In 2016, the OSIRIS-REx space probe was launched. In 2018, it reached its destination, asteroid Bennu. It’s a potato-shaped space rock that orbits the sun.
Although the name of the space rock suggests otherwise, Bennu is not a massive entity, says Daphne Stam. “It’s a bunch of pebbles held together by a little bit of gravity, kind of a cloud of rocks together.”
333 million kilometers
Bennu was measured for the first time and imaged from all angles by the space probe. That data was then sent back to Earth for study.
In October 2020, OSIRIS-REx absorbed approximately 250 grams of rocks and dust. It happened approximately 333 million kilometers from Earth. The asteroid samples were collected in a container on board the probe.
The OSIRIS-REx probe remains in space and launched a capsule containing the collected debris container about 100,000 kilometers from Earth. That capsule flew into the atmosphere four hours later at a speed of approximately 45,000 kilometers per hour.
The capsule’s landing this afternoon, in the desert of the American state of Utah, was broadcast live on the US space agency NASA’s website and can be viewed here:
Bennu is composed of primordial material dating back to the time when our solar system was formed. So the debris now brought to Earth could teach us more about the origins of this solar system 4.5 billion years ago. “What’s interesting is the search for the basic elements of life,” Stamm explains.
the origin of life
The planetary scientist explains that we are all made of molecules that contain a lot of carbon. “These are called organic molecules. It is very interesting to know if the same building blocks are also present in this asteroid. Because we do not know where life comes from on Earth.”
It could be dangerous for us
Bennu can thus provide answers to questions about the origins of life. But at the same time it threatens that life a little bit. There is a chance – albeit a very small one – that it will collide with Earth in 2135. “It’s about a 1 in 2,000 chance. But it’s very close. So it’s probably going to be a dangerous asteroid.”
Stam describes that it is not very large, measuring 500 meters in diameter. “But if it collides with a city here on Earth, that city will disappear.” All the more reason to study Bennu carefully.
unique?
This is the first time that Americans have recovered material from an asteroid. Japan preceded them with the Hayabusa and Hayabusa 2 missions, but returned smaller payloads.
According to Daphne Stam, scientists were unable to measure how many grams of gravel were collected. It is already clear that more material has been brought in than ever before.
