The OSIRIS-REx team has decided on a location to collect a sample from the asteroid Bennu. It’s a 140-metre-wide crater that they’ve dubbed “Nightingale.”
This announcement follows a months-long selection process between four bird-named candidates: Sandpiper (specifically a western sandpiper), Osprey, Kingfisher (specifically a common kingfisher), and Nightingale, all of which seemed to be fairly hazard-free. Selecting the example sampling site is the next step for the mission.
OSIRIS REx’s researchers settled on the Nightingale site due to an abundance of fine-grained particles in an area where they’ll be easy (relatively speaking) to collect, Dante Lauretta, OSIRIS-REx principal investigator at the University of Arizona in Tucson, explained in a NASA press release.
The crater is 140 metres across on Bennu’s far-northern hemisphere. The location and relatively new age of the crater means that the material will hopefully be pristine—relatively unchanged since Bennu formed in the solar system’s early days. OSIRIS-REx will not land on the site; instead, it will approach the asteroid, touch it, grab a sample, ad go in less than five seconds. The ship will be capable of three collection attempts.
Bennu is a carbon-filled asteroid 492 meters in diameter, orbiting the Sun at about the same distance as Earth. This orbit brings it relatively close to us—close enough that NASA scientists calculate a 1-in-2,700 chance of the asteroid striking Earth between 2175 and 2199.
The OSIRIS-REx mission launched in September 2016 and arrived at Bennu last December. The mission is NASA’s first asteroid sample return mission, and if successful, it will bring back the largest sample of extraterrestrial material since the Apollo days. Material on carbonaceous asteroids like Bennu can serve as a record of the kind of matter present in the early solar system and perhaps answer questions as to the origin of water and life on Earth.
Nightingale crater isn’t without its hazards. The part of the crater safe for landing is only 16 metres across, and there’s a big boulder on the crater’s rim that might be a hazard after the sample collection, according to the NASA release. The OSIRIS-REx team selected Osprey as a backup site, in case the ship must abort its first touchdown attempt and disturbs Nightingale in the process.
As a birdwatcher myself, I am obviously elated by the choice of bird names for craters on an asteroid that itself is named after an Egyptian god depicted as a bird. Common nightingales are found in Europe, southwest Asia and northern Africa (but not in North or South America) and are famous for their beautiful song. I personally would have picked a songbird found in North America like the bobolink or the wood thrush, given that NASA is the U.S. space agency, but I am but an armchair astronomer.
After continuing to survey the asteroid and create high-resolution maps, the OSIRIS-REx team will plan rehearsals for its sample collection attempts. The spacecraft is due to depart Bennu in 2021, for a 2023 return to Earth.