object officially classified as Level 3 of 10 out of 10 in a measurement known as the Torino Scale became the space rock. Richard Binzel first proposed it nearly 30 years ago.

Level 3 classification means that objects are worthy of attention by astronomers, and pose a threat of “close encounters.”

Named after an Italian city officially adopted by astronomers In 1999, the Turin Impact Hazard Scale is a way to communicate to the public the risks posed by asteroids and other space objects near Earth to planets.

The scale is color-coded, with categories ranging from 0 (white without risk) to 10 (red for a particular collision). With a 3.1% chance of colliding with the Earth, 024-year-old 4 was temporarily placed in the mid-yellow zone of the scale.

The gusts of news reports about the asteroids have attracted more attention than ever on Turin's scale. Binzel said this type of situation was exactly why he created the system in the first place.

“The Massachusetts Institute of Technology has made it a great opportunity to learn about the world,” said Bindel, a professor of planetary science at the Massachusetts Institute of Technology. “But it's like being between a rock and a difficult place because we want to report what we know to maintain the trust of our people, but we don't want to raise unnecessary anxiety. Because.”

The challenges of walking that thin line are revealed in Asteroid 2024 YR4.

According to NASA, the reason for the recent decline in impact probability is The ground telescope was able to get a better look Based on these observations, on the Space Lock on February 19th and 20th, astronomers were able to improve models of asteroid orbits, allowing them to estimate the Space Lock trajectory more accurately. This will help scientists to more reliably predict where 2024 YR4 will be on December 22, 2032, where asteroids are likely to encounter closely with Earth.

The shifting probability is somewhat dizzy, but according to Bindsel, the possibility that such a close-Earth asteroid could dance like this is completely normal.

The Asteroid 2024 YR4 is thought to measure up to 300 feet in diameter.Atlas

When Binzel debuted the Turin scale in the astronomical community decades ago, his goal was to promote greater public awareness of shock risk. According to him, the idea was to implement something similar to the Richter scale, which measures the magnitude of an earthquake, or the Saffir Simpson scale, which assigns categories to hurricanes based on wind speed.

But when he first presented the system at the 1997 UN conference, it wasn’t well received, he said. According to Biinsel, some astronomers were skeptical that it would help the public.

In the same year, scientists discovered an asteroid called XF11 in 1997. We thought this could hit Earth in 2028. It didn’t take long for astronomers to eliminate potential conflicts, but the ending story expanded in news reports, followed by subsequent denunciations. Something that was perceived as a major mistake.

“It ended up being a bit of embarrassment,” Binzel said. “Astronomers did not make any errors, but there was no good way to convey uncertainty. So this classifies objects that cannot be immediately ruled out over centuries of Earth. This motivated me to propose a simple system for

Binzel once again presented the scale in Turin at a conference held in Turin in 1999, attended by representatives from the NASA and the European Space Agency. In that workshop, the system was ultimately adopted by the International Astronomical Union, a non-governmental organization made up of professional astronomers who act like the governing body of the astronomical community.

In addition to using colours and numbers to accommodate different risk levels, the scale includes explanations of potential outcomes, the possibility of changing risk assessments, and actions that the government or the public should take.

For example, the level 6 threat in the orange zone explains the possibility of close shaving by “large objects pose a serious and uncertain threat of a global catastrophe.”

Astronomers recommend giving this object “critical attention” to know if a collision occurs. “If the encounter is less than 30 years, the government's emergency plan could be guaranteed,” the scale states.

On the other hand, Level 3 threat, according to the scale explanation, means that “current calculations provide more than 1% chance of a collision that can be locally destructive.” “Perhaps observations of the new telescope lead to reallocation to level 0. Attention by civil servants is valuable if the encounter is within ten years.”

Naturally, Binzel was correctly suspected when asteroid 2024 YR4 was considered to be the 3 that would eventually be downgraded.

Meanwhile, however, the 2024 YR4 hit an unpleasant milestone. It is the only known astide with a classification above level 1, and set the record to reach the highest impact probability and spend the longest time with the probability above 1%. According to the European Space Agency.

The higher classification of similar or larger sized asteroids on the Turin scale is in 2004, when asteroid Apophis was temporarily ranked as Level 4, with an estimated 2.7% chance of hitting Earth There was a possibility.

Vincell said he was pleased to witness the scale feature in real time, but he is pleased to be modest about his connection to it.

“At the end of the day, if Turin scale helps, there's a great deal of satisfaction. It really makes my day,” he said. “But it's nice to hide my name behind where the scale was adopted. It helps to keep my phone from ringing too much.”

Source: www.nbcnews.com

Webb finds 138 main belt asteroids measuring 10 meters in diameter

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These asteroids are as small as 10 meters in diameter, making them the smallest asteroids ever observed in the major asteroid belt.

Artist Webb's illustration reveals clusters of main-belt decameter asteroids in infrared light. Image credit: Ella Mall/Julian de Wit.

The discovery of asteroids is essential to planetary defense efforts aimed at preventing collisions with Earth, such as the frequent megaton explosions caused by decameter impactors.

Large asteroids (=>100 km) remain in the main belt since their formation, while smaller asteroids are typically transported into the near-Earth object (NEO) population.

“We were able to detect NEOs very close to Earth, up to 10 meters in size,” said MIT researcher Dr. Artem Brudanov.

“We now have a way to discover these small asteroids when they are far away, so we can do more precise trajectory tracking, which is important for planetary defense.”

For this study, astronomers used data from the NASA/ESA/CSA James Webb Space Telescope to search for small asteroids.

Coincidentally, asteroids orbiting the main asteroid belt are much brighter in infrared wavelengths than in visible wavelengths, making them much easier to detect with Webb's infrared capabilities.

Researchers were able to discover eight known asteroids in the main asteroid belt.

Further investigation subsequently discovered 138 new asteroids around the belt, all within a few tens of meters in diameter, making them the smallest main-belt asteroids ever detected. .

They think several asteroids may be on their way to becoming NEOs, and one of them is probably the Trojans, or Jupiter-tracking asteroids.

“We thought we would only detect a few new objects, but we detected far more objects than we expected, especially small ones,” said Professor Julian de Witt of the Massachusetts Institute of Technology.

“This is an indication that we are exploring a new population regime, where many more small objects are formed by a chain of collisions that very efficiently disintegrates asteroids smaller than about 100 meters. It will be done.”

“This is a completely new and unexplored territory that we are entering, thanks to modern technology,” said Dr. Brudanov.

“This is a great example of what we can do as a field when we look at data from a different perspective. Sometimes the benefits can be huge, and this is one of them.”

“The statistics of these very small main-belt asteroids are very important for modeling asteroid populations,” said Dr. Miroslav Broz, a researcher at Charles University in Prague.

In fact, these are debris ejected during the impact of larger, kilometer-sized asteroids, which are observable and often exhibit similar orbits around the sun, placing them in a “family” of asteroids. Can be grouped. ”

“We never expected that we could use state-of-the-art exoplanet observations to achieve such impactful solar system bonus science,” said Dr. Michael Guillon, a researcher at the University of Liège.

ESA researcher Dr Marco Micheli said: “Thanks to the web, we can now discover these small asteroids even when they are located far from Earth, allowing us to make more accurate orbit determinations. “This is extremely important for planetary defense.” Near Earth Object Coordination Center.

of the team paper Published in today's magazine nature.

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AY Brudanov others. JWST sighting of a 10-meter main belt asteroid and views on the meteorite source. naturepublished online on December 9, 2024. doi: 10.1038/s41586-024-08480-z

Source: www.sci.news

Astrophysicists study planets, asteroids, and primordial black holes in Earth’s matter

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Primordial black holes have been theorized for decades and may even be the eternally elusive dark matter. However, primordial black holes have not yet been observed. These tiny black holes could become trapped in rocky planets or asteroids, consuming their liquid cores from within and leaving hollow structures behind, according to a duo of astrophysicists from the University at Buffalo, Case Western Reserve University, and National Donghua University. It is said that there is. Alternatively, microtunnels could be left in very old rocks on Earth, or in the glass or other solid structures of very old buildings.

An artist's impression of a primordial black hole. Image credit: NASA.

Small primordial black holes are perhaps the most intriguing and intriguing relics of the early universe.

They could act as candidates for dark matter, be sources of primordial gravitational waves, and help solve cosmological problems such as domain walls and the magnetic monopole problem.

However, so far no convincing primordial black hole candidates have been observed.

Professor Dejan Stojković of the University at Buffalo said: “Although the chances of finding these signatures are low, the search does not require many resources and the potential reward of providing the first evidence of a primordial black hole is enormous. It's going to become something.”

“We need to think outside the box because what has been done so far to find primordial black holes has not worked.”

Professor Stojkovic and colleague Dr. De Zhang Dai, of Case Western Reserve University and National Donghua University, are investigating how large hollow asteroids can grow without collapsing, and whether a primordial black hole is The probability of passing was calculated. Earth.

“Because of such long odds, we have focused on hard traces that have existed for thousands, millions, or even billions of years,” Dr. Dai said. .

“If the object has a liquid central core, a trapped primordial black hole could absorb the liquid core, whose density is higher than that of the outer solid layer,” Professor Stojković added.

“In that case, if the object was hit by an asteroid, the primordial black hole could escape from the object, leaving only a hollow shell.”

But would such a shell be strong enough to support itself, or would it simply collapse under its own tension?

Comparing the strength of natural materials such as granite and iron to their surface tension and surface density, the researchers found that such hollow objects could be less than one-tenth the radius of the Earth, making them smaller than normal We calculated that it was more likely to be an asteroid than a planet. .

“If it gets any bigger, it will collapse,” Professor Stojković said.

“These hollow objects could potentially be detected with telescopes. The mass, and therefore the density, can be determined by studying the objects' trajectories.”

“If an object's density is too low for its size, that's a good sign that it's hollow.”

For objects without a liquid core, the primordial black hole could simply pass through, leaving a straight microtunnel behind.

For example, a primordial black hole with mass 10twenty two grams, leaving a tunnel 0.1 microns thick.

Large slabs of metal or other materials could serve as effective black hole detectors by monitoring the sudden appearance of these tunnels, but very old materials from buildings that are hundreds of years old Searching for existing tunnels has a higher probability. From the oldest to rocks that are billions of years old.

Still, even assuming that dark matter is indeed composed of primordial black holes, they calculated that the probability that a primordial black hole would pass through a billion-year-old rock is 0.000001.

“You have to compare costs and benefits. Does it cost a lot of money to do this? No, it doesn't,” Professor Stojković said.

“So, to say the least, it's unlikely that a primordial black hole will pass through you during your lifetime. Even if you did, you probably wouldn't notice.”

“Unlike rocks, human tissue has a small amount of tension, so the primordial black hole won't tear it apart.”

“And while the kinetic energy of a primordial black hole may be huge, it is moving so fast that it cannot release much of that energy during a collision.”

“If a projectile is moving through a medium faster than the speed of sound, the molecular structure of the medium has no time to react.”

“If you throw a rock through a window, it will probably break. If you shoot a window with a gun, it will probably just leave a hole.”

team's paper Published in a magazine physics of the dark universe.

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De Chan Dai and Dejan Stojković. 2024. We're looking for planets, asteroids, and tiny primordial black holes on Earth. physics of the dark universe 46: 101662;doi: 10.1016/j.dark.2024.101662

Source: www.sci.news

Astronomers conduct simulations of undetected asteroids within our galaxy

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Astronomers discover large planets around other stars more often than small planets.whether to measure The gravitational pull of an exoplanet on its host starobserve How much starlight do exoplanets block?or Take a photo of the exoplanet itselfObservation methods for exoplanets are biased toward planets with masses twice the mass of Earth, or 12 septillion kilograms or more. But astronomers know that small planets exist. It's just harder to find because the smaller the planet, the more accurate equipment is needed.

Astronomers call planets smaller than Earth: sub-earth or asteroid. Current telescopes are bad at finding these tiny planets, so astronomers rely on simulations to determine how they behave. A team of astronomers studied the conditions of a hypothetical planetary system containing only asteroids. They argued that understanding where asteroids are likely to appear in large numbers will allow scientists to better understand how common these types of planets are.

To obtain a representative sample of the right conditions for planetary systems to form, astronomers simulation codeGenerate models of exoplanets similar to actual observations. Using this code, the team ran 33 sets of 1,000 simulations, each set with different starting parameters. Most stars in the Milky Way are in that size range, so they simulated a system containing stars ranging from 1/2 to 5 times the mass of the Sun. They ran all but the last two sets of simulations over a billion years of simulation time.

The first set was their point of comparison. This demonstrated that the code would produce a system containing asteroids given the same conditions as a solar system in which planets smaller than Earth are known to exist. In the next set of eight, they varied the mass of the host star, the spread of mass within the disk of matter's starting point, and the ratio of gas to dust in the system. The astronomers then ran four sets of experiments varying the period during which the asteroid could accumulate new material, ranging from 320,000 to 32 million years. The researchers ran 16 more sets, varying the amount of dust the system needed to start with, from exactly the same mass of Earth to 10,000 times the mass of Earth.

The astronomers' last four sets of simulations varied depending on the host star's mass, which ranges from 1.5 to 5 times the mass of the Sun. They ran their two largest sets on shorter timescales than the rest because large stars burn out their fuel faster and have shorter lifetimes than smaller stars. At the end of a star's life, it expands, sometimes quite dramatically. Scientists used these sets to find scenarios in which the star swallows the asteroid as it expands, and scenarios in which the star survives.

The researchers noted that computing power limits the scope of the simulation, as certain systems cannot perform calculations on more than 1,000 objects at once. Also, ice and rock were not allowed to accumulate at the edges of the system, as they do in real star systems. They said these factors limit the accuracy of models of planet formation processes and long-term system dynamics, respectively.

Overall, the research team found that asteroids should be extremely abundant in the universe. They found that under the parameters they studied, systems consisting of only planets between 1 and 110 million times the mass of Earth could “easily form.” They suggested that estimates of how often planets form around stars may significantly underestimate the actual frequency of planets.

Astronomers have found that the most important factor determining how large an asteroid becomes is the amount of dust it can initially form. But they also found that systems containing only small planets stop forming when the initial available dust exceeds 100 times the mass of Earth. Their final conclusions dealt with the outermost asteroids of certain systems, which are more than 10 times the distance from Earth to the Sun. They found that although these planets rarely grow larger than small moons, they can survive the star's inevitable expansion and persist for billions of years after the star's expansion.


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Study suggests that the majority of Earth’s meteorites come from the breakup events of only a few asteroids

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A new study shows that about 70% of meteorites originate from at least three recent breakups of giant asteroids.

This is the artist's impression of the asteroid as it breaks apart. Credit: NASA/JPL-California Institute of Technology.

A type of meteorite, commonly called a chondrite, accounts for about 80% of all meteorites that hit Earth, including those that were involved in the violent impact period about 466 million years ago that is thought to have started the Ice Age. Included.

Previous studies have demonstrated that approximately 70% of meteorites on Earth have compositions known as H and L chondrites.

Argon-argon dating of L-chondrite meteorites on Earth suggests that these samples may have originated from the catastrophic destruction of a single asteroid that experienced a supersonic impact approximately 470 million years ago. It turned out to be high.

in new researchESO and MIT researcher Dr. Michael Marcet and colleagues have compiled spectroscopic data from asteroids in the main belt between Mars and Jupiter.

They found that a group of asteroids known as the Massalia family is very similar in composition to L-chondrite meteorites on Earth.

Through computer modeling, they propose that an impact event about 450 million years ago destroyed an L-chondrite asteroid, forming the Massalia family and providing debris that fueled the influx of meteorites.

in second studyCharles University researcher Miroslav Broz and his colleagues found that the current influx of H and L chondrite meteorites was likely caused by three recent breakups.

These events occurred about 5.8, 7.6 and 40 million years ago and involved the destruction of asteroids over 30 km (18.6 miles) in diameter.

More specifically, they suggest that the impact formation of the relatively young Karin and Coronis asteroid families and a second impact event (about 40 million years ago) in the older Massalia asteroids are currently falling to Earth. I guessed that explained most of the meteorites.

in Third, follow-upDr. Brož and his co-authors extended their approach to the entire meteorite family, revealing the major origins of carbonaceous chondrites and achondrites, in addition to those from the Moon, Mars, and Vesta.

“Our discovery provides insight into the mystery of where the most common meteorites that have ever hit Earth came from and how those impacts shaped Earth's history.” ,” the researchers said.

The results are published in three papers. journal nature and journal astronomy and astrophysics.

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M. Marcet others. 2024. Massalia asteroid family as the origin of ordinary L chondrites. nature 634, 561-565; doi: 10.1038/s41586-024-08007-6

M. Broz others. 2024. Young asteroids as the main source of meteorites. nature 634, 566-571; doi: 10.1038/s41586-024-08006-7

M. Broz others. 2024. Source region of carbonaceous meteorites and near-Earth objects. A&A 689, A183; doi: 10.1051/0004-6361/202450532

Source: www.sci.news

Astronomers Discover Fewer Potentially Hazardous Asteroids Near Earth than Initially Predicted

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astronomer using Zwicky Temporary Facility (ZTF) investigated. Taurus resonance groupa large interplanetary system containing Comet 2P/Encke, several meteor showers, and possibly numerous near-Earth asteroids.

This image taken by NASA's Spitzer Space Telescope shows comet 2P/Encke running along a pebble trail of its debris. Image credit: NASA / JPL-Caltech / University of Minnesota.

“We can take advantage of the unique opportunity that this asteroid swarm has to approach Earth to more efficiently search for celestial objects that may pose a threat to Earth,” said Dr. Kuanji Ye, an astronomer at the University of Maryland. ” he said.

“Our results suggest that the risk of impact from large asteroids in the Taurus group is much lower than we thought, which is good news for planetary defense.”

Prior to this study, astronomers had predicted that the Taurus resonance complex contained a significant number of large kilometer-sized space rocks, probably left behind by large objects up to 100 kilometers (62 miles) wide. I was guessing.

If a large object were to hit Earth, like the Chelyabinsk asteroid in 2013, it could cause regional damage.

Even larger objects can cause extinction-level events, like the asteroid that wiped out the dinosaurs more than 66 million years ago.

“Fortunately, we found that there are likely only a small number of asteroids in this large size class, perhaps only nine to 14, in this population,” Dr. Ye said.

“Judging by our findings, the parent object that first spawned the swarm was probably closer to 10 km (6.2 miles) in diameter, rather than a giant 100 km diameter object.”

“We still need to be cautious about asteroid impacts, but knowing this result will probably help us sleep better.”

The Taurus swarm holds important clues about planetary evolution, especially because of its association with Comet Encke.

This comet has the shortest orbital period of any known comet, at just 3.3 years.

It is also unusually large and dusty for a short-period comet that orbits the sun within 200 years.

Considering all available evidence, scientists believe that Encke has experienced significant fragmentation in the past and may continue to do so in the future.

“Studying the Taurus swarm helps us understand how small objects like comets and asteroids form and break up over time,” said Dr. Ye.

“Our research has implications not only for asteroid detection and planetary defense, but also for our broader understanding of the solar system's celestial bodies.”

The researchers presented their findings. findings this week's DPS56Annual Meeting of the Planetary Science Division of the American Astronomical Society.

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Yosenshi others. 2024. In search of potentially dangerous asteroids in the Taurus resonance group. DPS56

Source: www.sci.news

Astronauts Could Potentially Consume Asteroids in the Future

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Samples from asteroid Ryugu

JAXA

Future astronauts may be able to eat a nutritionally complete meal made from bacteria grown on crushed asteroids, creating a type of milkshake or yogurt.

Astronauts on the International Space Station are experimenting with growing salad leaves, but most of the food consumed in space comes from Earth. This will not be possible for more distant and longer duration space missions. joshua pierce and his colleagues at Western University in Ontario, Canada, decided to study the use of bacteria to convert carbon-containing compounds from asteroids into edible food.

Although they have not yet performed this process using real asteroids, Pearce and his team performed a similar experiment using bacteria that breaks down plastic from leftover military ration packets. To do this, they heated the plastic in the absence of oxygen, a process called pyrolysis, and fed this to a mixture of carbon-eating bacteria.

“If you look at the pyrolysis products that bacteria are known to eat and the materials found in asteroids, there's actually a pretty reasonable match,” Pearce said. “So I think this really works.”

The bacterial aggregates end up being “something like a caramel milkshake,” Pearce said, and the team is also experimenting with drying the material to make something like yogurt or powder.

Although it may not be very appetizing, Pearce says this bacteria is highly suited for human needs. “We did a nutritional analysis and found it to be a nearly perfect food,” he says. “We found that the bacterial consortium we were using was more or less allocating a third each to protein, carbohydrates, and fat.”

If this idea is correct, a 500-meter-wide asteroid similar to Bennu, which NASA visited in 2020, could feed between 600 and 17,000 astronauts for a year, Pierce said. say. The exact amount depends on how efficiently the bacteria can digest the asteroid's carbon compounds.

A fully operational asteroid food project would require an “industrial-sized supermachine” in space, but researchers will begin testing the idea on a small scale next year, starting with coal. He says he wants to move on to meteorites next. They are currently working on the proposal. “It's very expensive, so we have to destroy it.” [the meteorites]So when we made these proposals, the stone collectors were not happy,” Pearce says.

“There's definitely potential there, but it's still a very futuristic and exploratory idea,” he says. Annemiek Wargen At the Vrije Universiteit Amsterdam. “It's good to think about these things, but in terms of technology, there's still quite a bit of development to be done before we can use these methods.”

The success of this process depends on how much of the carbon compounds in the asteroid are suitable food for bacteria, Wagen said. Based on the composition of meteorites on Earth, it's likely somewhere in the middle of the range the researchers calculated, she says.

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Source: www.newscientist.com

454 new asteroids discovered in the main asteroid belt by astronomers

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632 main-belt asteroids (178 known objects and 454 unknown objects) have been identified in archival images from the NASA/ESA Hubble Space Telescope. Citizen scientists from around the world contributed to the discovery of this asteroid. Professional astronomers identified the asteroid using a combination of volunteer efforts and machine learning algorithms.

This Hubble image of barred spiral galaxy UGC 12158 looks like someone took it with a white marking pen. In reality, this is a combination of long exposures of a foreground asteroid moving within Hubble's field of view, adding light bombardment to observations of the galaxy. The galaxy was photographed several times. The dashed pattern is proof of this. Due to parallax, the asteroid appears as a curved trajectory. Hubble is not stationary, but orbits around the Earth, giving the illusion of a faint asteroid swimming along a curved trajectory. This unknown asteroid is located inside the solar system's asteroid belt, so it is 10 trillion times closer to Hubble than the background galaxy. Image credits: NASA / ESA / Hubble / Pablo García Martín, UAM / Joseph DePasquale, STScI / Alex Filippenko, University of California, Berkeley.

More than 4 billion years ago, the eight major planets around the sun formed by sweeping up debris from the vast disk of dust and gas surrounding the sun.

This is common in the birth process of planets, and the NASA/ESA Hubble Space Telescope has for the first time optically observed a similar disk surrounding a newborn star, providing a glimpse into the solar system's formative years.

Four billion years later, debris still litters the planet's construction yards.

Most of this ancient space debris, or asteroids, lies between the orbits of Mars and Jupiter within the main asteroid belt.

“We are starting to learn more about the presence of a small number of main-belt asteroids,” said Dr. Pablo García Martín, an astronomer at the Autonomous University of Madrid.

“We were surprised to see so many candidate objects.”

“We've had some hints that this population exists, but we're now confirming it with a random asteroid population sample obtained using the entire Hubble archive.”

“This is important for gaining insight into models of the evolution of the solar system.”

Since Hubble orbits around the Earth at high speed, Hubble exposure allows us to follow its trail and capture a wandering asteroid.

When viewed from a telescope on Earth, the asteroid leaves streaks across the photo.

The asteroid appears as an unmistakable curved trajectory in the photo, making the Hubble exposure a “photobomb.”

Hubble observes the asteroid from different perspectives as it moves around Earth, but the asteroid also moves along its own orbit.

By knowing Hubble's position during observations and measuring the curvature of its stripes, scientists can determine the distance to the asteroid and estimate the shape of its orbit.

Most of the asteroids involved are in the main belt between the orbits of Mars and Jupiter.

Their brightness is measured by Hubble's sensitive camera. Then, by comparing its brightness and distance, we can estimate its size.

The faintest asteroid found in the survey is approximately 40 million times less bright than the faintest star visible to the human eye.

“Because the asteroid's position changes over time, you can't find the asteroid's location just by entering the coordinates, because the asteroid may not be there at a different time,” Melin said.

“As astronomers, we don't have time to study images of every asteroid.”

“So we came up with the idea of ​​collaborating with more than 10,000 citizen science volunteers to browse the massive Hubble archive.”

of result appear in the diary astronomy and astrophysics.

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Pablo Garcia-Martin other. 2024. Hubble Asteroid Hunter III. Physical properties of newly discovered asteroids. A&A 683, A122; doi: 10.1051/0004-6361/202346771

Source: www.sci.news

Fifteen new active asteroids discovered in Citizen Science Project

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Active asteroids behave dynamically like asteroids, but exhibit coma like comets. These objects are poorly understood, and fewer than 60 have been identified to date.

Asteroids discovered to be active as a result of the Active Asteroid Project: (af) Candidates for active asteroids and main-belt comets. (g) Active centaur. (hl) Active sub-Hilda asteroid. (mt) Jupiter-based comets.Image credit: Chandler other10.3847/1538-3881/ad1de2.

Active asteroids appear to have comet-like tails, but they follow orbits primarily within the asteroid belt.

Near-Earth asteroid (4015) Wilson-Harrington, the first active asteroid with a prominent tail, was discovered in 1949.

Fewer than 60 asteroids have been confirmed to be active in the past 70 years, a small fraction of the 1.3 million known asteroids, and the majority of discoveries have occurred in just the past 25 years.

citizen science project active asteroida NASA partner, is designed to find these rare objects.

Launched on August 31, 2021, the project is hosted on the Zooniverse online platform and has over 8,300 volunteers.

To find new active asteroids, volunteers combed through 430,000 images taken by the satellite. dark energy camera (DECam) instrument located on the 4 m Blanco telescope at the Cerro Tororo Inter-American Observatory.

“For an amateur astronomer like me, this is a dream come true,” said Virgilio Gonano, a volunteer from Udine, Italy.

“Congratulations to all the staff and friends who checked out the images!”

The volunteers were able to identify previously unknown activity in 15 asteroids and one Centaurus that were thought to be asteroids (i.e. inactive).

“I'm a member of the Active Asteroids team from the first batch of data,” said Tiffany Shaw Diaz, a volunteer from Dayton, Ohio, USA.

“And it is no exaggeration to say that this project has become an important part of my life.”

“I look forward to classifying subjects every day, as time and health permit. I am deeply honored to work with such esteemed scientists on a regular basis.”

of the project new paper Published in astronomy magazine.

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colin orion chandler other. 2024. Active Asteroid Citizen Science Program: Overview and First Results. A.J. 167, 156; doi: 10.3847/1538-3881/ad1de2

Source: www.sci.news

Five asteroids narrowly miss Earth today, including one with the potential to cause widespread destruction

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Today, not one, but five asteroids are hurtling past Earth, all at their closest approach.

The largest one was discovered just a few weeks ago. Potentially Dangerous 2024 BR4. Measuring between 140 and 300 meters in length, it is a sizable chunk of space rock. At its highest estimate, it would be about the size of an oil tanker, six Olympic-sized swimming pools, or as tall as New York City's Chrysler Building.

And just like the box of chocolates you might stuff your cheeks with, we have a few more surprises in store for you on the day. Dr. Darren Baskillan astronomer at the University of Sussex, said:

“On Wednesday, February 14, 2024, a total of five asteroids will pass Earth, all within 5 million kilometers.”

It may seem like a long way, but from an astronomical perspective, it's just a stone's throw away.

“The closest of these five is asteroid 2024 CU1, which is scheduled to pass about 52 percent further away than the Moon and is about 20 meters in diameter.”

In 2024, CU1 will be closest at 1:31 PM GMT (+/- 1 minute). However, it is only 20 meters in diameter, much smaller than the much talked about “city killer” called 2024 BR4.

How close will asteroid 2024 BR4 get?

Asteroid 2024 BR4, one of a group of asteroids that will fly past Earth today, will make its closest approach at a distance of 4.6 million km (2.86 million miles). In terms of AU, this is approximately 0.03 AU, well within the criteria for designation as a potentially hazardous object (see Meaning of a “Potentially Hazardous” Asteroid below).

(To convert kilometers per mile to AU, divide the distance in kilometers per mile by the distance in 1 AU of the same unit.)

Closest approach is expected to occur at 11:03 GMT today (±1 minute).

Will asteroid 2024 BR4 collide with Earth?

The Valentine's Day asteroid is hurtling through space at about 44,880 kilometers per hour (27,887 miles per hour), only slightly faster than the average speed recorded by Galileo during his six-year mission to Jupiter, but we… No need to worry. About influencing our heavenly oasis.

It passes us safely and poses no immediate threat to Earth.

“Asteroid 2024 BR4 will pass close to Earth 12 times further away than the Moon,” Baskill explains.

What do we know about Asteroid 2024 BR4?

Unfortunately, there are very few. In general, the larger the object, the brighter it is (the brighter the object, the lower the magnitude). NASA assigned asteroid 2024 BR4 a magnitude of 21.457.. It's not very bright.

However, we also need to know the object's albedo (surface reflectance), which is currently unknown. Current best estimates place the asteroid's size between 140 and 300 meters in diameter. But we know its trajectory with relative certainty. And today's visit will bring us the closest in 120 years to realizing BR4 in 2024.

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Polycyclic Aromatic Hydrocarbons in Asteroids Found to Predate the Solar System, New Study Shows

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Astronomical observations have shown that polycyclic aromatic hydrocarbons (PAHs) are abundant and widespread in the interstellar medium. A PAH molecule consists of several adjacent aromatic rings terminated with hydrogen. In the new study, scientists conducted laboratory isotope analysis of PAHs in samples of the asteroid Ryugu and meteorite Murchison collected by JAXA’s Hayabusa2 spacecraft. They argue that at least some of the Ryugu PAHs formed in cold interstellar clouds and therefore must be older than our solar system.

This image of asteroid Ryugu was taken on June 26, 2018 by the Telescopic Optical Navigation Camera (ONC-T) aboard JAXA’s Hayabusa 2 spacecraft from a distance of 13.7 miles (22 km).Image provided by: JAXA / University of Tokyo / Kochi University / Rikkyo University / Nagoya University / Chiba Institute of Technology / Meiji University / University of Aizu / AIST

PAHs contain about 20% of the carbon in the interstellar medium.

These can be produced in the circumstellar environment (temperatures above 1000 K), in cold interstellar clouds (temperatures around 10 K), or by the processing of carbon-rich dust particles.

“PAHs are organic compounds composed of carbon and hydrogen that are common on Earth but also occur in celestial bodies such as asteroids and meteorites,” said study co-author and director of the Western Australian Center for Organic Isotope Geochemistry. said researcher Professor Kriti Grice. Curtin University.

“We conducted controlled combustion experiments on plants in Australia and found that PAHs found in debris from the asteroid Ryugu returned to Earth by a Japanese spacecraft in 2020, and comparable to the Murchison meteorite that landed in Australia in 1969. I compared them physically.”

“We analyzed the bonds between light and heavy carbon isotopes in PAHs to reveal the temperatures at which they form.”

“Selected PAHs from Ryugu and Murchison were found to have different characteristics, with smaller ones probably forming in cold outer space and larger ones probably forming in warmer regions such as near stars or inside celestial bodies. It is thought to have been formed in the environment.”

A model of the molecular structure of ribose and an image of the Murchison meteorite. Image credit: Yoshihiro Furukawa.

“Understanding the isotopic composition of PAHs can help elucidate the conditions and environments in which these molecules were formed, providing insight into the history and chemistry of astronomical objects such as asteroids and meteorites,” says the study. said Dr. Alex Holman, co-author and fellow Westerner. Australian Center for Organic and Isotopic Geochemistry at Curtin University.

“This research gives us valuable insight into how organic compounds form extraterrestrially and where in the universe they come from.”

“Through the use of high-tech methods and creative experiments, we show that select PAHs on asteroids can form even in cold space.”

of result Published in this week’s magazine science.

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Sarah S. Zeichner other. 2023. Polycyclic aromatic hydrocarbons in Ryugu samples formed in the interstellar medium. science 382 (6677): 1411-1416; doi: 10.1126/science.adg6304

Source: www.sci.news