Scientists believe they have recovered the first known interstellar meteorite

A scientific expedition in the Pacific off the coast of Papua New Guinea has found what it thinks are spherules from the first known interstellar meteorite that hit the Earth on January 8, 2014 and dubbed IM1. From their preprint paper [pdf]:

On 8 January 2014 US government satellite sensors detected three atmospheric detonations in rapid succession about 84 km north of Manus Island, outside the territorial waters of Papua New Guinea (20 km). Analysis of the trajectory suggested an interstellar origin of the causative object CNEOS 2014-01-08: an arrival velocity relative to Earth in excess of ∼ 45 km s−1, and a vector tracked back to outside the plane of the ecliptic. The object’s speed relative to the Local Standard of Rest of the Milky-Way galaxy, ∼ 60 km s−1, was higher than 95% of the stars in the Sun’s vicinity.

In 2022 the US Space Command issued a formal letter to NASA certifying a 99.999% likelihood that the object was interstellar in origin.

Using a “magnetic sled” that they dragged across the seafloor, the scientists collected about 700 spherules thought to come from the meteorite, of which 57 have been analyzed and found to have properties that confirm their interstellar origin. As they note in their paper, “The spherules with enrichment of beryllium (Be), lanthanum (La) and uranium (U), labeled “BeLaU”, appear to have an exotic composition different from other solar system materials.”

The “BeLaU” elemental abundance pattern does not match terrestrial alloys, fallout from nuclear explosions, magma ocean abundances of Earth, its Moon or Mars or other natural meteorites in the solar system. This supports the interstellar origin of IM1 independently of the measurement of its high speed, as reported in the CNEOS catalog and confirmed by the US Space Command.

Based on the sparse data, the scientists speculate that these spherules could have come from the crust of an exoplanet, the core collapse of a supernova, the merger of two neutron stars, and even possibly “an extraterrestrial technological origin.” They have no idea, but all these are among the possibilities.

New software detects its first potentially dangerous asteroid

New software designed to detect asteroids, developed for use with the Rubin Observatory presently being built in Chile, has successfully discovered its first potentially hazardous asteroid (PHA) using data from another smaller operational ground-based telescope.

The discovered asteroid is 600 feet long, large enough to pose a real threat should it ever hit the Earth. Fortunately, the data says that though its orbit can take it as close as 140,000 miles there is no impact likely in the foreseeable future.

When the Rubin telescope begins its planned ten year survey of the entire night sky in 2025, this software is expected to almost triple the number of known potentially-hazardous-asteroids, from 2,350 to almost 6,000.

Funded primarily by the U.S. National Science Foundation and the U.S. Department of Energy, Rubin’s observations will dramatically increase the discovery rate of PHAs. Rubin will scan the sky unprecedentedly quickly with its 8.4-meter mirror and massive 3,200-megapixel camera, visiting spots on the sky twice per night rather than the four times needed by present telescopes. But with this novel observing “cadence,” researchers need a new type of discovery algorithm to reliably spot space rocks.

Thus, the development of this new software.

OSIRIS-REx completes last major mid-course correction before sending its sample capsule back to Earth

OSIRIS-REx yesterday completed a 63 second engine burn, successfully aiming the spacecraft so that its September 24th drop off of its sample capsule will hit the Earth as planned.

Preliminary tracking data indicates OSIRIS-REx changed its velocity, which includes speed and direction, by 1.3 miles, or 2 kilometers, per hour. It’s a tiny but critical shift; without course adjustments like this one the spacecraft would not get close enough to Earth on Sept. 24 to drop off its sample of asteroid Bennu. The spacecraft is currently 24 million miles, or 38.6 million kilometers, from Earth, traveling at about 22,000 miles, or about 35,000 kilometers, per hour.

In the two weeks prior to that drop-off the spacecraft will do two more short burns to refine its aim so that the sample capsule will land precisely as planned on the Defense Department’s Utah Test and Training Range near Salt Lake City.

Hubble image shows several dozen boulders flung from Dimorphos

Boulders drifting from Dimorphos
Click for original image.

Using the Hubble Space Telescope, astronomers have photographed several dozen boulders that were flung off of the asteroid Dimorphos following the impact by the space probe DART. The picture to the right, reduced and brightened to more clearly show those boulders, was taken on December 19, 2022, four months after DART’s impact.

These are among the faintest objects Hubble has ever photographed inside the Solar System. The ejected boulders range in size from 1 meter to 6.7 meters across, based on Hubble photometry. They are drifting away from the asteroid at around a kilometre per hour.

The blue streak is the dust tail that has streamed off of Dimorphos since the impact, pushed away from the sun by the solar wind.

The possibility of more than one exoplanet sharing the same orbit

PDS 70, as seen by ALMA
The Trojan debris clouds around PDS 70, as seen by ALMA

The uncertainty of science: Astronomers have detected evidence that suggests the possibility of more than one exoplanet sharing the same orbit around PDS 70, a star 400 light years away.

This young star is known to host two giant, Jupiter-like planets, PDS 70b and PDS 70c. By analysing archival ALMA observations of this system, the team spotted a cloud of debris at the location in PDS 70b’s orbit where Trojans are expected to exist.

Trojans occupy the so-called Lagrangian zones, two extended regions in a planet’s orbit where the combined gravitational pull of the star and the planet can trap material. Studying these two regions of PDS 70b’s orbit, astronomers detected a faint signal from one of them, indicating that a cloud of debris with a mass up to roughly two times that of our Moon might reside there.

The press release — as well as most news reports — touts the possibility that they have found a second planet in this orbit. They have not, and are likely not going to. As noted above, the data indicates the presence of “a cloud of debris”, which is most likely a clustering of Trojan asteroids, just as the more than 12,000 asteroids we see in the two Trojan points in Jupiter’s orbit.

Nonetheless, this is the first detection of what appears to be a Trojan clustering in the accretion disk of a young star.

NASA gives up on finding a new asteroid target for Janus

Without funding for its own launch vehicle, and unable to find a new asteroid target that can be reached by any future planned NASA launch, NASA has decided to shelf the Janus asteroid mission, putting the spacecraft into storage.

Designed to send twin small satellite spacecraft to study two separate binary asteroid systems, Janus was originally a ride-along on the Psyche mission’s scheduled 2022 launch. Psyche’s new October 2023 launch period, however, cannot deliver the two spacecraft to the mission’s original targets, and Janus was subsequently removed from the manifest.

The spacecraft will remain in storage, and might be revived at some point in the future, should another mission’s launch allow it to reach some other asteroid.

More evidence found suggesting supernovae occurred near the solar system during its formation

Scientists have now detected more evidence that suggests a supernovae occurred very close to our solar system during its early period of formation.

Astronomers have for decades found such evidence inside meteorites. Small spherical inclusions called chondrules are thought by some to have formed when the heat of a nearby supernova caused melting. The new study finds more evidence in isotopes also found in primitive meteorites dubbed short-lived radionuclides (SLRs).

While SLRs probably existed in the part of the filament where the Sun and Solar System formed, the meteorite samples contained too much of a particular aluminum isotope for the interstellar medium to have been the Solar System’s only SLR source. Cosmic rays, which can convert stable isotopes to radioactive ones, had a better chance of explaining the number of isotopes found in the meteorites. However, it would have taken too long for this process to produce the levels of SLRs found in the early Solar System.

It is most likely that such high SLR levels could have come from either very intense stellar winds, which would have occurred during massive star formation, or from what was left after one of the massive stars went supernova.

You can read the published paper here.

If true, this data adds weight to the possibility that our solar system is somewhat unique, which in turn suggests finding just another like it — with life — might be difficult.

China conducts parachute tests for returning asteroid sample to Earth

China has successfully conducted tests of the parachute design that will be used by the sample return capsule of its Tianwen-2 mission to grab samples from the near Earth asteroid dubbed 469219 Kamoʻoalewa.

The mission will launch on a Long March 3B rocket in 2025, and rendezvous with the asteroid in 2025. After getting its samples and releasing the sample return capsule, the plan is to then send Tianwen-2 to Comet 311P/PANSTARRS, arriving in the 2030s.

The probe uses fanlike solar panels, apparently copied from those used by NASA’s Lucy asteroid probe. China also has copied the touch-and-go sample grab methods used by OSIRIS-REx and Hayabusa-2, but it will also try its own original idea, to anchor to the asteroid and use drills in the probe’s landing legs.

NASA: Psyche asteroid mission now targeting October ’23 launch

A report [pdf] from NASA on the steps taken by JPL to get the Psyche asteroid mission back on track after it failed to meet its launch date last fall says those steps are working, and the spacecraft should now succeed in meeting its new October ’23 launch date.

Both the report and today’s press release are filled with vague PR blather interspersed with complementing JPL for addressing the issues, including hiring about a dozen more people to get the main software issue that had prevented last year’s launch solved. I noticed one point however that was not mentioned clearly in the press release nor had been made clear in the earlier investigation report that today’s newly released report labels as “COVID-19 Related” issues.

The return to majority in-person work has made a tremendous difference in restoring visibility and informal communications across the project. Drop-in meetings, social coffee hours, off-site intensives, and individuals “walking the floor” have improved team interaction, problem-solving, efficiency, and trust. The team is also making judicious use of remote and hybrid access options as appropriate to ensure flexibility while not compromising their collaboration.

In other words, the panic over Wuhan had so restricted in-person contact at JPL that it had hampered the project’s development. Based on the vague language used to describe almost everything else mentioned in this new report, it appears that this issue more than anything else contributed the launch delay. Not surprisingly, no one at NASA, JPL, Caltech, or in the government wishes to make this admission bluntly. It would illustrate once again the foolishness of the lockdown policies imposed during the panic by the government and academia.

Astronomers think they have completed the census of Near Earth asteroids

Astronomers in a new paper [pdf] have concluded that the census of Near Earth asteroids is largely now complete, and have begun focusing their effort on narrowing down the list of potentially dangerous asteroids in that census. From the press release:

Researchers from CU Boulder and NASA have completed a census of hundreds of large asteroids orbiting near Earth—gauging which ones could come precariously close to our planet over the next thousand years. The researchers identified at least 20 asteroids that scientists may want to study more to make certain they pose no threat to life on Earth in the next millennium.

To be clear, the researchers say the odds of any of these rocky bodies striking the planet are extremely low, and are next to zero for the coming century. But because the fallout from such an impact would be catastrophic, it’s important to be sure, said Oscar Fuentes-Muñoz, lead author of the study. “We don’t want to alarm people, because the results are not alarming,” said Fuentes-Muñoz, a doctoral student in the Ann and H.J. Smead Department of Aerospace Engineering Sciences. “But there are a lot of uncertainties in predicting so far into the future.”

To sum up, none of those 20 asteroids has any chance of hitting the Earth in the next few hundred years. Beyond that the uncertainties make it difficult to predict. Reducing those uncertainities is now the focus of their work.

Lucy makes course correction in preparation for 1st asteroid fly-by

Lucy's route through the solar system
Lucy’s route through the solar system

The asteroid probe Lucy on May 9, 2023 fired its engines to successfully make a minor course correction in preparation for a fly by of the asteroid Dinkinesh, located in the main asteroid belt between Mars and Jupiter.

Even though the spacecraft is currently travelling at approximately 43,000 mph (19.4 km/s), this small nudge is enough to move the spacecraft nearly 40,000 miles (65,000 km) closer to the asteroid during the planned encounter on Nov. 1, 2023. The spacecraft will fly a mere 265 miles (425 km) from the small, half-mile- (sub-km)-sized asteroid, while travelling at a relative speed of 10,000 mph (4.5 km/s).

Dinkinesh, the white dot inside the main asteroid belt in the lower left of the map to the right, is the first of eight asteroids Lucy will fly past.

UAE asteroid mission will rendezvous with seven asteroids and will include lander

Though the mission was first announced in 2021, the UAE only recently revealed at a science conference the mission’s specific targets and plan.

From the conference poster [pdf]:

The mission will launch in 2028 and visit 7 main belt asteroids, including 6 high-speed flyby encounters en route to a rendezvous with the asteroid 269 Justitia. The mission is enabled by solar electric propulsion and gravity assist flybys of Venus, Earth, and Mars, bringing the total number of mission encounters to 10. The trajectory design presented will include the overall timeline of the mission, launch targets, launch period, overall duration of the encounters, design of the encounters, and trajectory modeling. Mission design analyses include designing the Deep space maneuvers (DSMs) prior to the rendezvous with Justitia and design Justitia’s orbits and maneuvers to accomplish the lander deployment.

As with the UAE’s Al-Amal Mars Orbiter, the country is relying on an American university, the University of Colorado, as well as the commercial company, Advanced Space, to design, build, and operate the spacecraft. In this sense the UAE is paying these American entities to fly the mission while requiring them to train its own engineers and scientists.

Meteorite crashes through roof of NJ home

On May 8, 2023 a family in New Jersey returned home to discover a 4×6 inch meteorite on the floor of one bedroom, having crashed through the roof of their home.

Suzy Kop, a resident of the home, told CBS Philadelphia that meteorite landed in her father’s bedroom, but no one was home. “I thank God that my father was not here, no one was here, we weren’t hurt or anything,” Kop told the station.

She found the object, she said, amid debris in the room after it came through the ceiling. At first, she said she believed it had been thrown. “I did touch the thing, because I thought it was a random rock, I don’t know, and it was warm,” she told CBS Philadelphia.

Though not unprecedented, there are only a few recorded examples of meteorites landing in populated areas like this.

The inexplicable tail of the asteroid Phaethon is from sodium, not dust

For years astronomers have puzzled over the strange behavior of the asteroid Phaethon, which though rocky would still produce a tail like a comet whenever its orbit took it close to the Sun.

New research by astronomers using several space telescopes designed to study the Sun has determined that this tail is made of sodium, not dust as previously believed, which also suggests that many of the other “comets” these solar telescopes have detected close to the Sun might instead be asteroids like Phaeton.

Hoping to find out what the tail is really made of, Zhang looked for it again during Phaethon’s latest perihelion in 2022. He used the Solar and Heliospheric Observatory (SOHO) spacecraft — a joint mission between NASA and the European Space Agency (ESA) – which has color filters that can detect sodium and dust. Zhang’s team also searched archival images from STEREO and SOHO, finding the tail during 18 of Phaethon’s close solar approaches between 1997 and 2022.

In SOHO’s observations, the asteroid’s tail appeared bright in the filter that detects sodium, but it did not appear in the filter that detects dust. In addition, the shape of the tail and the way it brightened as Phaethon passed the Sun matched exactly what scientists would expect if it were made of sodium, but not if it were made of dust.

Knowing these new facts, it might make it possible to map the asteroids that orbit very close to the Sun but are hard to detect optically using standard telescopes because of the Sun’s brightness. Instead, astronomers might be able to map them using these solar telescopes.

Lucy snaps its first pictures of four of the Trojan asteroids it will visit

Lucy's first look at four Trojan asteroid targets
Click for original movie.

Lucy's route through the solar system
Lucy’s route through the solar system

Though still many millions of miles away and really nothing more than tiny dots moving across the field of stars, the science team for the asteroid probe Lucy have used the probe to take its first pictures of four of the eight Trojan asteroids it will visit during its travels through the solar system, as shown on the map to the right. The dots along its path show where Lucy will fly past asteroids, some of which are binaries.

The image at the top is a screen capture from a very short movie created from all of the images Lucy took of each asteroid. If you click on the picture you will see that movie. As I say, at this distance, more than 330 million miles away, the asteroids are nothing more than dots. The short films of each were obtained by pictures taken over periods from two to 10 hours long, depending on the asteroid.

These asteriods are all in the L4 Trojans, the first that Lucy will visit from ’27 to ’28.

Museum offers $25k for recovery of meteorite that landed in Maine April 8th

Meteorite landing track

Because a instrument operated by NOAA picked up radar data of an asteroid fall over Maine on April 8, 2023, it has been possible for NASA scientists to publish a track, shown to the right, of where any pieces of the meteorite might have landed.

As a result, the Maine Mineral and Gem Museum has offered a $25k reward to anyone who turns in the first piece weighing more than one kilogram.

The $25,000 reward is only for the first kilogram, but Pitt said that the museum will also buy other fireball pieces that are found. “Depending upon the type of meteorite this is, specimens could easily be worth their weight in gold,” he said.

The American Meteor Society received six witness reports of Saturday’s fireball, half of which were in northeast Maine. One of the witnesses described the meteorite as having a “long glowing tail (but no smoke).” Another said that it was “bright red” while the tail was “very white.”

The museum also emphasized that any meteorite hunters must get landowner permission before entering private land.

Scientists try to model what would happen if Ryugu hit Earth

Ryugu's northen hemisphere
Ryugu’s northen hemisphere. The arrow marks the spot Hayabusa-2
gathered samples

Scientists, using the data and rock samples gathered by the Japanese probe Hayabusa-2, have attempted to predict what what would happen if the rubble-pile asteroid Ryugu hit the Earth.

Without diversion intervention, Tanaka explained, if the Ryugu asteroid was heading to Earth and entered the planet’s atmosphere at an angle of 45 degrees and at a speed of around 38,000 miles per hour (17 kilometers per second), the rubble pile asteroid would break up at an altitude of around 25 to 21 miles (40 to 35 km) over the surface of the planet.

This would result in an “airburst” similar to that seen over Russia in February 2013 when the Chelyabinsk meteor erupted at an altitude of around 19 miles (30 kilometers) over Earth. The result of the Chelyabinsk blast was a bright flash of light and an atmospheric blast equivalent to the detonation of 400–500 kilotons of TNT. This is as much as 33 times the energy released by the atomic bomb that devastated Hiroshima at the end of the Second World War.

The Chelyabinsk meteor caused about 1,500 injuries, mostly from people injured by glass thrown out by breaking windows when it suddenly and unexpectedly exploded during re-entry. With Ryugu this would not be a surprise, so these injuries could be reduced, though not eliminated. The damage and injuries from pieces that survived the breakup and hit the ground remains unknown because scientists don’t know how much of the asteroid would survive the break up.

Ryugu of course poses no threat, because it is not on a collision course with Earth. Whether an asteroid like Ryugu could be diverted however remains unknown, since any such diversion must not cause the asteroid to break apart as well.

Psyche asteroid mission now scheduled for October 2023 launch

After a year delay because certain flight software was not ready on time for its first launch window in the fall of 2022, the science team for the Psyche asteroid mission are now aiming for an October 2023 launch.

The launch period will open Oct. 5 and close Oct. 25. The asteroid, which lies in the outer portion of the main asteroid belt between Mars and Jupiter, may be the remains of a core of a planetesimal, a building block of a rocky planet.

Due to the new launch date, Psyche has a new mission plan, which includes a flyby of Mars for a gravity assist and arrival at the asteroid in August 2029. The mission then will enter its 26-month science phase, collecting observations and data as the spacecraft orbits the asteroid at different altitudes.

Meanwhile, the two Janus probes that were to launch with Psyche last year remain in limbo, as this new Psyche launch date is useless to that mission’s plan to fly past a different asteroid.

Samples from Ryugu found to contain uracil, one of the four nucleobases in RNA

Japanese researchers analyzing the samples returned by Hayabusa-2 from the rubble-pile asteroid Ryugu have identified the molecule uracil, one of the four nucleobases that form the molecule RNA.

Hayabusa 2 collected 5.4 grams from two spots on Ryugu and delivered them to Earth on December 6, 2020. Early studies showed the samples contained many organic compounds. That led Oba’s group to analyze two 10-milligram samples using the same sensitive technique they had used earlier on meteorites. The technique can detect nucleic acid bases at levels down to parts per trillion in small samples.

Now, they report in Nature Communications that uracil is present at a level of parts per billion in both Ryugu samples. While this concentration is different than they’d previously found in meteorites, Oba says that might be because the parent bodies of the meteorites and of Ryugu underwent different levels of aqueous alteration and other processes. They also detected niacin (vitamin B3) as well as other organic molecules, but they didn’t find any other nucleobases.

RNA is formed from four nucleobases, uracil, adenine, cytosine, and guanine. To form DNA, the fundamental building block of life, uracil is replaced by thymine.

This data reinforces other data that suggests the formation of these essential molecules for life is relatively common and easy, at least in our solar system.

Dimorphus is dry, based on data obtained before and after DART hit it

Data collected by the ground-based Very Large Telescope (VLT) in Chile before and after the impact by the DART probe in September 2022 has revealed that the rubble-pile asteroid Dimorphos is very dry, with little or no water.

[The astronomers] observed the Didymos–Dimorphos system on 11 occasions, from just before the impact to about a month afterwards. MUSE [one of VLT’s instruments] is able to split the light from the double-asteroid into a spectrum, or rainbow, of colors, to look for emission at specific wavelengths that corresponds to specific molecules. In particular, Opitom’s team searched the ejecta for water molecules and for oxygen that could have come from the break-up of water molecules by the impact. However, no evidence of water was detected. Dimorphos, at least, seems to be a dry asteroid.

You can read the paper here.

Some theories prior to DART’s impact suggested that there could be ice within some inner solar system asteroids. Finding none instead suggests that inner solar system asteroids are very distinct and different from the icy comets and asteroids either coming from or orbiting in the outer solar system.

Scientists publish their results from the impact of Dimorphos by DART

Seconds after impact
Seconds after impact. Click for movie, taken by amateur
astronomer Bruno Payet from the Réunion Island.

Scientists today published five papers outlining their results from the impact of Dimorphos by DART, summed up as follows:

  • Dimorphos’s density is about half that of Earth’s, illustrating its rubble pile nature.
  • The orbital period around the larger asteroid Didymos was changed by 33 minutes.
  • The ejection of material from Dimorphos during the impact had a greater effect on the asteroid’s momentum than the impact itself
  • The mass ejected was only 0.3 to 0.5% of Dimorphos’s mass, showing that the asteroid was not destroyed by the impact.
  • The impact turned Dimorphos into an active asteroid, with a tail like a comet.

The data not only tells us a great deal about this asteroid binary itself, it suggests that this impact method might be of use in defending the Earth from an asteroid impact. There are caveats however. First, the orbital change was not to the system’s solar orbit, the path that would matter should an asteroid threaten the Earth, but to Dimorphos’s orbit around its companion asteroid. We don’t yet know the effect on the solar orbit. Second, the impact did not destroy this small rubble pile asteroid, which means such an asteroid might still be a threat to the Earth even after impact. Third, in order for an impact to be the right choice for planetary defense, detailed information about the target asteroid has to be obtained. Without it such an impact mission might be a complete waste of time.

The irony to all this is that we knew all this before the mission. DART in the context of planetary defense taught us nothing, so NASA’s claim that this mission was to learn more about planetary defense was always utter bunkum. The mission’s real purpose was the study of asteroids, but selling it that way was hard. The sizzle of planetary defense however was a better lobbying technique, and it worked, even if it was dishonest.

That the press was also fooled by it, and continues to be fooled by it, is a subject for a different essay.

For only 7th time, searchers find meteorite immediately after fall

For only 7th time, searchers on February 15th found a fragment of a meteorite that had only fallen to Earth three days before, and was furthermore only discovered mere hours before it entered the Earth’s atmosphere.

From the tweet of the discoverers:

FRIPON/Vigie-Ciel finds a fragment of asteroid 2023CX1 in Seine Maritime!!! The discovery was made by Loïs Leblanc, an 18-year-old student, part of the field research team.

Vigie-Ciel (“Sky Watchers”) and FRIPON are a volunteer project that searches for meteorites. The asteroid itself was discovered by Hungarian astronomer Krisztián Sárneczky while doing routine survey scan for near Earth asteroids.

The find was the second time Sárneczky has spotted an asteroid just hours before it broke apart in Earth’s atmosphere as a fireball, following an incredible find in March 2022.

By finding meteorites this quickly after arrival scientists get a more pristine sample, since the asteroid has not been exposed to the Earth’s environment for any extended length of time.

Astronomers find ring around distant dwarf planet Quaoar

The uncertainty of science: Astronomers have confirmed the existence of an uneven ring encircling the dwarf planet Quaoar, orbiting far enough from the planet that, according to present theories, the ring should have quickly coalesced into a small Moon.

At 1,110 km (690 miles) in diameter Quaoar is one of the largest objects known in the outer solar system. Its single moon, named Weywot, spans about 160 km and was discovered in Hubble images in 2007. But the first signs of material around Quaoar didn’t come until 2018; even then, evidence was insufficient to call it a ring, says Morgado. He began studying Quaoar in 2020 with the European Space Agency’s CHEOPS space telescope, originally designed to find and characterize exoplanets. Rather than looking for exoplanet transits, Morgado used CHEOPS to observe stellar occultations, when Quaoar passed in front of distant stars and momentarily blocked their light.

Now Morgado has extended his work, working with others to observe Quaoar’s stellar occultations using other telescopes. The team first predicted a few occultations and recorded them. Then, after those observations hinted at a ring, the researchers went back through previous occultation records. “We saw the ring in nine different regions, from observations taken between 2018 and 2021,” Morgado explains.

In Nature, the team reports the presence of a ring 4,100 kilometers from the center of Quaoar, far beyond its classical Roche limit of 1,780 km. Morgado says the ring is dense and irregular. “It has a very thin region about 5 km wide and also a large region about 300 km wide, depending on which part of the ring was probed,” he notes. If the material could all be collected into a single moon, it would be about 10 km in diameter, less than a tenth of Weywot’s size.

According to astronomers, they would expect such a ring at that distance to coalesce in just a matter of decades. Either their theories of the Roche limit are incorrect, or the creation of this ring is very very recent, caused by the collusion of two objects that were orbiting Quaoar.

Curiosity spots foot-wide meteorite on Mars

Meteorite on Mars?
Click for original image.

Curiosity appears to have identified a foot-wide rock on the surface of Mars that is likely a meteorite.

While the JPL press release at this link is certain this is a meteorite, the Curiosity science team is properly more circumspect:

The rock we are parked in front of is one of several very dark-colored blocks in this area which seem to have come from elsewhere, and we are calling “foreign stones.” Our investigations will help determine if this is a block from elsewhere on Mars that just has been weathered in an interesting way or if it is a meteorite.

The image to the right surely does look like a meteorite. If so, this would be one of the largest found so far on Mars by any rover.

Astronomers discover twelve more Jupiter moons

In reviewing ground-based data from 2021 and 2022, astronomers have discovered another twelve Jupiter moons, bringing that planet’s total moon population to 92.

All of the newly discovered moons are small and far out, taking more than 340 days to orbit Jupiter. Nine of the 12 are among the 71 outermost Jovian moons, whose orbits are more than 550 days. Jupiter probably captured these moons, as evidenced by their retrograde orbits, opposite in direction to the inner moons. Only five of all the retrograde moons are larger than 8 kilometers (5 miles); Sheppard says the smaller moons probably formed when collisions fragmented larger objects.

One newly discovered moon, dubbed Valetudo, is about 3,000 feet across and orbits in a retrograde orbit that crosses the orbits of several other moons that orbit in the opposite direction. As the article notes, “This highly unstable situation is likely to lead to head-on collisions that would shatter one or both objects.”

The twin asteroid Janus probes, stranded by Psyche delay, might go to Apophis

Apophis' path past the Earth in 2029
A cartoon showing Apophis’s path in 2029

The science team that built the twin Janus spacecraft, designed to fly past an asteroid but stranded when its launch got canceled, are now considering the potentially dangerous asteroid Apophis as a new target.

If the Janus spacecraft can find a ride by early 2028, scientists could use one or both of the spacecraft to scout out the large asteroid Apophis before its super-close approach to Earth in April 2029. (If only one spacecraft visits Apophis, scientists would see only about half of the asteroid but could send the second spacecraft elsewhere; if both spacecraft fly past the same object they can be arranged to reveal the whole surface.)

Initially the entire Janus mission had been designed on the assumption it would launch as a secondary payload when the Psyche mission to the asteroid Psyche launched last fall. When that launch had to be canceled because Psyche was not ready, Janus lost its mission. The science team has since been struggling to find a replacement, handicapped by the fact that it must go as a secondary payload.

There is a serious issue however with arriving ahead of Apophis’s close approach in 2029. The science community has discouraged such missions, because they fear a spacecraft arriving then could shift Apophis’s trajectory and actually increase the chance it will hit the Earth during a later close approach. Instead, all planetary probes presently going to Apophis in 2029 are planning to arrive after the flyby.

The risk is extremely small, but it must be considered before sending Janus to Apophis.

Lucy team adds 10th asteroid to the spacecraft’s tour

Lucy's route through the solar system
Lucy’s route through the solar system

The Lucy science team has now added a tenth asteroid to the spacecraft’s tour of the solar system, planning its route so that it will pass within 280 miles on November 1, 2023.

The Lucy mission is already breaking records by planning to visit nine asteroids during its 12-year tour of the Jupiter Trojan asteroids, which orbit the Sun at the same distance as Jupiter. Originally, Lucy was not scheduled to get a close-up view of any asteroids until 2025, when it will fly by the main belt asteroid (52246) Donaldjohanson. However, the Lucy team identified a small, as-yet unnamed asteroid in the inner main belt, designated (152830) 1999 VD57, as a potential new and useful target for the Lucy spacecraft.

The asteroid is about 2,300 feet wide. The primary goal of this visit however will be engineering, testing Lucy’s new method of tracking an object as the spacecraft flies past. On the map to the right the dots along Lucy’s path indicate the asteroids to be visited.

Lucy team suspends efforts to complete deployment of unlatched solar panel

Lucy's planned route
Lucy’s planned route to explore the Trojan asteroids

The Lucy science team has decided to suspend its efforts to complete the deployment of the unlatched solar panel that failed to fully open shortly after launch, having determined that little can be accomplished while the spacecraft is so far from the Sun.

A series of activities in 2022 succeeded in further deploying the array, placing it into a tensioned, but unlatched, state. Using engineering models calibrated by spacecraft data, the team estimates that the solar array is over 98% deployed, and it is strong enough to withstand the stresses of Lucy’s 12-year mission. The team’s confidence in the stability of the solar array was affirmed by its behavior during the close flyby of the Earth on Oct. 16, 2022, when the spacecraft flew within 243 miles (392 km) of the Earth, through the Earth’s upper atmosphere. The solar array is producing the expected level of power at the present solar range and is expected to have enough capability to perform the baseline mission with margin.

The team elected to suspend deployment attempts after the attempt on Dec. 13, 2022, produced only small movement in the solar array. Ground-based testing indicated that the deployment attempts were most productive while the spacecraft was warmer, closer to the Sun. As the spacecraft is currently 123 million miles (197 million km) from the Sun (1.3 times farther from the Sun than the Earth) and moving away at 20,000 mph (35,000 km/hr), the team does not expect further deployment attempts to be beneficial under present conditions.

The spacecraft will do another Earth fly-by on December 12, 2024, which will send it to the Trojans on the left side of the map above. Before that Lucy will do a mid-course correction in February 2024, at which time the engineers will reassess whether to try again to latch the panel, when Lucy is closer to Earth and thus also closer to the Sun.

NASA approves $1.2 billion asteroid-hunting space telescope

NASA has given the go-ahead to build NEO-Surveyor for $1.2 billion, more than twice the cost of its original proposal, to launch by 2028 and then look for potentially dangerous asteroids.

Notably, NEO Surveyor was earlier estimated to cost between $500 million and $600 million, or around half of the new commitment. The NASA statement said that the cost and schedule commitments outlined align the mission with “program management best practices that account for potential technical risks and budgetary uncertainty beyond the development project’s control.” Earlier this year, the project’s launch was delayed two years, from 2026, due to agency budget concerns.

The mission is designed to discover 90% of potentially Earth-threatening asteroids and comets 460 feet (140 meters) or larger that come within 30 million miles (48 million kilometers) of Earth’s orbit. The spacecraft will carry out the survey while from Earth-sun Lagrange Point 1, a gravitationally stable spot in space about 930,000 miles (1.5 million kilometers) inside the Earth’s orbit around the sun.

A prediction: It will cost more, and not launch on time. NASA’s decision to double the budget and delay the launch two years suggests it did not trust the JPL cost and time estimates. Based on most NASA-centered projects, however, it is likely the new numbers will still be insufficient.

Astronomers spot asteroid mere hours before it burned up in Earth’s atmosphere

For only the sixth time, astronomers this past weekend were able to image an asteroid just before it hit the Earth’s atmosphere and burned up over Canada.

The mini-asteroid, less than 3 feet (1 meter) wide, was spotted by astronomer David Rankin at Mount Lemmon Observatory in Arizona, according to SpaceWeather.com. Subsequent observations by other astronomers confirmed that the rock, coming from the direction of the main asteroid belt between the orbits of Mars and Jupiter, was on a collision course with Earth.

Only three hours after the first detection, the object, since dubbed C8FF042, sliced through the sky above Canada and landed in Lake Ontario, according to NASA.

While it is believed that most of the meteorite’s pieces that reached the ground fell into Lake Ontario, there is a chance some pieces might still be found along the south coast of the lake between Hamiliton and Niagara Falls.

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