TOKYO – Japanese space experts said Thursday they will examine soil samples brought back from a distant asteroid in an attempt to find the heat source that altered the celestial body in their search for clues to the origins of the solar system and life on Earth.
Scientists at the Japan Aerospace Exploration Agency said they conducted a preliminary study of 5.4 grams (0.19 ounces), far more than the minimum 0.1 gram sample they had hoped for the Hayabusa2 spacecraft in December. brought back from the asteroid Ryugu, more than 190 million miles from Earth.
About 3 grams of the black grains come from the surface of Ryugu and were collected when Hayabusa2 hit the asteroid in April 2019. About 2 grams of larger fragments, up to about 0.4 inch, were obtained from below the surface in a crater created by Hayabusa2 when it landed a second time three months later.
Based on near-infrared spectrophotometer analysis of data sent by Hayabusa2, JAXA scientists found that the asteroid was exposed to extremely high temperatures, both on the surface and underground, possibly caused by an internal heat source or planetary collisions rather than heat from the sun.
Kohei Kitazato, a planetary scientist from the University of Aizu who works with JAXA, said his team had found evidence of heat in excess of 572 degrees Fahrenheit both on the asteroid’s surface and underground.
He said the subterranean soil would not reach that temperature due to the heat of the sun alone, suggesting that radiant heat or planetary collisions affected Ryugu when billions of years ago was part of a parent body, causing the water to evaporate.
His previous research, conducted with scientists from Brown University and more than 30 other institutions, was published last month in the journal Nature Astronomy.
JAXA continues the initial examination of the asteroid samples, pending more complete studies next year. Scientists will also investigate possible traces of organic matter in the hope that they will provide insight into the origins of the solar system and life on Earth.
After studies in Japan, some samples will be shared with NASA and other international space agencies for additional research.
Hayabusa2 continues an 11-year expedition to another small and distant asteroid, 1998KY26, to study possible defenses against meteorites that could fly to Earth, while conducting various tests that could be used in future Japanese space missions, including the planned 2024 MMX monster return mission from one of Mars’ moons.