Japan’s Hayabusa 2 probe has been staking out the asteroid Ryugu for several months now, and the time has almost arrived for the spacecraft to start taking shots at the surface. In a few hours, Hayabusa 2 will launch a small projectile at Ryugu to dislodge material from the surface, which it will then attempt to scoop up.
The Japan Aerospace Exploration Agency (JAXA) originally wanted to start up its outer space shooting gallery last year, but the conditions on Ryugu were a surprise. Upon reaching the asteroid, Hayabusa 2 deployed two small drum-like robots (MINERVA-II1A and MINERVA-II1B) to bounce around the surface. Images relayed by the landers showed that Ryugu wasn’t covered with a fine layer of dust as expected. Instead, the surface is strewn with craggy rocks that will require a precision landing.
After scouting a location, JAXA is ready to move Hayabusa 2 in for a landing. It will fire the probe’s thrusters at about 6 PM EST (8 AM on Feb. 22 for Japan). The team already deployed a small target marker on the surface to help guide Hayabusa 2 in for a landing. After coming in contact with the surface, the spacecraft will launch its titanium slug and try to scoop up material from the ejecta with its sample container. The tweet below has a YouTube stream of the event.
Later this spring, Hayabusa 2 will stop going easy on Ryugu. After moving to a safe distance, the probe will launch a small explosive projectile. The hope is the detonation will create a small crater and expose subsurface material that hasn’t been bombarded by solar radiation for billions of years. Hayabusa 2 carries a second impactor like the first, which JAXA can use to excavate some material from the crater.
(with English translation.)
You can also ask us questions with the hashtag #haya2_QA (though we apologise if we cannot answer them all).
— HAYABUSA2@JAXA (@haya2e_jaxa) February 21, 2019
JAXA hopes to collect about 100 milligrams of material from Ryugu and then send it back to Earth for analysis. Even if the collection goes off without a hitch, the sample return container won’t be back on Earth until late 2020.
Ryugu is one of a class of objects called c-type asteroids. They’re ancient, and most likely composed of the same material that coalesced into the sun and planets billions of years ago. In addition to the bulky carbon-containing compounds, these asteroids may also have trace amounts of water from the early solar system. Getting the samples back to Earth could help scientists learn about the earliest history of our solar system.