The spacecraft Hayabusa-2 has sent back images of the crater that was made when it detonated an explosive charge next to the asteroid it is investigating.
On April 5, the Japanese probe launched a 14kg plastic explosive device against the asteroid Ryugu.
The explosion drove a copper projectile into the surface and hoped to create a 10 m wide depression.
Scientists want to get a "fresh" sample of rocks to better understand how the Earth and other planets formed.
Hayabusa-2 has now taken photos of the area where the Small Carry-On Impactor (SCI) process is about to detonate and identified a dark disorder in which fresh material was dug below the surface.
- Japanese spaceship "bombs" asteroid
Scientists from the Japanese Aerospace Agency (Jaxa) said the surface explosion area is about 20 meters in diameter – twice as large as the expected crater.
The mission's official report has tweeted: "We did not expect such a big change, so a lively debate was initiated in the project!"
Because of the debris that would have been thrown at this event, Hayabusa-2 maneuvered before the detonation on the 800 m wide side of the Ryugu – outside the danger area and out of sight.
The probe left a small camera called DCAM3 to watch the explosion.
Hayabusa-2 later returned to its "starting position" about 20 km above the surface of the asteroid. From here we searched for the crater created in the explosion.
In the coming weeks, scientists will order the probe to climb into the crater to collect their fresh samples.
Because they come from the asteroid, they are less affected by the harsh environment of the universe.
It is believed that bombardment with cosmic rays over the aeons alters the surfaces of these planetary building blocks.
Ryugu belongs to a particularly primitive space rock known as C-type asteroid. It is a remnant of the beginnings of our solar system and therefore captures the conditions and chemistry of that time – about 4.5 billion years ago.
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