Since December 2018, the OSIRIS-REx spacecraft has mapped asteroid Bennu’s entire surface to identify the most accessible and safest spots for collecting a sample. Now, NASA’s OSIRIS-REx team has selected four potential sites for the federal agency’s first asteroid sample return mission and they are named after birds native to Egypt.
The four candidate sample sites, which are called Kingfisher, Nightingale, Osprey, and Sandpiper, will be studied in further detail in order to select the final two sites, a primary and a backup, in December, said a NASA press release.
Even though the amount of samplebale material hasn’t been determined in each site yet, all of them were evaluated to ensure that the OSIRIS-REx spacecraft will stay safe when it lands and gathers a sample from asteroid Bennu’s surface.
Nightingale is the northernmost site. There are multiple possible sampling regions. Nightingale contains mostly fine-grain, dark material and has the lowest albedo (reflection) and surface temperature of the four sites. pic.twitter.com/Q7qGCgAqNv
As the northern-most site, Nightingale is situated at 56 degrees north latitude on asteroid Bennu. There are many possible sampling regions in this site, which is located in a small crater surrounded by a larger crater that is 459 feet in diameter. Nightingale has mostly fine-grain, dark material and it has the lowest reflection (albedo) and surface temperature out of the four sites.
Kingfisher is located in a small crater near Bennu’s equator. It is surrounded by boulders, but the site itself is free of large rocks. Of the four sites, Kingfisher has the strongest signs for hydrated minerals. pic.twitter.com/USqBrlA83j
Located in a tiny crater near asteroid Bennu’s equator at 11 degrees north latitude, Kingfisher has the strongest spectral signature for hydrated minerals among the four sites. The crater, which has a diameter of 26 feet, is surrounded by boulders, even though the site itself doesn’t contain any large rocks.
Osprey is set in a small crater in Bennu’s equatorial region. There are several possible sampling regions. The diversity of rock types hints that the regolith within the site may be diverse. Osprey has the strongest spectral (visible light) signature of carbon-rich material. pic.twitter.com/1XGbbkuRWP
Osprey is set in a small crater that is also located in asteroid Bennu’s equatorial region. Many potential sampling regions are present in this site, which has the strongest spectral signature of carbon-rich material out of the four sites. Different rock types in the surrounding area also suggest that the regolith (layer of unconsolidated rocky material covering bedrock) within Osprey could be diverse.
Sandpiper is in Bennu’s southern hemisphere. The site is in a relatively flat area on the wall of a large crater. Hydrated minerals are present, which indicates that Sandpiper may contain water-rich material. pic.twitter.com/BvKfcHmuyA
Asteroid Bennu’s southern hemisphere is home to Sandpiper. Located at 47 degrees south latitude, this site is a relatively flat area on the wall of a large crater that is 207 feet in diameter. Sandpiper may also contain unmodified water-rich material, since hydrated minerals are also present at the site.
Stay tuned! These four sites will be studied in more detail by @OSIRISREx in order to select the final two sites – a primary and backup – for sample collection. Read more: https://t.co/ljXoEP4aHD pic.twitter.com/9a4riUaE28
Starting this fall, the OSIRIS-REx spacecraft will start analyzing the potential sites during the mission’s reconnaissance phase. The first stage of this phase will involve the OSIRIS-REx spacecraft executing high passes over each of the sites from a distance of 0.8 miles to confirm they contain sample-friendly material. Close-up images will also take note of the features required for the OSIRIS-REx spacecraft’s autonomous navigation to asteroid Bennu’s surface. Once data is collected from these passes, the team will choose the final primary and backup sample collection sites at the end of the year.
The second and third stages of reconnaissance are expected to start in early 2020, when the OSIRIS-REx spacecraft will conduct passes over the final two sites at lower altitudes and obtain higher resolution observations of asteroid Bennu’s surface, which will help it identify key features that will be used to navigate to the space rock’s surface for sample collection. OSIRIS-REx sample collection is scheduled to take place in late 2020 and the OSIRIS-REx spacecraft will return the asteroid samples to our planet on Sept. 24, 2023.