After tracking the beinu asteroid for a year, NASA finally determined the sampling location.Taking on NASA's first asteroid sampling and return mission, Osiris Rex launched in September 2016. It took nearly two years to get close to beinu after a long journey. Since then, it has been around the asteroid for observation and sampling.
On December 12, NASA announced a site called "Nightingale". If all goes well, Osiris Rex will spray a stream of nitrogen to blow away the dust on the surface and extend a mechanical arm to collect samples.
Osiris Rex probe to investigate beinu asteroid
Fossil solar system
Benu (Bennu) has been closely monitored by astronomers since it was first discovered in 1999. It is 500 meters in diameter, surrounds the sun every 1.2 years and approaches the Earth every six years. NASA calculated that between 2175 and 2199, Benu was one in 2, 700.
However, this is not the only reason why NASA chose bernu among nearly 500000 asteroids. It is one of the oldest known asteroids, a remnant of the solar system at the beginning of its formation, and a fossil of the solar system. Taking dust samples from beinu, scientists can learn more about the original composition of the solar system.
At the end of 2018, NASA announced that the probe found traces of water on beinu, which was locked in the asteroid's clay. This suggests that there was liquid water in Bennu's mother body, a larger asteroid.
Benu is dangerous for OSIRIS-Rex. At first, scientists expected it to find an open piece of sand, because more than 2 centimeters of stone could cause obstacles. As a result, OSIRIS-Rex flew to Benu to find that the surface of the asteroid was covered with boulders, making it impossible to start.
However, engineers continue to enhance the autonomous navigation ability of the detector and narrow the target range. For this reason, Osiris Rex has continued to dive in the past period of time to take close-up photos and send back images to scientists for analysis.
Finally, the nightingale is located in a crater in the northern hemisphere of the asteroid. The crater is 140 meters in diameter. The image shows that the terrain is relatively smooth, cool and dark, which is conducive to the preservation of surface materials. The crater is suspected to be relatively young, the surface soil has only recently been exposed, and it is more likely to collect original samples.
Although the crater itself is 140 meters wide, for the detector, the safety range is only 16 meters, which requires a high accuracy of aiming. In addition, there is a huge rock on the eastern edge of the crater, which may pose a threat.
Sampling location "Nightingale"
In addition to the Nightingale, NASA has also circled an alternative location, the Osprey, in a smaller crater near the bernu equator. In any case, NASA engineers hope that the probe will be able to detect dangerous situations in time and get out of the way.
The sampling task is planned to be carried out in August 2020. Later, Osiris Rex will return with the spoils and return to earth in 2023.