On Thursday, Japan’s Hayabusa-2 probe successfully landed on asteroid Ryugu at 21:06 ET (01:06 UT) and sending us back some mind-blowing images.
In December 2014, Hayabusa-2 was launched into space by the Japan Aerospace Exploration Agency (JAXA). Its mission was to explore and collect samples from asteroid Ryugu, half-a-mile in diameter which orbits our sun at a distance up to 131 million miles (211 million kilometres).
In June 2018, the probe reached its target, then worked on observing, measuring the gravity of the asteroid, and rehearsing to touch down.
In April, it blasted the asteroid with a copper plate and a box of explosives to loosen rocks and expose material below the ground, then landed on Ryugu successfully last night to collect the rock and soil debris.
While leaving the asteroid Hayabusa-2 captured some stunning images which you can check below:
“The first image was taken at 10:06:32 JST (onboard time) and you can see the gravel flying up. The second shot was at 10:08:53 where the darker area near the centre is due to touchdown,” tweeted JAXA.
Primitive Rock Samples
Asteroids are made of rock and metal and take all sorts of quirky forms, from pebbles to 600-mile megaliths in size. Most of them hang out between Mars and Jupiter in the asteroid belt, although sometimes the orbit of Ryugu takes it between Mars and Earth.
Some asteroids date back to the dawn of our solar system 4.5 billion years ago when the remaining materials from planet formation coalesced into these rock pieces. Asteroids can serve as time capsules in that context: what researchers find in these primitive rocks might tell us a lot about the history of the solar system.
Ryugu is an asteroid of C-type, which implies it is rich with molecules of organic carbon, water, and potentially amino acids. Amino acids form the protein construction blocks and were vital for life on Earth to evolve. Some theories argue that an asteroid brought amino acids here for the first time, giving the seeds of life to our planet, although this is still under discussion.
Approximately three-quarters of the asteroids of our solar system are C-type. Hayabusa-2 is expected to be the first mission to bring samples from such an asteroid back to Earth.
Also Read: Hayabusa2 made a crater in Asteroid Ryugu
The probe first landed on Ryugu in February and gathered shallow samples just below the surface. But mission engineers decided to collect some deeper rock samples since these materials were not exposed to severe space weathering. The probe had to lift back from the asteroid, then shoot a 10-meter crater into the surface to get to the rock below.
In April, Hayabusa-2 released a box of explosives that shot a copper plate into the asteroid and detonated it. And then on Wednesday, the landing made a splash in all that freed-up material.
“These pictures were taken by the small monitor camera (CAM-H) before and after touchdown. The first is 4 seconds before touchdown, the second is at touchdown itself and the third is 4 seconds after touchdown. In the third picture you can see the amount of rocks that rise,” tweeted JAXA.
Hayabusa-2 then gathered a fresh set of samples after it touched down and left the surface of Ryugu. It will begin the 5.5 million-mile (9 million-kilometre) voyage back at the end of this year. So far, it’s all on schedule.
Similar mission planned by NASA
A faraway asteroid is also being studied by NASA. In August 2018, the OSIRIS-REx mission of the agency reaches a much smaller C-type asteroid, Bennu. But the probe did not land on the surface of Bennu. Instead, it was orbiting at a record-breaking close range.
The plan is for OSIRIS-REx to approach the surface of Bennu in July 2020, but the spacecraft will only make contact for about five seconds. It will blow up nitrogen gas during that fast moment to stir up dust and pebbles and retrieve the samples. If everything goes according to plan, this material will be returned to Earth in 2023.
However, the surface of the asteroid has turned out to be rougher than anticipated, and debris that flies off the space rock may pose a danger to the spacecraft in orbit. Therefore, NASA still choosing its sampling site.
But Bennu has already made a significant finding. In December, the probe found that the asteroid harboured water components (oxygen and hydrogen atoms bonded together) before it went into orbit around Bennu.
Also Read: Asteroid Bennu Keeps Spinning Faster
Bennu is too small to host liquid water, but water may once have existed on its parent asteroid, which Bennu broke away from between 700 million and 2 billion years ago.
While NASA’s asteroid exploration mission will collect a bigger amount of sample material than Japan’s, the JAXA team hopes that comparing samples from two different locations on the same asteroid will provide new information on how long-term space exposure changes asteroids over time.
Both Bennu and Ryugu could also teach scientists a lot about the solar system’s history and possibly about the origins of life on Earth if they contain organic materials.