Japan asteroid probe in 'tantalizing' solar system discoveries

Ryugu is a carbon-rich C-type asteroid about 900m wide.

(CNN)An unmanned Japanese spacecraft orbiting an asteroid has made surprising discoveries that scientists say will improve understanding about the origin's of the Earth's water and help search for life in other solar systems.

Scientists working on Japan's Hayabusa 2 space mission said that by using a wide range of cameras and instruments to collect images and data about the near-Earth asteroid Ryugu, they had made some "tantalizing discoveries."
"The primary one being the amount of water, or lack of it, Ryugu seems to possess," said Seiji Sugita of the University of Tokyo's Department of Earth and Planetary Science in a press statement as the mission released its initial findings.
    "It's far dryer than we expected, and given Ryugu is quite young (by asteroid standards) at around 100 million years old, this suggests its parent body was much largely devoid of water too," Sugita added.
      The finding is significant, he said, because of all of Earth's water is thought to have come came from local asteroids, distant comets and the nebula or dust cloud that became our sun.
      "The presence of dry asteroids in the asteroid belt would change models used to describe the chemical composition of the early solar system," he added.
      The discovery also has implication for finding extraterrestrial life. "There are uncountably many solar systems out there and the search for life beyond ours needs direction," Sugita said. "Our findings can refine models that could help limit which kinds of solar systems the search for life should target."
        The mission's three initial papers published in the journal Science on Tuesday described the mass, size, shape, density, spin and geological properties of the asteroid, a porous "pile of rubble" shaped like a spinning top.
        Ryugu is extremely dark and looks blacker than coal to our eyes.
        The Japanese space agency, JAXA, research has also benefited from cooperation with NASA, which has its own probe, OSIRIS-REx, exploring a different asteroid known as Bennu.
        NASA and JAXA share data from their respective missions and this cooperation has thrown up a further surprise.
        Both Bennu and Ryugu are extremely dark, spinning-top shaped asteroids that are covered in large boulders, but the latest findings show that Ryugu is a lot drier.
        Researchers had expected the two asteroids to have similar levels of water, but the discrepancy has opened up new avenues for future research.
        "Thanks to the parallel missions of Hayabusa2 and OSIRIS-REx, we can finally address the question of how these two asteroids came to be," Sugita said. "That Bennu and Ryugu may be siblings yet exhibit some strikingly different traits implies there must be many exciting and mysterious astronomical processes we have yet to explore."
        Other scientists shared Sugita's optimism. "It seems that the asteroid formed as a spinning rubble pile from a previous generation of asteroidal parent bodies, and that those parent bodies had undergone thermal or shock metamorphism," said John Bridges from the space research center at UK's University of Leicester.