Japanese spacecraft arrives at asteroid to probe its insides
Image credit: pa
The Japan Aerospace Exploration Agency (JAXA) has confirmed that a probe (pictured) launched three-and-a-half-years ago has arrived at its intended destination near an asteroid that is orbiting the Sun.
The asteroid, named Ryugu after an undersea palace in a Japanese folktale, is about 900m in diameter and orbits the Sun about once every 16 months.
Asteroids, which orbit the Sun but are much smaller than planets, are among the oldest objects in the solar system.
As such, they may help explain how Earth evolved, including the formation of oceans and the start of life.
The Hayabusa 2 probe blasted off in December 2014 and is expected to return in 2020 with samples of the asteroid.
The unmanned spacecraft reached its base of operations about 12 miles from the asteroid and some 170 million miles from Earth.
“Everything has gone as planned,” a spokesman for the Japan Aerospace Exploration Agency (JAXA) told a news conference. “The probe has arrived at the asteroid”.
Over the next year and a half, the spacecraft will attempt three brief touch-and-go landings to collect samples.
If the retrieval and the return journey are successful, the asteroid material could provide clues to the origin of the solar system and life on Earth.
The robotic explorer will spend about two months looking for suitable landing places on the uneven surface. Due to the high surface temperature, it will stay for only a few seconds each time it lands.
In photos released by JAXA the asteroid appears more cube-shaped than round and a number of large craters can be seen, which Project Manager Yuichi Tsuda said in an online post makes the selection of landing points “both interesting and difficult.”
The first touchdown is planned for September or October.
Before the final touchdown scheduled for April-May, Hayabusa2 will send out a squat cylinder that will detonate above the asteroid, shooting a 2kg copper projectile into it at high speed to make a crater.
Hayabusa2 will hide on the other side of the asteroid (pictured below) to protect itself during the operation and wait another two to three weeks to make sure any debris that could damage the explorer has cleared.
It will then attempt to land at or near the crater to collect underground material that was blown out of the crater, in addition to the surface material from the earlier touchdowns.
The spacecraft will also deploy three rovers that do not have wheels but can hop around on the surface of the asteroid to conduct probes.
Hayabusa2 will also send a French-German-made lander to study the surface with four observation devices.
An earlier Hayabusa mission from 2003 to 2010 collected samples from a different type of asteroid and took three years longer than planned after a series of technical glitches, including a fuel leak and a loss of contact for seven weeks.