NASA’s asteroid probe, the Source Spectroscopic Resource Safe Weathering Layer Identification Probe (OSIRIS-REx), will land on the asteroid Benu next year and collect rock and dust samples. According to the website of the British journal Nature, the probe’s landing sites on the asteroid have been selected: nightingales and Ospreys, respectively.
Since December 2018, OSIRIS-REx has been operating around Bennu, studying its surface and finding the safest landing location. Recently, project scientists announced their possible landing sites: the area called Nightingale and the area called Osprey. If all goes well, OSIRIS-REx will land at one of the sites, blowing up dust from the asteroid’s surface with nitrogen and collecting valuable samples, NASA said.
The spacecraft aims to collect samples in August 2020 and then return to Earth, where it will arrive in 2023.
Geologically speaking, landing on Benu is quite dangerous. OSIRIS-REx needs to fall into an open sandy area of the asteroid’s surface to avoid hitting any large rocks or adsorbed blocks larger than 2 cm (which can clog its filter). Mission scientists initially thought that the Benu surface was covered with sandy areas, so OSIRIS-REx could easily perform sampling tasks, but the results showed that Benu’s surface was covered with large rocks and had almost no open areas.
To land in a smaller target area (with a span of 16 meters, rather than the 50 meters that scientists had initially hoped for), mission engineers have been enhancing the spacecraft’s autonomous navigation capabilities. OSIRIS-REx will regularly photograph the asteroid’s surface as it descends, and then decide whether to proceed with the sampling mission. “I’m confident that we’ll get a sample,” said Dante Lauretta, the mission’s chief scientist. “
The Nightingale is located in a 70-meter-wide crater in the northern hemisphere of Benou, with a relatively cool and dark surface that looks like sand, while ospreys are located in a smaller crater closer to the equator.
OSIRIS-REx is NASA’s first asteroid sample return mission. Benu is a dark, primitive asteroid carrying water and other important chemicals from the early solar system.