JAXA releases video of Hayabusa2 touching down on asteroid Ryugu
TOKYO -- The Japan Aerospace Exploration Agency (JAXA) released a video on March 5 showing its space probe Hayabusa2 touching down on the asteroid Ryugu.
The images were taken by a camera on the spacecraft that was created using donations of about 12 million yen from the general public. They show pieces of rocks and stones on the asteroid's surface being raised like confetti when a tubular device to collect materials touched down and bounced up.
Project manager Yuichi Tsuda said at a press conference in Tokyo, "They are really fantastic images. I felt a thrill when I saw them for the first time." He added, "Through the donations we were able to take such images. Thank you."
(Japanese original by Tomohiro Ikeda, Science & Environment News Department, and Etsuko Nagayama, Opinion Group)
Quelle: The Mainichi
Hayabusa2 landed on the asteroid on Feb. 22 and JAXA officials say the probe has likely collected rock samples.
The probe is scheduled to detach a device loaded with explosives some 500 meters away from Ryugu. The device will set off the explosives using a timer some 40 minutes later and launch a copper "impactor" weighing about 2 kilograms into the asteroid's surface.
The target point is several hundreds of meters away from where the space probe first touched down. The mission will require the spacecraft to move quickly to the other side of the asteroid so it won't get hit by flying shards from the blast. A detached camera will shoot the moment of impact.
JAXA will analyze the size and shape of the crater, and how rocks fly off in a bid to collect underground samples for possible clues to the origin of the solar system.
Koji Wada, chief researcher of the Chiba Institute of Technology who is in charge of the analysis of the experiment, said, "I want to reveal the origin of heavenly bodies which repeatedly collided and broke up. I'm excited that we will be able to conduct this experiment on a real asteroid."
Quelle: The Mainichi
Ryugu latest: asteroid is a partially dehydrated ‘pile of rubble’
Japanese researchers publish three studies on the object of Hayabusa2’s attention. Richard A Lovett reports.
A one-kilometre-wide asteroid known as 162173 Ryugu, currently being mapped by Japan’s Hayabusa2 spacecraft, looks like a giant “pile of rubble” shaped like a spinning top, planetary scientists report in a trio of papers in the journal Science.
The asteroid also has extremely low density, indicating that it is riddled with porous gaps, much like a chunk of Styrofoam or Swiss cheese.
To determine the asteroid’s shape, the scientists used photographs from multiple angles, and laser range-finding mapping of its topography to create a 3D model.
Its porosity was calculated by watching as the spacecraft fell to within 850 metres of the surface, then rose to 5.4 kilometres. Based on this, says Sei-ichiro Watanabe, of Nagoya University, Japan, it was possible to determine the asteroid’s mass, volume, and average density.
The third of these are so low that gaps of various sizes must make up half of the asteroid’s volume, he says – assuming it is made of the same type of minerals as a class of meteorites known as carbonaceous chondrites.
The spinning top shape, he adds, is probably a leftover from its youth, when rapid rotation deformed it into a flattened shape with a prominent equatorial ridge that still persists, even though its rotation has now slowed to a sedate 7.6 hours.
Why this ridge has not slowly flattened out, Watanabe says, is an open question, but he thinks it’s because the surface materials on Ryugu must not easily avalanche.
“It seems the friction angle of materials on Ryugu is large enough, so the relaxation process would be rather slow,” he says.
In another study, a team led by Seiji Sugita, of the University of Tokyo, Japan, used data from the spacecraft’s near-infrared spectrometer to find that water-containing minerals are “ubiquitous” across Ryugu’s surface.
That said, these materials appear to have been “thermally metamorphosed” and partially dehydrated.
Most likely, Sugita says, Ryugu stems from a parent body that was formed about 4.56 billion years ago, at the birth of the Solar System.