Name: NASA gets ready to land on asteroid Bennu as new studies confirm it is a rich source of carbon - ABC News
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NASA gets ready to land on asteroid Bennu as new studies confirm it is a rich source of carbon - ABC News

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NASA gets ready to land on asteroid Bennu as new studies confirm it is a rich source of carbonShareIt may look like a grey space rock, but the asteroid known as Bennu is turning out to be far from boring.Later this month, a NASA spacecraft will land on this lumpy rock and suck up some dirt from its surface to bring back to Earth.The OSIRIS-REx probe has been circling the small asteroid between Earth and Mars preparing for this moment.When the spacecraft first sidled up to Bennu in 2018 it found the fast-spinning diamond-shaped rock was and there was evidence of on its surface. Now, six new papers in the journals Science and Science Advances provide even more detail about what the asteroid looks like — — and what the space dirt may contain.And there are several surprises, said Hannah Kaplan of NASA's Goddard Space Flight Center, who led one of the studies."We found things we didn't expect and could never have seen from Earth," Dr Kaplan said."In fact, we didn't even really see them until we were approaching the asteroid, we had to be there right up close."Bennu is a fragment from a much larger parent asteroid that was destroyed in a cataclysmic collision.This little pile of rubble is a type of asteroid known as a carbonaceous chondrite.And it's a time capsule that can help us decipher how the solar system formed.One of the main goals of the mission is to bring back a pristine sample of dirt that includes organic carbon — carbon-based chemicals that are the basis of life."We are especially interested in the organic carbon because the idea is that asteroids very similar to Bennu could have delivered some of these organic compounds to early Earth," Dr Kaplan explained.The latest studies confirm . But that's not all.Bennu also has — large dark crumbly ones that appear to contain a lot of organic material, and hard bright ones that contain other types of minerals.The NASA mission will collect space dirt from a location called Nightingale Crater, a small crater within a crater near the north pole.Dr Kaplan's research found that set against the dark carbon deposits in this area are brighter rocks that contain — a type of carbon that has been altered by water. "We think these veins formed on the parent body — not on Bennu itself very early on in solar system history at a time when there was water flowing through the [original] asteroid," she said.The size of the veins, some of which are up to a metre thick, indicates that large volumes of water flowed through the original asteroid for thousands to millions of years.Over time, Bennu has been bombarded by solar wind and micrometeorites, including pebble-sized particles trapped by its raining down on the surface.When researchers analysed light reflected from the asteroid they found these bombardments had altered the chemistry of the surface of the asteroid making it in different wavelengths of light."This is not something we were expecting," said Dani DellaGiustina, the OSIRIS-REx lead imager based at University of Arizona.But some areas, such as Nightingale Crater, are redder.A red crater signifies an area that has only been exposed to the surface relatively recently — within the past 100,000 years or less.That makes Nightingale a very good site to find pristine organic material, which breaks down when exposed to sunlight."We do observe organics at the Nightingale site more so than some of the other candidate sites," Dr DellaGiustina said."It is also one of the reddest surfaces on Bennu, so we do think it's pretty fresh."That is exactly the sort of thing we want to gather a sample from." Researchers think Bennu could be made up of material from more than one source.This is because some of the boulders on the asteroid appear to contain a mineral called pyroxene (seen as green in the image above), which is found on a much larger asteroid called Vesta."I'm hoping there might be little fragments of material from Vesta in the sample," Dr DellaGiustina said.On October 21 (Australian time), the OSIRIS-REx spacecraft will attempt to land on the surface for 16 seconds and suck up about 60 grams of space dust off the surface.Heather Enos, OSIRIS-REx's deputy lead, said all the research leading up to the sample "proved" that Bennu was the right target for their mission."It really is going to give us the insight we are really looking for — the origins of the solar system," Ms Enos said.But collecting a sample won't be easy."Bennu has definitely given us several surprises in terms of what its characteristics are in terms of navigating to the surface and collecting a sample," she said.Not only has it proved rockier than predicted, it spins very fast and has small pebbles flying off the surface.If the spacecraft succeeds, we won't know what's in the dirt until it returns to Earth in 2023.Trevor Ireland, at the Australian National University, is part of the team that will analyse the sample.Professor Ireland said the discovery of carbonate veins on the asteroid was intriguing."We haven't actually seen anything like that in the meteorite collection," he said.Professor Ireland is also working with the Japanese mission which will return to Earth with a sample from another carbonaceous chondrite called Ryugu later this year."There may be some of that type of material on Ryugu too but maybe not as much, certainly we don't see those big long veins we're picking up on Bennu," he said.Professor Ireland said the finding of veins suggested the sample from Bennu may contain material that was originally deep within the parent asteroid rather than the surface."[The detection of carbonate] looks promising in terms of getting something a little bit different."Get all the latest science stories from across the ABC.Your information is being handled in accordance with the .8 Oct 20208 Oct 2020Thu 8 Oct 2020 at 6:15pm, 21 Oct 202021 Oct 2020Wed 21 Oct 2020 at 11:39pmMore on:

NASA gets ready to land on asteroid Bennu as new studies confirm it is a rich source of carbonShareIt may look like a grey space rock, but the asteroid known as Bennu is turning out to be far from boring.Later this month, a NASA spacecraft will land on this lumpy rock and suck up some dirt from its surface to bring back to Earth.The OSIRIS-REx probe has been circling the small asteroid between Earth and Mars preparing for this moment.When the spacecraft first sidled up to Bennu in 2018 it found the fast-spinning diamond-shaped rock was and there was evidence of on its surface. Now, six new...

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Genelle Weule is a senior science journalist, editor and digital producer at ABC Science. She has worked in the online space for more than 15 years at the ABC and has also contributed to ABC RN programs including Science Friction and The Science Show. She has also been nominated for and won several awards for digital projects she has produced. Before becoming a journalist she was an occupational therapist.

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Genelle Weule

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NASA gets ready to land on asteroid Bennu as new studies confirm it is a rich source of carbon - ABC News

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