For six years, the Japan Aerospace Exploration Agency's Hayabusa2 spacecraft has been in space, on a mission to explore the near-Earth asteroid Ryugu.
The spacecraft was launched in 2014, and in 2018, it reached its target: the asteroid Ryugu (our earlier article here).
Now, Hayabusa2 is returning home, after accomplishing many space “firsts" including the release of a lander on an asteroid and the collection of surface and below-surface material for analysis!
The Mission to Meet Ryugu
The goal of the mission was to analyze the asteroid to learn more about the intricacies of space.
Asteroids are small, jagged rocks that orbit the Sun, like planets. Asteroid Ryugu is shaped like a top and is about 3,000 feet wide, with many large (but light) boulders.
The Japanese lander MASCOT took pictures of Ryugu, discovering that it was composed of equal amounts of dark, rough rocks and bright, smooth ones. This suggests that it was formed from the leftover rubble of a collision. The rocks were also very carbon-rich, similar to carbonaceous chondrites (a type of meteorite), and help explain Ryugu’s dark color.
The lack of a dust layer on Ryugu has puzzled scientists. They speculate that either solar radiation is charging and pulling dust particles away, or that collision with space objects or the movement of the asteroid is stripping dust from the surface.
A Scientific Explosion!
The Hayabusa2 also carried a Small Carry-on Impactor with explosives to blast a crater onto Ryugu to study how craters form.
The explosion created a 33-foot-wide, semi-circle shaped crater and sent up a plume of material. The material’s loose, sand-like properties suggest that the asteroid is only 9 million years old, a youngling in the space world. The plume also never fully left the surface, probably due to the asteroid’s gravitational pull.
A heat map of Ryugu shows that it absorbs and releases heat very quickly -- this indicates that the asteroid is porous with more than 50% holes. This is very different from meteorites found on Earth. It is possible that these porous and carbon-rich meteorites rarely crash into Earth and burn up in the atmosphere instead.
When Hayabusa2 finally returns to Earth, scientists can learn even more from the samples of Ryugu’s surface and interior, helping us uncover more about our mysterious galaxy.
Sources: Nature, New Scientist, Phys.org, CNN, Science News