Asteroid Ryugu contains material older than the planets,

Amazing mission.
The black stuff reminds me of what Arthur Clarke wrote
about in his book "2061: Odyssey Three" when Heywood Floyd
get to land on Halley's Comet.
https://en.wikipedia.org/wiki/2061:_Odyssey_Three

from
https://www.space.com/asteroid-ryugu-sample-older-than-planets

Asteroid Ryugu contains material older than the planets, among the most 
primitive ever studied on Earth
By Keith Cooper published 1 day ago

Samples returned to Earth by a Japanese asteroid mission are the most 
untouched materials ever studied in the solar system.

An artist's depiction of the Hayabusa2 spacecraft at the asteroid Ryugu. 
(Image credit: NASA)

The asteroid Ryugu contains some of the most primitive material ever 
studied in a laboratory on Earth, dating back to just 5 million years 
after the formation of the solar system, according to an analysis of 
samples retrieved by Japan's Hayabusa2 mission.

Because it is so old, it is made of the same stuff that formed the 
planets. "Ryugu is one of the building blocks of Earth," team-member 
Hisayoshi Yurimoto, a professor at Hokkaido University in Japan, told 
Space.com.

The Japan Aerospace Exploration Agency's Hayabusa2 spacecraft launched 
in December 2014 and arrived at asteroid Ryugu in 2019. It retrieved two 
small samples of regolith, amounting to 5.4 grams, from the asteroid. 
These samples then landed on Earth in a capsule equipped with a 
parachute in December 2020.

Related: Japan's Hayabusa2 asteroid Ryugu sample-return mission in pictures

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Upon their return, the samples were distributed among scientific groups, 
including one team led by Tetsuya Yokoyama, a professor at the Tokyo 
Institute of Technology. The team's newly published results suggest that 
the composition of the samples is the closest match to the solar nebula 
— the gas cloud that condensed to form the sun and planets — ever found. 
As such, it is made up of the ingredients that formed the solar system 
4.5 billion years ago.

The findings support previous research that also concluded that Ryugu 
was made of primitive material, but until now it wasn’t known just how 
old it was.

Ryugu is a carbonaceous chondrite, meaning it is made from carbon-rich 
stony material. But remote observations by Hayabusa2 found some 
unexplained discrepancies ​​— including a darker surface color, a larger 
abundance of phyllosilicate materials and a more porous composition than 
expected — so laboratory analysis was required to better understand the 
asteroid's true nature. Ryugu is somewhat similar to the Ivuna 
meteorite, which fell in Tanzania in 1938 and was loaned by the Natural 
History Museum in London to Yokoyama's team for their study.

"The comparison between Ivuna and Ryugu is very helpful for revealing 
the characteristics of Ryugu," Yurimoto said.

Utilizing a range of techniques — including electron microscopy, X-ray 
fluorescence, inductively coupled plasma mass spectrometry and thermal 
ionization — the team found that the samples had formed within liquid 
water, at a temperature of about 81 to 117 degrees Fahrenheit (27 to 47 
degrees Celsius), roughly 5 million years after the solar system began 
to form.

JAXA personnel inspect Hayabusa2's return capsule against the red soil 
of the Woomera Prohibited Area in Australia on Dec. 5.

With a diameter of just 3,000 feet (900 meters), Ryugu is too small to 
have generated enough heat to melt water ice. Therefore, Ryugu itself 
must have originated from a larger parent body that formed just 2 
million to 4 million years after the birth of the solar system. At some 
point after 5 million years, a powerful impact with another asteroid 
smashed Ryugu's parent body apart, with some of the fragments forming 
Ryugu. This idea is supported by the presence of large boulders on 
Ryugu's surface, which appear to have originated as debris from a giant 
impact.

Ryugu's material can be dated thanks to the abundance of certain 
elements — hydrogen and noble gases — within the samples. They are the 
closest match that we have for the composition of the sun's visible 
surface, the photosphere, which is used as a proxy for the composition 
of the solar nebula.

No meteoritic or asteroidal material studied in a laboratory on Earth 
has ever been found to be so primitive and pristine. Some meteorites, 
like Ivuna, may have once been as pristine. But after lying on Earth for 
decades, if not centuries — where they were exposed to atmospheric 
moisture and weathering, and then handled by humans — their mineralogies 
and elemental composition may have been compromised.

One key question that needs to be answered to fully explain the origin 
of the planets is where minor bodies, such as asteroids and comets, some 
of which became planetary building blocks, formed. Their compositions 
suggest that many of these bodies did not form in their current orbits 
and that in the chaotic early solar system, with its turbulent 
protoplanetary disk and migrating planets, the minor bodies were pushed 
around and moved away from where they formed.


By knowing when Ryugu's parent body formed, and that it contained water, 
can we say where the asteroid must have formed?

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"This is a very difficult question," Yurimoto said. "We have no 
quantitative answer, but it would be beyond the snow line of the solar 
system, [which is] located at the orbit of Jupiter." (The snow line is 
the distance from the sun where water ice could have condensed during 
the formation of the solar system.)

This is only the beginning of the analysis of the samples brought home 
by Hayabusa2. The next step is to use the information contained within 
those samples to determine the abundances of various elements and their 
isotopes in the early solar system when the planets were forming. 
According to Yurimoto, once determined, those abundances "would become a 
new standard for studies of the solar system."

The findings are published in the June 9 issue of the journal Science.

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