The best gift of this holiday season comes in a small package, which is parachuted into the Australian desert from far within our solar system on 5 December 2020.
Inside, astronomers were delighted with the first major samples of a rocky asteroid currently 9 million kilometers away, returning to Earth in ‘perfect’ form.
Eventually, photos of the pristine pebbles were released, and although the small, black-colored grains inside may look nothing more than dirty coal, this gift is hardly a gift. It is the culmination of a five-year journey that requires careful planning and execution.
The monsters were originally collected by the Japanese Hayabusa2 mission, which was sent after the success of its first mission to circle and sample the diamond-shaped asteroid named Ryugu.
The samples of the asteroid Ryugu in the re-import capsule weigh about 5.4 g! This exceeds the target yield of 0,1 g (the quantity required for the initial scientific analysis) determined during the design of Hayabusa2.
(Article in Japanese: https://t.co/IZFGinhuFc)– HAYABUSA2 @ JAXA (@ haya2e_jaxa) 18 December 2020
The initial Hayabusa spacecraft returned from the asteroid Itokawa in 2010 with the first direct sample of a near-Earth object. In total, the surface material weighed less than a milligram, and yet it was still enough to provide important information about the age and geological history of the asteroid.
The new samples from Ryugu, which were recorded last year, date even further and contain more material than astronomers ventured into, weighing about 5.4 grams.
The name Ryugu refers to a magical ‘dragon palace’ in Japanese folklore, in which a fisherman is given a mysterious box to return home with – rather like Hayabusa’s sealed capsules.
The treasure is believed to be more than 4.5 billion years old – a remnant of our early solar system that contains potentially ancient material that once formed our sun and its orbiting planets.
By opening the carefully sealed chambers, astronomers found many particles larger than a millimeter. Those in Room C were slightly larger than the rest and were picked up from the mission for the second time.
Sample capture chamber A, captured by an optical microscope. (JAXA)
Because this landing took place a little north of a crater that was deliberately created earlier in the mission, researchers expected the sample to contain pieces of underground material. This would be a great achievement, because all other asteroid samples collected in space simply come from the surface.
Before these direct monsters, most of our knowledge about asteroids comes from meteorites, that is, asteroids or comets that break on the earth’s surface.
Unfortunately, without the protection of a man-made capsule, much of the material is destroyed or polluted by the atmosphere of our planet upon entry, not to mention all the weathering that occurs once these rocks land on the ground.
Ryugu is a 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 off another large rock in the asteroid belt between Mars and Jupiter.
Because Ryugu’s surface looks extremely dry and displays red colors, some experts think it once flew closer to the sun.
Yet not all of the materials collected in these containers are as original. One of the capsules contains a clear anachronism (shown below).
Sample capture chamber C, captured by an optical microscope. (JAZA)
‘Artificial material appears to be in room C’, reads a press release from the Hayabusa2 project.
“The origin is being investigated, but a probable source is aluminum that was scraped off the spacecraft sampler while the projectile was fired to generate material during contact.”
Later a update of Twitter said the object had not yet been confirmed, but that it may have separated from the sampler used during the collection.
The curatorial work for the Ryugu monster is progressing steadily. On December 21st, sample collection rooms B&C were opened and then the contents of rooms A&C were moved to the collection containers in the photo. The largest particles in room C are about 1 cm! pic.twitter.com/yWO15cKhG9
– HAYABUSA2 @ JAXA (@ haya2e_jaxa) 24 December 2020
Scientists are already analyzing these new samples, including gas trapped in the capsules, which were presumably also collected on the surface of Ryugu.
If researchers are correct, it will be the first gas sample in the world to be retrieved from deep space.
Indeed the current.