The Japanese Hayabusa2 spacecraft on December 6 dropped a capsule from about 200 kilometers above the earth’s surface to the ground in the Australian outback. This capsule contains one of the most valuable cargos in the solar system: the dust that the spacecraft collected from the surface of asteroid Ryugu earlier this year.
By the end of 2021, the Japan Aerospace Exploration Agency (JAXA) will distribute samples of Ryugu to six teams of scientists around the world. These researchers will prod, heat, and examine these ancient grains to learn more about their origins.
Ryugu’s research teams include scientists from the Astrobiology Analysis Laboratory at NASA’s Goddard Space Flight Center in Greenbelt, Maryland. Researchers in the astrobiology lab use advanced tools similar to those found in forensic laboratories to solve crimes. Instead of solving crimes, NASA’s Goddard scientists examine space rocks for molecular evidence that can help them piece together the history of the early solar system.
“What we’re trying to do is better understand how Earth evolved into what it is today,” said Jason P. Dworkin, director of the Goddard’s Astrobiology Analytical Laboratory. “How, from a disk of gas and dust that coalesced around our forming Sun, did we get to life on Earth and possibly elsewhere?”
Dworkin is the international deputy of a global team that will examine a sample of Ryugu to search organic compounds that are precursors to life on earth.
Ryugu is an ancient fragment of a larger asteroid that formed in the cloud of gas and dust from which our solar system emerged. It is a fascinating type of carbon-rich asteroid, a vital element.
When Dworkin and his team will get their share of a Ryugu sample next summer, they will search organic or carbon-based compounds to better understand how these compounds were formed and spread throughout the solar system.
Organic compounds of interest to astrobiologists include amino acids, molecules that make up hundreds of thousands of proteins that are responsible for some of the most important functions in life, such as the production of new DNA. By studying the differences in the types and amounts of amino acids stored in space rocks, scientists can create a record of how these molecules were formed.
Ryugu’s dust, currently 9 million miles or 15 million kilometers from Earth, will be one of the pristine space materials that scientists have found. This is the only second sample of an asteroid that has been collected from space and returned to Earth.
Before the Ryugu expedition, JAXA returned small samples of the Itokawa asteroid in 2010 as part of the first asteroid sampling mission in history. NASA previously obtained a small sample from Comet Wild-2 as part of its Stardust mission in 2006. And then, in 2023, NASA’s OSIRIS-REx will return at least a dozen ounces or hundreds of grams of asteroid Bennu, which has been travelling through space for billions of years and has hardly changed.
“Our final objective is to understand how organic compounds formed in the extraterrestrial environment,” said Hiroshi Naraoka, professor of geochemistry at Kyushu University in Fukuoka,
Japan, and the lead of the global Hayabusa2 team that will analyze Ryugu’s organic composition. “So we want to analyze many organic compounds, including amino acids, sulfur compounds, and nitrogen compounds, to build a story of the types of organic synthesis that happens in asteroids.”
After analyzing Ryugu’s structure, scientists can compare it to Bennu, the location where OSIRIS-REx conducted an extremely successful survey, which briefly landed on the asteroid’s surface on October 20.
“The two asteroids have similar shapes, but Bennu appears to have a lot more evidence of past water and of organic compounds,” said Dworkin, whose lab also is due to receive a tenth of an ounce, or several grams, of Bennu. “It’ll be very interesting to see how they compare, given they came from different parent bodies in the asteroid belt and have different histories.”