The best gift of this holiday season came in a small package, parachuted into the Australian desert from far away from our solar system, on December 5, 2020.
Inside, astronomers were delighted to unravel the first significant samples of a rocky asteroid currently located 9 million kilometers (5.6 million miles) and returned to Earth in “perfect” shape.
Photographs of the virgin pebbles have finally been published, and although the small black grains inside look nothing more than raw coal, this galactic gift is no suppressed. It is the culmination of a five-year journey that requires careful planning and execution.
The samples were originally collected by the Japanese mission Hayabusa2, which was sent in a circle and shows the diamond-shaped asteroid called Ryugu, after the success of its first mission.
Samples of the asteroid Ryugu in the re-entry capsule weigh about 5.4 g. This far exceeds the target yield of 0.1 g (the amount required for initial scientific analysis) established during the design of Hayabusa2.
(Article in Japanese: https://t.co/IZFGinhuFc)– HAYABUSA2 @ JAXA (@ haya2e_jaxa) December 18, 2020
The initial Hayabusa spacecraft returned from the asteroid Itokawa in 2010 with the first direct sample of an object close to Earth. In total, the surface material weighed less than a milligram, and yet it was sufficient to give crucial information about the age and geological history of the asteroid.
Ryugu’s new samples, collected last year, go back even further and contain more material than astronomers dared to expect, amounting to approximately 5.4 grams.
Ryugu’s name refers to a magical underwater “dragon palace” of Japanese folklore, in which a fisherman is presented with a mysterious box to return home, rather like Hayabusa’s sealed capsules.
In this case, the treasure is believed to be over 4.5 billion years old, a relic of our primitive solar system, which contained potentially ancient material that formed the Sun and its orbiting planets.
By opening the carefully sealed chambers, astronomers have found many particles larger than a millimeter. Those in Chamber C were slightly larger than the rest and were picked up from the second touchdown of the mission.
Sample capture chamber A, captured with an optical microscope. (JAXA)
Because this landing occurred a little north of a crater intentionally created before the mission, the researchers expected the sample to contain pieces of underground material. This would be quite a success, as all the other asteroid samples collected in space only come from the surface.
Prior to these direct samples, most of our knowledge on the subject of asteroids came from meteorites, which are asteroids or comets that are found crushing on the Earth’s surface.
Unfortunately, without the protection of a human-made capsule, much of this material is destroyed or contaminated by the atmosphere of our planet at the entrance, not to mention all the weathering that occurs once these rocks rest on the ground. .
Ryugu is a type C asteroid which means that its rock is very porous and contains a lot of carbon and water. Astronomers suspect that this particular pile of dark debris formed billions of years ago, when it broke another large body of rock somewhere in the asteroid belt between Mars and Jupiter.
Because Ryugu’s surface appears unusually dry and has a red coloration, some experts think it once flew closer to the Sun.
However, not all the material collected in these containers is so essential. One of the capsules contains an obvious anachronism (pictured below).
Sample capture chamber C, captured with an optical microscope. (JAZA)
“It appears the artificial material is present in chamber C,” says a press release from the Hayabusa2 project.
“The origin is being investigated, but a likely source is that the aluminum was ripped from the spacecraft’s sampling tube while the projectile was fired to remove material during contact.”
Later one update of Twitter said the object was not yet confirmed, but that it could have been separated from the sampling horn used during the collection.
The conservation work of the Ryugu sample is constantly advancing. On December 21, the B&C sample capture chambers were opened and then the contents of the A&C chambers were moved to the photo collection containers. The largest particles in chamber C are about 1 cm long! pic.twitter.com/yWO15cKhG9
– HAYABUSA2 @ JAXA (@ haya2e_jaxa) December 24, 2020
Scientists are already beginning to analyze these new samples, including some gas trapped inside the capsules, which is believed to have also been collected on the surface of Ryugu.
If the researchers are right, it will be the world’s first gas sample returned from deep space.
All the present, in fact.