The Japanese space agency (JAXA) denoted an explosive device on the surface of the Ryugu asteroid earlier this month. Now, Japanese scientists have confirmed that the blast created a crater with a diameter of 10 meters -- the first artificial crater on an asteroid.
"Creating an artificial crater with an impactor and observing it in detail afterwards is a world-first attempt," Yuichi Tsuda, Hayabusa2 project manager, said in a statement. "This is a big success."
The crater was created by the Hayabusa 2 spacecraft which fired an explosives-carrying projectile from 500 meters above the asteroid's surface. The goal was to discharge material from under the asteroid's surface in order to probe its chemical composition. The idea is that this fresh material could shed light on the formation of the early solar system. The asteroid is believed to be made up of organic compounds and water from 4.6 billion year ago.
Earlier this year, the probe fired a bullet into the surface of Ryugu in order to blast dust off the surface. But as the asteroid is constantly bombarded by solar rays which can alter its properties, samples need to be taken from beneath the surface -- hence the need for a crater-creating explosion. This time around, the Japanese mission made quite the mess, generating a ten-meter-wide crater. Initially, scientists predicted that the crater would be 3 meters in diameter if the surface is rocky and 10 meters in diameter if it is sandy.
"We can see such a big hole a lot more clearly than expected," said Masahiko Arakawa, a Kobe University professor involved in the project. "The surface is filled with boulders but yet we created a crater this big. This could mean there's a scientific mechanism we don't know or something special about Ryugu's materials."
The $270-million-mission is scheduled to return to Earth with samples taken from the asteroid in 2020. The samples will help scientists answer fundamental questions about the formation of the solar system. They might also inform the space mining industry with regard to the economic potential for similar asteroids