The Yomiuri ShimbunThe Hayabusa2 space probe on Thursday successfully completed a second landing on the asteroid Ryugu after its first landing in February, the Japan Aerospace Exploration Agency (JAXA) said.
The unmanned probe touched down on an area near a crater it had created previously on the asteroid, JAXA said, and the mission this time was to collect material from subsurface rocks that were exposed when the crater was formed. If successful, the world may obtain important clues to the evolution of the solar system.
Hayabusa2 is engaged in the world’s first attempt to create an artificial crater on an asteroid and collect samples from its subsurface rocks. It is believed that the subsurface materials of the asteroid are less weathered by cosmic radiation than rocks on the surface.
In April, a device called an impactor detached from the explorer and fired a copper plate weighing about 2 kilograms into the surface of Ryugu, successfully creating the crater, which is about 10 meters in diameter. Subsurface materials that were thrown out by the impact are believed to have piled up around the crater to a height of about 1 centimeter.
Ryugu is currently about 240 million kilometers from Earth. On Wednesday, Hayabusa2 began descending from a point about 20 kilometers away from the asteroid. On Thursday, the explorer shifted to autonomous operation when it reached an altitude of less than 500 meters. It came close to the crater while identifying a target marker that had been dropped on the surface in advance. Hayabusa2 then successfully touched down on Ryugu after 10 a.m. Japan time on Thursday. At about the same time, it fired a bullet to stir up the material in order to collect samples of it, before swiftly ascending.
The samples collected this time will be kept in a container aboard the spacecraft, but in a separate chamber from where samples collected previously are already kept, in order to avoid mixing.
Asteroids are small bodies that gradually formed when bits of cosmic dust repeatedly coalesced, and their makeup is believed to reflect conditions from the time the solar system was formed 4.6 billion years ago. The sand and rocks of Ryugu, in particular, are expected to contain organic substances that are essential for life. There is great anticipation that the material sampled from Ryugu will be key to learning more about the evolution of the solar system and the origin of life.
Hayabusa2 arrived at Ryugu in June 2018. The explorer will drop a small robot probe, developed by a joint team of five universities, on the surface of Ryugu sometime in this summer, and Hayabusa2 will leave Ryugu’s orbit sometime in November or December for its return journey to Earth, arriving at the end of 2020 to deliver the samples it holds.Speech