2018年4月8日外汇牌价Watch Japans Hayabusa spacecraft shoot a bullet at an asteroid ThursdayWatch Japans Hayabusa spacecraft shoot a bullet at an asteroid Thursday Lets fire a bullet at an asteroid. This might sound like a plot point from a sci-fi show, but its about to become reality when Japans space agency JAXA directs its Hayabusa 2 spacecraft to go grab a sample of an asteroid.Hayabusa 2 arrived at the asteroid Ryugu in mid-2020 and has already delivered two rovers and a lander to the surface. But touching down on the rock with its sampler horn is a sensitive operation.JAXA delayed the touchdown from last fall after discovering Ryugus surface was much rockier than expected. The new sample collection time is set for Friday, Feb. 22 at 8 a.m. Japan time, which works out to Thursday, Feb. 21 at 3 p.m. Pacific in the US.JAXA will broadcast live online from its control room with an English translation available.The spacecrafts cylindrical sampler horn is designed to touch the asteroids surface, fire a bullet into the rock and then gather up the fragments ejected by the impact.The Hayabusa 2 team conducted an experiment on Earth to see if the sampler is likely to work with Ryugus gravelly surface. The test involved firing a projectile into a simulated surface made to mimic the asteroid. According to the results, the spacecrafts system should work just fine.The touchdown is still a daring operation. The spacecraft will have to avoid boulders, but still get close enough to reach the surface. If all goes well, Hayabusa 2 will return to Earth in late 2020 with a bit of asteroid on board for scientists to study.