The asteroid Bennu, first discovered in September 1999, quickly gained unprecedented popularity among space rocks. Space agencies, including NASA, are watching the rogue space rock for two reasons. It is hoped that the ancient asteroid can inform scientists about the origin of life on earth. And more intriguingly, between 2175 and 2199, Bennu suffers a 1: 2,700 chance of landing on the planet – making it the second most dangerous known space rock.
For these reasons, NASA's OSIRIS-REx (Origins, Spectral Interpretation, Resource Identification, Security, Regolith Explorer) will attempt to obtain and return a sample of the near-Earth asteroid.
NASA has just announced that it has selected the last four site candidates for the ambitious return attempt for asteroids. [1
NASA had originally planned to select the last two locations after this point in the mission.
However, the first pictures of OSIRIS-REx showed that asteroid Bennu has a particularly rocky terrain.
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Since then, the boulder-filled topography of the asteroid has challenged the team to identify safe areas of probable material, which must be fine enough – less than 1 inch (2.5 cm). Diameter – so that the sampling mechanism of the spaceship can be recorded.
Dante Lauretta, chief investigator for NASA OSIRIS-REx, said, "We knew that Bennu would surprise us and prepared us for anything we could find.
"As Coping with the unknown requires flexibility, resources, and ingenuity for each fact-finding mission.
"The OSIRIS REx team has demonstrated these essential features to overcome the unexpected throughout the Bennu encounter."
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The NASA OSIRIS-REx mission will now spend four more months analyzing the four candidate sites in detail, focusing on regions of fine-grained, sample-capable material through high-resolution images from each potential location.
The original mission plan envisaged a sample site with a 25m radius.
But such rock-free locations There's no such size on Bennu, so NASA's target is 16 to 3 feet (5 to 10 meters) wide.
The four possible sample locations on Bennu are Nightingale, Kingfisher, Osprey and Sandpiper – all domestic birds in Egypt.
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The naming theme complements the other two Egyptian naming conventions of the mission. NASA said in a statement: "The last of these types – Saxum – is a new feature classification that the International Astronomical Union for early this year Bennu has introduced small, rocky asteroids like Ryugu and Bennu.
"These surface features on Bennu are named after mythological birds and bird-like creatures and complement the existing nominal theme of the mission, which is rooted in Egyptian mythology."