NASA plans to use the OSIRIS-REx probe to collect samples from the asteroid Bennu next year and last week unveiled four candidate sampling sites,media reported. The Space Agency announced Thursday that the OSIRIS-REx probe will try to collect samples from the 20-meter-wide crater, Nightingale.
Engineers selected Nightingale from four of Bennu’s final candidate sites, suggesting that this could be the best place to discover organic matter and water that may have originated in the early solar system on asteroids. “Because of the value of science, this site is ultimately the first choice,” Dante Lauretta, lead researcher on the asteroid sampling mission, said in a press release. However, targeting craters is not without risk. The area is surrounded by a huge rock wall, which can make it difficult to capture samples. But in the end, Lauretta says, the area may have what they’re looking for.
Scientists hope to obtain a sample that provides the best “snapshot” of what the solar system looked like when it first formed billions of years ago. The asteroid is thought to be a rock remain of the early solar system, relatively unchanged over time, and still contains material that existed during the planet’s birth. Studying the material supplied by asteroids in a laboratory on Earth can help us understand some of the secrets of how the universe formed.
The OSIRIS-REx probe is a robot responsible for capturing these asteroid particles and bringing them back to Earth. The probe has been circling around Bennu for the past two years. During this time, the spacecraft has been using various instruments to map Bennu’s surface and to learn more about its terrain. In this way, the Engineering team of the OSIRIS-REx team can select the best sampling location for the probe.
The rugged terrain of the asteroid Bennu proved to be different from what NASA engineers had expected. There are hundreds of boulders lurking on asteroids, and smooth areas are barely visible. This makes it extremely difficult to find the best sampling location. To collect material from Bennu, OSIRIS-REx is equipped with a tiny robotic arm designed to protrude from the probe and gently tap the asteroid, sending the emitted particles into the probe’s sample room.
The OSIRIS-REx team had only one chance to sample Bennu, so selecting the site was an extremely important part of the task. After drawing the surface, the engineer searches the image and uses algorithms and software to find the flat part of Bennu. NASA has even appealed to the public to help find possible targets. After identifying 50 potential sites, the OSIRIS-REx team eventually reduced them to four and eventually selected the Nightingale crater.
Nightingale is full of many fine particulate matter, but there are also some larger boulders, making it one of the risky targets. But scientists think it’s worth trying. First, the crater is located at the northernmost tip of the asteroid, where temperatures are lower than in other regions. The cold temperatures may have kept the material in the crater intact. In addition, the OSIRIS-REx team believes the crater is relatively new, so the material in the area has actually been inside Bennu for a long time and was not discovered until recently. This also means that the material may remain relatively constant,
Because of the risks of sampling Nightingale, the OSIRIS-REx spacecraft must be particularly accurate when it descends to the surface of an asteroid. The boulders surrounding the site could cause the spacecraft to tilt and then accidentally crash into the rock as it tries to leave the asteroid. One of the rocks is even nicknamed Mount Doom because it is particularly tall and steep. “It’s a huge building-sized barrier, and we’re trying to get into a crater about the width of several parking lots,” Lauretta said. Therefore, we know that there is danger around us. Be especially careful, the team added additional security measures to program the spacecraft to detect whether it would fall on a rocky surface. “If this does happen, the team will target a backup site called Osprey.
Currently, NASA hopes to collect samples from Nightingale in the summer of 2020, with the goal of collecting at least 60 grams of material. Once the samples are obtained, OSIRIS-REx will return to Earth in 2021 and attempt to land in the Utah desert in 2023. If the sample does contain water and organic matter as the team would have hoped, this could be important evidence of how life develops.