After orbiting the near-Earth asteroid Bennu for nearly two years, NASA’s OSIRIS-REx spacecraft is ready to reach out its robotic arm and collect a sample from the asteroid’s surface on Tuesday. That sample will be returned to Earth in 2023.
A van-size spacecraft has to briefly touch down its arm in a landing site called Nightingale. The site is the width of a few parking spaces. The arm will collect a sample between 2 ounces and 2 kilograms before backing away to safety.
“It’s a historic first mission for NASA, returning an asteroid sample, and it’s hard,” said Thomas Zurbuchen, associate administrator of NASA’s Science Mission Directorate, during a Monday press conference.
The site itself is nestled within a crater the size of a tennis court and ringed in building-size boulders.
Located more than 200 million miles from Earth, Bennu is a boulder-studded asteroid shaped like a spinning top and as tall as the Empire State Building. It’s a “rubble pile” asteroid, which is a grouping of rocks held together by gravity rather than a single object.
The mission — which stands for Origins, Spectral Interpretation, Resource Identification, Security-Regolith Explorer — launched in September 2016.
Since arriving at Bennu, the spacecraft and its cameras have been collecting and sending back data and images to help the team learn more about the asteroid’s composition and map the best potential landing sites to collect samples.
The main event of the mission, called the Touch-and-Go sample collection event, or TAG, is scheduled for October 20 beginning at 5 p.m. ET.
Bennu has an orbit that brings it close to Earth, which is why it’s considered to be a near-Earth asteroid. One of its future approaches could bring it perilously close to Earth sometime in the next century; it has a one in 2,700 chance of impacting our planet.
The samples from Bennu could help scientists understand not only more about asteroids that could impact Earth but also about how planets formed and life began.
“Bennu is almost a Rosetta Stone out there, and it tells the history of our Earth and solar system during the last billions of