After a four-year journey, a NASA spacecraft touched down on the rugged surface of the Bennu asteroid on Tuesday, grabbing a sample of rocks dating back to the birth of solar system to bring home, reported Reuters.
The minivan-sized OSIRIS-REx spacecraft, built by Lockheed Martin, extended its 11-foot (3.35 m) robotic arm toward a flat patch of gravel near Bennu’s north pole and plucked the sample of rocks, the space agency’s first handful of pristine asteroid rocks.
“Sample collection is complete, and the back-away burn has executed,” Lockheed mission operator Estelle Church added seconds later, confirming the spacecraft eased away from the space rock after making contact.
The probe will send back images of the sample collection on Wednesday and throughout the week so scientists can examine how much material was retrieved and determine whether the probe will need to make another collection attempt.
If a successful collection is confirmed, the spacecraft will journey back toward Earth, arriving in 2023.
Japan is the only other country to have already accomplished this. The country managed with its Hayabusa2 probe to collect some dust from another asteroid, Ryugu, and is now on its way home.
Bennu, located over 100 million miles from Earth and whose acorn-shaped body formed in the early days of our solar system, could hold clues to the origins of life on Earth, scientists say.
“Everything went just exactly perfect,” Dante Lauretta, OSIRIS-REx principal investigator from the University of Arizona, Tucson, said on a NASA live feed from Lockheed’s mission support building. “We have overcome the amazing challenges that this asteroid has thrown at us, and the spacecraft appears to have operated flawlessly.”
The robotic arm’s collection device, shaped like an oversized shower head, is designed to release a pressurized gas to kick up debris.
The spacecraft was launched in 2016 from Kennedy Space Center for the journey to Bennu. It has been in orbit around the asteroid for nearly two years preparing for the “touch and go” manoeuvre.
“A lot of things could go wrong because the spacecraft’s about the size of a van, and the asteroid has a lot of boulders in it,” Lucy Lim, a planetary scientist at NASA, said in an earlier interview. “So we have to go between the boulders to get our sample, and a lot of planning went into that.”
NASA chose this particular asteroid because it is conveniently close and also ancient. Scientists calculated it formed in the first 10 million years of our solar system’s history, 4.5 billion years ago.
After Osiris-Rex reached the rock at the end of 2018, the scientists were surprised to receive photographs showing that it was covered with pebbles and boulders sometimes 30 meters high.
They have since mapped the asteroid to centimetre resolution, and chosen the least risky landing site: it is called Nightingale Crater, 25 meters (80 feet) wide, with a target zone just eight meters (26 feet) in diameter for the “kiss.”
It’s “almost a Rosetta stone, something that’s out there and tells the history of our entire Earth, of the solar system during the last billions of years,” said NASA’s chief scientist, Thomas Zurbuchen.
The samples will return to Earth on September 24, 2023, with a planned landing in the Utah desert.
Asteroids are among the leftover debris from the solar system’s formation some 4.5 billion years ago. Scientists believe asteroids and comets crashing into early Earth may have delivered organic compounds and water that seeded the planet for life. Atomic-level analysis of samples from Bennu could provide key evidence to support that hypothesis.
With additional inputs from AFP