Tag: asteroids

ULA’a Atlas-5 successfully launches the Lucy asteroid probe

6:08 pm

ULA’a Atlas-5 rocket early this morning successfully launched the Lucy asteroid probe on a 12 year mission to study eight Trojan asteroids over a period from 2025 to 2031. One tidbit about the mission is especially creative:

Scientists named the Lucy mission after the fossilized remains of a human ancestor, called Lucy by the scientists who discovered her in Ethiopia in 1974.

The leaders in the 2021 launch race:

36 China
23 SpaceX
17 Russia
4 Northrop Grumman
4 ULA

The U.S. and China are once again tied in the national rankings, at 36 each.

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New Horizons discovers two binary asteroids in Kuiper Belt

10:32 am

Overview map
Click for full map.

As New Horizons traveled from Pluto to the asteroid Arrokoth in 2018, scientists used it to take images of the relatively nearby asteroids that it was passing, and found that two of those asteroids appeared elongated.

[T]he team fit the shapes with a two-body model: two asteroids in a tight orbit. Even though the individual rocks weren’t resolved, the modeling showed that two bodies were better able to explain the elongation, as well as the brightness seen. The model for 2011 JY31 had two 50-km-wide objects nearly 200 km apart, while for 2014 OS393, the model had slightly smaller bodies (30 km across) that orbited each other 150 km apart.

The map, cropped and further annotated by me, shows New Horizons’ path during this time period, with the two binary asteroids indicated in blue.

This data, combined with the double lobe shape of Arrokoth (formerly named Ultima Thule), strongly suggests that it was not unusual for these primitives asteroids in the early solar system to coalesce from comparably sized partners.

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UAE to launch probe to asteroid belt

9:01 am

The new colonial movement: The United Arab Emirates (UAE) today announced that it is planning an unmanned probe to visit a number of asteroids in the asteroid belt.

The project targets a 2028 launch with a landing in 2033, a five-year journey in which the spacecraft will travel some 3.6 billion kilometers (2.2 billion miles). The spacecraft would need to slingshot first around Venus and then the Earth to gather enough speed to reach an asteroid some 560 million kilometers (350 million miles) away.

It appears they have not yet chosen their targets in the belt.

The big question will be how much of this project will be built in the UAE, and how much they will have to farm out to others. For their Al-Amal Mars orbiter, the satellite was mostly built by U.S. universities, as they trained UAE engineers, who now run the mission entire.

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Two nearby asteroids found with more precious metals than Earth’s entire global supply

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The precious metals on asteroid 1986 DA, compared to the world's reserves

Capitalism in space: Astronomers have now identified two metal-rich asteroids in orbit near the Earth, with one having a precious metal content that likely exceeds the Earth’s entire reserves.

From the paper’s conclusion:

We estimated that the amounts of Fe, Ni, Co, and the PGM present in 1986 DA could exceed the reserves worldwide. Moreover, if 1986 DA is mined and the metals marketed over 50 yr, the annual value of precious metals for this object would be ∼$233 billion.

The graphic to the right, figure 13 from the paper, illustrates the amount of precious metals available in asteroid 1986 DA, compared to the world’s entire reserves (FE=iron, Ni=nickel, Co=cobalt, Cu=copper, PGM=platinum group metals, Au=gold). From this single metal asteroid a mining operation could literally double the metal that had been previously mined on Earth.

In estimating the value of these metals, the paper tries to account for the certain drop in price caused by the flooding of so much material into the market. It is a guess however. What is clear is that this asteroid could easily serve as a supply house not for Earth but for all future colonies in space. While expensive for Earth use, for colonies already in space the material would be relatively easy to reach and mine. The colonies will already have the transportation infrastructure, since they couldn’t exist without rockets and interplanetary spacecraft. And mining and processing this asteroid material will be far easier and cheaper than trying to find it on Mars and then process it.

Asteroid 1986 DA is estimated to be about 1.7 miles across, based on radar data obtained during a close Earth fly-by in 2019. The second asteroid, 2016 ED85, appears to have a similar content from spectroscopy, but no radar data has as yet been obtained of it, so much less is known.

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Biden signs budget continuing resolution, preventing shutdown

9:00 am

At the very last second Congress and President Biden passed and signed another budget continuing resolution that will keep the federal government operating till December and thus preventing another shutdown.

From NASA’s narrow perspective, the action means that the asteroid mission Lucy will likely launch in October as planned. From the perspective of the nation, this last second action merely illustrates the overall failure of the federal government and the elected officials who have been tasked to run it. They are all incompetent, and wouldn’t last five seconds in a real job outside the government.

That the voters keep re-electing them also speaks poorly of America today. We all should be ashamed.

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Orbit of biggest comet ever detected refined

10:59 am

Astronomers have now been able to better refine the orbit and size of Comet Bernardinelli-Bernstein, comet with the largest nucleus ever detected.

A new analysis, led by Bernardinelli and Bernstein themselves, found that the comet nucleus is around 150 km wide, based on its brightness. If so, that makes it the largest comet ever discovered, by quite a margin. Most are only a few kilometers to several dozen kilometers wide, while some particularly big ones, like Hale-Bopp, may be up to 80 km (50 miles) wide. The previous record-holder, Sarabat’s Comet of 1729, has been estimated at about 100 km wide.

The team was also able to calculate the orbit of Comet BB in more detail. This object is on an incredibly long round trip into and out of the solar system – at its most distant point, some 1.5 million years ago, it was about 40,400 AU away. Last time it swung through our neighborhood was about 3.5 million years ago, when it came within 18 AU of the Sun.

But its current inward journey will be its closest so far. Astronomers have already calculated that in 2031, Comet BB will peak at 10.9 AU, almost reaching the orbit of Saturn.

It is presently unclear how bright the comet will be when it reachest its closest point. It will be much farther from the Sun than most bright comets, but its large size may change what is normally expected.

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Government shutdown threatens Lucy asteroid mission

9:00 am

Government marches on! The possibility that the federal government could shut down because of the inability of Congress and the Biden administration to pass a funding bill or raise the debt limit now threatens the launch of the Lucy mission to the asteroid belt.

If no budget agreement is reached the government will shut down on October 1st. If the debt limit isn’t raised that shutdown could follow soon thereafter, even if a budget is passed.

The launch window for the mission is from October 16 to November 7, 2021. If the spacecraft does not launch in that window the science team says it will likely require a major rethinking of the entire project, as it will be difficult to find another opportunity to visit the same set of asteroids.

Right now the chances of a shutdown are very high, as the Democrats are pushing big spending bills without any negotiations with the Republicans. In answer, the Republican caucus has said that none of its members will support raising the debt limit. Without the latter any passed spending bill will soon be moot, as the debt limit will soon be reached, blocking further government spending.

Though I personally would be very saddened if Lucy was prevented from launching, that loss would be well compensated for by having the federal government out of business. The evil and corruption promoted by it far outweighs the good work done by several minor space missions.

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China’s Chang’e-5 orbiter returning to lunar space

9:25 am

The new colonial movement: In a somewhat bold move, Chinese engineers appear to now be shifting the Chang’e-5 orbiter so that it will be able to return to lunar space to fly past the Moon.

The orbiter, one of four distinct Chang’e-5 mission spacecraft, delivered a return module containing 1.731 kilograms of lunar samples to Earth Dec. 16 before firing its engines to deep space for an extended mission.

The Chang’e-5 orbiter later successfully entered an intended orbit around Sun-Earth Lagrange point 1, roughly 1.5 million kilometers, in March. There it carried out tests related to orbit control and observations of the Earth and Sun.

New data from satellite trackers now suggests Chang’e-5 has left its orbit around Sun-Earth L1 and is destined for a lunar flyby early September 9 Eastern time.

This data comes not from China but from amateur astronomers who specialize in tracking satellites.

The fly-by could provide the spacecraft the velocity it needs to reach near Earth asteroid Kamo’oalewa, which China has said it is targeting for a 2024 sample return mission. Such a reconnaissance will help them design the sample return mission.

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First hi-res radio wavelength images of metal asteroid Psyche

9:46 am

Psyche in thermal

Using the ALMA telescope in Chile astronomers have obtained the highest resolution radio images of the surface of the metal-rich asteroid Psyche yet obtained. The image to the right is from their just published paper. From the article:

These new images reveal that some regions of the asteroid have surface temperatures different from the average, indicating that Psyche’s composition is not uniform. The researchers also found that Psyche has a relatively high thermal inertia compared to other asteroids, yet it radiates approximately 60% less heat than would be expected for an object with such a high inertia. The researchers hypothesize that this is because the asteroid’s surface is at least 30% metal. However, the light reflecting off Psyche’s surface is unpolarized, which would not be the case for an object with a smooth or solid metallic surface. They therefore hypothesize that metallic grains are spread throughout its surface material, causing the light to scatter.

Though Psyche is large, 178 by 144 by 101 miles, it is not spherical like Ceres, the largest asteroid in the asteroid belt at 580 miles diameter. Thus, somewhere from the size of Psyche to the size of Ceres we move from an irregular asteroid body to a spherical planetary body, as it appears most planetary scientists define planets.

The probe Psyche is scheduled to launch in August ’22 to arrive at Psyche in ’26.

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Asteroid discovered with shortest orbit yet

8:55 am

Astroid's orbit
Click for full image.

Astronomers have discovered an asteroid that circles the Sun with the shortest orbit yet found, flying mostly inside the orbit of Mercury.

The illustration to the right shows the asteroids orbit, which is also tilted 32 degrees from the plane of the solar system.

The orbit of the approximately 1-kilometer-diameter asteroid takes it as close as 20 million kilometers (12 million miles or 0.13 au), from the Sun every 113 days. Asteroid 2021 PH27, revealed in images acquired during twilight, also has the smallest mean distance (semi-major axis) of any known asteroid in our Solar System — only Mercury has a shorter period and smaller semi-major axis. The asteroid is so close to the Sun’s massive gravitational field, it experiences the largest general relativistic effects of any known Solar System object.

Relatively few asteroids have been found with orbits shorter than Earth’s, because to find them astronomers have to turn their telescopes sunward, where viewing is limited to the early evening or early morning. Few space-based telescopes in all wavelengths also don’t look this way much, because of the risk of damage from the intense sunlight.

It is thus unknown exactly how many asteroids exist with similar orbits. There may be many, with many having short eccentric orbits, similar to comets, that extend out to Earth’s orbit and thus pose a risk. Or there may be few, since such orbits so close to the Sun are likely to cause the asteroid’s break-up and destruction over time.

Knowing how many of course is important, in order to obtain a full census of those asteroids in the solar system that might hit the Earth. To get it will likely require placing a probe designed to look for them.

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China to fly asteroid sample mission in ’24

9:19 am

The new colonial movement: Chinese scientists have revealed that China is now building an asteroid sample mission to launch in ’24 and grab samples in ’25 from the near Earth asteroid dubbed Kamoʻoalewa.

According to a correspondence in Nature Astronomy, there are two typical approaches to sampling asteroids like Kamoʻoalewa, namely anchor-and-attach and touch-and-go.

The former requires delicate and dangerous interactions with the planetary body but allows more controllable sampling and more chances for surface analysis. The latter, used by Hayabusa 2 and OSIRIS-Rex, is a quick interaction facilitated by advanced navigation, guidance and control and fine control of thrusters.

China’s mission will use both architectures in order to “guarantee that at least one works.” The paper states that there is “still no successful precedent for the anchor-and-attach architecture,” meaning a possible deep space first. A 2019 presentation reveals that China’s spacecraft will attempt to land on the asteroid using four robotic arms, with a drill on the end of each for anchoring.

The attempt to do both these approaches is audacious, especially because the evidence from both OSIRIS-REx and Hayabusa-2 is that it will be difficult to safely land and hold onto a rubble pile asteroid. The material is too loosely held together.

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OSIRIS-REx scientists refine Bennu’s future Earth impact possibilities

1:28 pm

Using the orbital and gravity data compiled during OSIRIS-REx’s visit to the asteroid Bennu, scientists have refined its future orbits as well as the most likely moments it might impact the Earth.

In 2135, asteroid Bennu will make a close approach with Earth. Although the near-Earth object will not pose a danger to our planet at that time, scientists must understand Bennu’s exact trajectory during that encounter in order to predict how Earth’s gravity will alter the asteroid’s path around the Sun – and affect the hazard of Earth impact.

Using NASA’s Deep Space Network and state-of-the-art computer models, scientists were able to significantly shrink uncertainties in Bennu’s orbit, determining its total impact probability through the year 2300 is about 1 in 1,750 (or 0.057%). The researchers were also able to identify Sept. 24, 2182, as the most significant single date in terms of a potential impact, with an impact probability of 1 in 2,700 (or about 0.037%).

Although the chances of it hitting Earth are very low, Bennu remains one of the two most hazardous known asteroids in our solar system, along with another asteroid called 1950 DA.

This paper’s conclusions are confirming what had been found earlier in the mission, while OSIRIS-REx was still flying in formation with the asteroid. Nonetheless, it is essential to refine these numbers as precisely as possible, so this confirmation is excellent news.

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Comet spewed out an unusual amount of alcohol during solar flyby

1:04 pm

A review of the data gathered when Comet 46P/Wirtanen made its close fly-by of the Sun in 2018 has found that the comet released an unusual amount of alcohol during that flyby.

The data also showed that the temperature of the comet’s coma did not cool as much as expected at larger distances from the comet.

“46P/Wirtanen has one of the highest alcohol-to-aldehyde ratios measured in any comet to date,” said Neil Dello Russo, a cometary scientist at Johns Hopkins University Applied Physics Laboratory and co-author of the study. “This tells us information about how carbon, oxygen, and hydrogen molecules were distributed in the early solar system where Wirtanen formed.”

Keck Observatory data also revealed a strange characteristic. Normally, as comets orbit closer to the Sun, the frozen particles in their nucleus heat up, then boil off, or sublimate, going directly from solid ice to gas, skipping the liquid phase. This process, called outgassing, is what produces the coma – a giant cloak of gas and dust glowing around the comet’s nucleus. As the comet gets even closer to the Sun, solar radiation pushes some of the coma away from the comet, creating the tails.

With comet 46P/Wirtanen however, the team made a strange discovery: Another process beyond solar radiation is mysteriously heating up the comet.

“Interestingly, we found that the temperature measured for water gas in the coma did not decrease significantly with distance from the nucleus, which implies a heating mechanism,” said co-author Erika Gibb, professor and chair of the Department of Physics and Astronomy at University of Missouri–St. Louis.

They have theories about why they got these results, such as a chemical reaction with sunlight or the presence of large ice chunks breaking off the comet that reflect light and increase the ambient temperature of the coma. Nothing is confirmed however.

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Astronomers discover “comet” bigger than the largest comets approaching inner solar system

9:25 am

Astronomers have discovered an object 80 to 100 miles in diameter, larger than the largest comets, approaching the inner solar system and coming from the theorized Oort Cloud of material thought to exist between a tenth and a third of a light year from the Sun.

The object is probably rich in ice like a comet and is currently around three billion kilometres from the Sun. It will reach its closest point, known as perihelion, in 2031. At that time, it will be positioned below the plane of the solar system, near the orbit of Saturn.

Part of the interest in C/2014 UN271 is that it may be something of a transition object. Astronomers believe that many of the long period comets, that occasionally appear with bright tails, actually come from the Oort Cloud. Stars wandering near the Sun can nudge these objects from their positions and over millennia they work their way inwards, with the gravity of the giant planets tweaking their paths on each visit until they reside where we see them today.

“The fact that [C/2014 UN271] has a perihelion so far away from the Sun might be telling us that it’s done this a couple of times but is still in that process of eventually becoming some of those long period comets we know and love,” explains Meg Schwamb a Kuiper Belt and Oort Cloud expert at Queen’s University Belfast.

Initially astronomers thought because of its size that it was not a comet, but new observations have detected the first signs of a coma, suggesting that it will provide us a very interesting and extended show when it reaches its closest point in 2031. Because that perihelion is around the orbit of Saturn, the object will not be traveling very fast, so its passage through the inner solar system will take several years. Its size also suggests it will have a lot of material that can sublimate off to produce a tail.

The object was discovered by two astronomers, Gary Bernstein and Pedro Bernardinelli. If it turns out to be a comet it will then be named Comet Bernardinelli-Bernstein, or Comet B-B for short.

UPDATE: It is official. The object is now officially a comet, and named Comet Bernardinelli-Bernstein.

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Japanese scientists complete inventory of Ryugu asteroid samples

9:00 am

In a press conference yesterday the Japanese space agency JAXA announced that scientists have completed their inventory of the samples brought back from the asteroid Ryugu by the Hayabusa-2 spacecraft, and are now ready to begin distributing those samples to scientists around the world for more detailed research.

JAXA has cataloged the soil samples brought back by Hayabusa 2 last December, by size, color and shape. From now, 269 researchers from 14 countries, including Japan and the United States, will conduct an in-depth analysis of the soil’s structures and components over the course of about a year.

As expected, the inventory found the samples had a large amount of hydrogen, oxygen, and carbon atoms. Even before Hayabusa-2’s arrival, Ryugu had been catalogued as a “hydrated” asteroid, which means it was thought to contain a lot of hydrogen and oxygen, the basic elements of water. The inventory has now confirmed this.

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Ryugu’s most primitive boulders

1:18 pm

In a just published paper scientists reveal how they think they have identified the oldest rocks on the rubble pile asteroid Ryugu, and found them to be distributed across the entire face of the asteroid.

These boulders are light enough that they would float on water.

Ryugu is thought to have initially formed as a fluffy planetesimal that coalesced from accumulated dust in the early Solar System, and subsequently underwent processes such as thermal evolution and compression. This parent body was then later destroyed in a collision and fragments of this reaccumulated into the asteroid. However, planetesimals have never been seen, so whether they really existed or what they may have looked like is one of the biggest challenges in understanding the planet formation process. The boulders discovered in this research are thought to be a material that most strongly retains the appearance of the fluffy planetesimals that triggered the birth of the planets in the Solar System.

Additionally, the data from all the scientific instruments onboard Hayabusa2 that were used to examine the surface of Ryugu revealed that fragments of material similar to those of the ultra-high porosity boulders are globally distributed over the asteroid surface, and may have been collected in the sample taken by Hayabusa2. If highly primitive material with the ultra-high porosity discovered here is also found in the collected samples, it will both clarify the formation and evolutional history of Ryugu’s parent body, and also provide evidence of planetesimal formation in the early stage of the Solar System formation process.

There is no word yet from the scientists studying the Hayabusa-2 samples on what they have found. This paper gives them an idea of what could be the most important type of rock to look for.

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OSIRIS-REx on its way back to Earth

10:54 pm

OSIRIS-REx today fired its engines and successfully put itself on course for returning its samples from the asteroid Bennu to Earth on September 24, 2023.

The May 10 departure date was precisely timed based on the alignment of Bennu with Earth. The goal of the return maneuver is to get the spacecraft within about 6,000 miles (approximately 10,000 kilometers) of Earth in September 2023. Although OSIRIS-REx still has plenty of fuel remaining, the team is trying to preserve as much as possible for a potential extended mission to another asteroid after returning the sample capsule to Earth. The team will investigate the feasibility of such a mission this summer.

The spacecraft’s course will be determined mainly by the Sun’s gravity, but engineers will need to occasionally make small course adjustments via engine burns.

The science team has already proposed one option, sending the spacecraft on a rendezvous with the potentially dangerous asteroid Apophis shortly after its 2029 close-fly of Earth. It could be that there are other targets as interesting that they need to choose from.

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New OSIRIS-REx photos of Bennu sample site after sample grab

1:40 pm

Nightingale before and after sample grab
Click here and here for original images.

The OSIRIS-REx science team today released the photos the spacecraft obtained in its last fly-by of the asteroid Bennu on April 7th of the Nightngale sample site, showing how it changed after the sample grab in October 2020.

The two photos to the right compare that site, with the top image taken before the sample grab and the bottom image taken on April 7th.

Comparing the two images reveals obvious signs of surface disturbance. At the sample collection point, there appears to be a depression, with several large boulders evident at the bottom, suggesting that they were exposed by sampling. There is a noticeable increase in the amount of highly reflective material near the TAG [touch-and-go] point against the generally dark background of the surface, and many rocks were moved around.

Where thrusters fired against the surface, substantial mass movement is apparent. Multiple sub-meter boulders were mobilized by the plumes into a campfire ring–like shape — similar to rings of boulders seen around small craters pocking the surface.

Jason Dworkin, the mission’s project scientist at NASA’s Goddard Space Flight Center in Greenbelt, Maryland, noticed that one boulder measuring 4 feet (1.25 meters) across on the edge of the sampling site seemed to appear only in the post-TAG image. “The rock probably weighs around a ton, with a mass somewhere between a cow and a car.”

Dante Lauretta, of the University of Arizona and the mission’s principal investigator, later pointed out that this boulder is likely one of those present in the pre-TAG image, but much nearer the sampling location, and estimates it was thrown a distance of 40 feet (about 12 meters) by the sample collection event.

The sample grab arm penetrated the surface by more than a foot, and that event is marked by that dark depression at the center of the site.

OSIRIS-REX will now prepare for its May 10th engine firing that will send it on its route back to Earth to return that sample in September 24, 2023. After that the spacecraft could be sent on another mission, this time to the potentially dangerous asteroid Apophis.

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OSIRIS-REx completes last close-fly of Bennu

12:39 pm

OSIRIS-REx today successfully completed its last close-fly of Bennu before it will fire its engines on May 10th and begin its journey back to Earth to return its samples.

During the flyby, OSIRIS-REx imaged Bennu for 5.9 hours, covering more than a full rotation of the asteroid. It flew within 2.1 miles’ (3.5 kilometers) distance to the surface of Bennu – the closest it’s been since the TAG sample collection event.

It will take until at least April 13 for OSIRIS-REx to downlink all of the data and new pictures of Bennu’s surface recorded during the flyby. It shares the Deep Space Network antennas with other missions like Mars Perseverance, and typically gets 4–6 hours of downlink time per day. “We collected about 4,000 megabytes of data during the flyby,” said Mike Moreau, deputy project manager of OSIRIS-REx at NASA’s Goddard Space Flight Center in Greenbelt, Maryland. “Bennu is approximately 185 million miles from Earth right now, which means we can only achieve a downlink data-rate of 412 kilobits per second, so it will take several days to download all of the flyby data.”

While they will get images of the asteroid’s entire surface, the region scientists are most interested in is the Nightingale sample return site where the spacecraft grabbed its samples. To best understand the asteroid they need to have before and after shots, and this last fly-by gave them the latter.

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Radar images of Apophis during its March close approach of Earth

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Apophis as seen by radar March 9, 2021
Click for full image.

Using two radar dishes, Green Bank in West Virginia and Goldstone in California, astronomers were able to produce radar images of the asteroid Apophis during its most recent close fly-by of Earth on March 10th.

The image to the right, cropped and reduced to post here, shows Apophis on March 9th. If you go to the full image you can also see the March 10th and 11th images, which appear to show the asteroid in different orientations as it rotated.

These images represent radar observations of asteroid 99942 Apophis on March 8, 9, and 10, 2021, as it made its last close approach before its 2029 Earth encounter that will see the object pass our planet by less than 20,000 miles (32,000 kilometers). The 70-meter radio antenna at the Deep Space Network’s Goldstone Deep Space Communications Complex near Barstow, California, and the 100-meter Green Bank Telescope in West Virginia used radar to precisely track Apophis’ motion. At the time of these observations, Apophis was about 10.6 million miles (17 million kilometers) from Earth, and each pixel has a resolution of 127 feet (38.75 meters).

The data obtained has firmly removed any chance Apophis will impact the Earth in the next 100 years. However, it still could hit us late in the 22nd century.

These observations were originally planned to also include data from the Arecibo Observatory, but that telescope was destroyed in December when its instrument platform collapsed. If it had been operational, these radar images would have had much better resolution.

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Meteorite recovered in driveway in UK only days after landing

9:18 am

Meteorite hunters successfully recovered a meteorite only days after it plowed through the atmosphere and landed in a driveway in Gloucestershire in the United Kingdom on February 28th.

The fragment, weighing nearly 300 grams, and other pieces of the space rock were located after scientists reconstructed the flight path of the fireball that unleashed a sonic boom as it tore across the sky shortly before 10pm UK time on Sunday 28 February. The black chunk of rock, a carbonaceous chondrite never seen before in the UK, thumped on to a driveway in the Cotswolds town of Winchcombe, scientists at the Natural History Museum in London said, adding that further fragments were retrieved nearby.

Ashley Green, a scientist at the museum, said it was “a dream come true” to be one of the first people to see and study a meteorite that had been recovered almost immediately after coming down.

Footage of the bright streak captured by the public, and a camera network operated by the Natural History Museum’s UK Fireball Alliance, helped researchers calculate that the meteor had spent most of its orbit between Mars and Jupiter before it ploughed into Earth’s atmosphere.

I seriously doubt that no carbonaceous chondrite asteroids have never been found in Great Britain before. Instead, what the reporter misunderstood was that this was the first such asteroid in the UK recovered immediately after its arrival. Carbonaceous chondrites are very fragile. Much of their material will quickly erode and disappear, preventing researchers from obtaining a complete census of their entire make-up. Grabbing this thing mere days after landing means they will have a sample more closely resembling these kinds of asteroids in space.

In this way this rock is not much different than the samples being brought back from Hayabusa-2 and OSIRIS-REx. It isn’t as pristine, but it certainly carries far more information that meteorites recovered decades or even centuries after landing.

Similar quick recoveries in the past few years have forced some major rethinking about the make-up of the asteroid population. This meteorite will likely add to that revolution.

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OSIRIS-REx begins last approach of Bennu

9:12 am

Approaching Bennu for the last time
Click for full image.

The science team for OSIRIS-REx released today the first picture taken as the spacecraft begins its last approach of the asteroid Bennu. To the right is that picture, cropped and expanded to post here. From the caption:

This image shows a top-down view of asteroid Bennu, with a portion of the asteroid’s equatorial ridge and northern hemisphere illuminated. It was taken by the PolyCam camera on NASA’s OSIRIS-REx spacecraft on March 4, from a distance of about 186 miles (300 km). The spacecraft’s cameras are pointed directly at Bennu’s north pole. Two large equatorial craters are visible on the asteroid’s edge (center and center left).

If all goes well, the probe will fly past the asteroid on April 7th, obtaining high resolution images of its entire surface as it rotates below, including very close-up images of the Nightingale sample grab location during its closest approach.

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Scientists confirm distance to farthest known solar system object

2:46 pm

Scientists have now confirmed that the large asteroid dubbed Farfarout (about 250 miles across) is presently about 132 astronomical units from the Sun (about 12 billion miles), making it the farthest known solar system object.

Its orbit however is far from circular, and it isn’t presently even at its farthest point in that orbit.

[T]he orbit of Farfarout is quite elongated, taking it 175 au from the Sun at its farthest point and around 27 au at its closest, which is inside the orbit of Neptune. Because its orbit crosses Neptune’s, Farfarout could provide insights into the history of the outer Solar System. “Farfarout was likely thrown into the outer Solar System by getting too close to Neptune in the distant past,” said Trujillo. “Farfarout will likely interact with Neptune again in the future since their orbits still intersect.”

The astronomers expect to discover more such objects in the coming years that will even eclipse this one in distance.

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OSIRIS-REx has begun its return to Bennu

2:17 pm

On January 14th the OSIRIS-REx team fired the spacecraft’s engines to halt its drift away from the asteroid Bennu and begin its return for one last reconnaissance before heading to Earth with its samples.

OSIRIS-REx executed the first maneuver on Jan. 14, which acted as a braking burn and put the spacecraft on a trajectory to rendezvous with the asteroid one last time. Since October’s sample collection event, the spacecraft has been slowly drifting away from the asteroid, and ended up approximately 1,635 miles (2,200 km) from Bennu. After the braking burn, the spacecraft is now slowly approaching the asteroid and will perform a second approach maneuver on Mar. 6, when it is approximately 155 miles (250 km) from Bennu. OSIRIS-REx will then execute three subsequent maneuvers, which are required to place the spacecraft on a precise trajectory for the final flyby on Apr. 7.

OSIRIS-REx is scheduled to depart Bennu on May 10 and begin its two-year journey back to Earth. The spacecraft will deliver the samples of Bennu to the Utah Test and Training Range on Sep. 24, 2023.

While they will gather images of the whole asteroid, their number one goal will be to get high resolution photos of the sample-grab site Nightingale to see how it was changed by that sample grab. The spacecraft pushed into the asteroid’s rubble pile about 1.6 feet, and that act certainly disturbed both the interior and surface. By comparing the before and after pictures scientists can garner a lot of information about the asteroid’s make-up, density, and structure. It will also teach future engineers what to expect when next they try to touch another rubble-pile asteroid.

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New radar technology now available for radio astronomy

9:47 am

GreenBank radar image of Apollo 15 landing region

Astronomers have now demonstrated a spectacular new radar technology using radio telescopes and capable of producing high resolution images of all solar system bodies, as far away as Neptune.

[S]cientists built a miniature transmitter, powered at less than a kilowatt and about the size of a refrigerator, Beasley said, and in November hauled it up for a brief stint at the prime focus of Green Bank Telescope, suspended over the large dish.

Then, the team took advantage of the telescope’s superlative: It’s the largest fully steerable radio telescope in the world, able to study objects across 85% of the sky. So the team pointed the telescope and fired the radar system at the moon — more specifically, at the Apollo 15 mission’s landing site in the Hadley-Apennine region [the white dot in the image to the right]. The team used antennas of the NRAO’s Very Long Baseline Array (VLBA) to catch the signal that bounced back.

The image, with its sloping hills, stark crater and slinking rille, offers a hint of what could come. But the moon is our old companion. Scientists would much rather use a shiny new planetary radar system to study more mysterious objects, like the asteroids zipping through our neighborhood of the solar system, most of which are blurs and blobs, or the strange moons of the outer planets that have received few spacecraft visitors.

Without question this technology would be a major breakthrough for the observation of asteroids, especially those that are considered a threat of impacting the Earth for which we have little concrete information.

The article however notes that the technology had been developed with the assumption that the Arecibo radio telescope would be available. That telescope however is now dead, having been destroyed when its instrument platform fell in early December. With a limited number of radio telescopes available, all of which are oversubscribed for other work, it will be difficult to find time for the use of this technology on any of them.

But don’t worry. The Chinese will definitely want to steal it and put it on their giant FAST radio telescope, and I am sure the Biden administration will be agreeable to letting them.

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OSIRIS-REx to make one last observation of Bennu before heading back to Earth

10:56 am

The OSIRIS-REx science team has figured out a way to make one last observation of Bennu and the Nightingale sample return site before heading back to Earth on May 10th.

This activity was not part of the original mission schedule, but the team is studying the feasibility of a final observation run of the asteroid to potentially learn how the spacecraft’s contact with Bennu’s surface altered the sample site. If feasible, the flyby will take place in early April and will observe the sample site, named Nightingale, from a distance of approximately 2 miles (3.2 kilometers). Bennu’s surface was considerably disturbed after the Touch-and-Go (TAG) sample collection event, with the collector head sinking 1.6 feet (48.8 centimeters) into the asteroid’s surface. The spacecraft’s thrusters also disturbed a substantial amount of surface material during the back-away burn.

The mission is planning a single flyby, mimicking one of the observation sequences conducted during the mission’s Detailed Survey phase in 2019. OSIRIS-REx would image Bennu for a full rotation to obtain high-resolution images of the asteroid’s northern and southern hemispheres and equatorial region. The team would then compare these new images with the previous high-resolution imagery of Bennu obtained during 2019.

Getting at look at Nightingale post-sample-grab is critical to better understanding the nature of the asteroid. Knowing how much changed from that contact will tell scientists a lot about the density, interior, and surface of this rubble-pile asteroid.

This last flyby will also give them the chance to assess the spacecraft’s equipment following the touch-and-go sample grab. They want to know if everything still works as designed in order to plan any post-Bennu missions, including the possibility that OSIRIS-REx will rendezvous with the asteroid Apophis in ’29, shortly after the asteroid makes its next close flyby of Earth.

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Hayabusa-2 begins journey to two asteroids

7:59 am

On January 5, 2021, after successfully delivering its samples of Ryugu to Earth, Hayabusa-2 fired up its ion engines and began its ten-year journey to two different asteroids.

Hayabusa2’s first extended-mission destination is the roughly 2,300-foot-wide (700 meters) asteroid (98943) 2001 CC21, which the probe will fly by at high speed in 2026, if all goes according to plan. A more in-depth rendezvous with yet another space rock, 1998 KY26, is scheduled to follow in 2031.

In a previous post I had mistakenly left out the first target asteroid. However, their primary target remains the tiny 100-foot-wide 1998 KY26, since it is so small. This will be the first close-up view of such a small asteroid, in space. Since such asteroids are many, it will tell us much about the make-up and history of the solar system.

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First look at Ryugu samples

8:55 am

Japanese scientists have taken their first look at the Ryugu sample material brought back by Hayabusa-2 and found they resemble charcoal.

The samples Japanese space officials described Thursday are as big as 1 centimeter (0.4 inch) and rock hard, not breaking when picked up or poured into another container. Smaller black, sandy granules the spacecraft collected and returned separately were described last week.

…The sandy granules the Japan Aerospace Exploration Agency described last week were from the spacecraft’s first touchdown in April 2019.

The larger fragments were from the compartment allocated for the second touchdown on Ryugu, said Tomohiro Usui, space materials scientist. To get the second set of samples in July last year, Hayabusa2 dropped an impactor to blast below the asteroid’s surface, collecting material from the crafter so it would be unaffected by space radiation and other environmental factors.

Usui said the size differences suggest different hardness of the bedrock on the asteroid. “One possibility is that the place of the second touchdown was a hard bedrock and larger particles broke and entered the compartment.”

The analysis of these samples has only just begun. Dating them is likely next, and that will probably reveal some startling results.

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Samples from space!

9:16 am

Scientists from both the Japanese Hayabusa-2 mission to the asteroid Ryugu and the Chinese Chang’e-5 mission to the Moon announced yesterday the total amount of material they successfully recovered.

The numbers appear to diminish the Japanese success, but that is a mistake. Getting anything back from a rubble-pile asteroid that had never been touched before and is much farther away from Earth than the Moon was a very great achievement. The 5.4 grams is also more than fifty times the minimum amount they had hoped for.

This is also not to diminish the Chinese achievement, They not only returned almost four pounds, some of that material also came from a core sample. They thus got material both from the surface and the interior of the Moon, no small feat from an unmanned robot craft.

Scientists from both nations will now begin studying their samples. Both have said that some samples will be made available to scientists from other countries, though in the case of China it will be tricky for any American scientist to partner with China in this research, since it is by federal law illegal for them to do so.

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Subaru Telescope photographs Hayabusa-2’s next target asteroid

2:09 pm

In order to better constrain its orbit, the Subaru Telescope in Hawaii has obtained new photographs of Hayabusa-2’s next target asteroid, 100-foot-wide 1998 KY26.

This asteroid is predicted to approach to within 0.47 AU of Earth in mid to late December 2020, giving us a rare opportunity that comes only once every three and a half years. However, the diameter of 1998 KY26 is estimated to be no more than 30 meters, and thus its brightness is so dim that ground-based observations of the asteroid are difficult without a very large telescope.

The observations with the Subaru Telescope were conducted upon the request of the Institute for Space and Astronautical Science (ISAS), JAXA. And as a result, 1998 KY26 was photographed in the direction of the constellation Gemini as a 25.4-magnitude point of light with a measurement uncertainty of 0.7 mag. The positional data collected during these observations will be used to improve the accuracy of the orbital elements of the asteroid. Similar observations were conducted with the Very Large Telescope (VLT) of the European Southern Observatory (ESO).

If all goes right Hayabusa-2 will rendezvous with 1998 KY26 in the summer of 2031.

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