Infrared sensors on the bottom detected the warmth signature of the OSIRIS-REx spacecraft’s sample-return capsule when it slammed into the environment at greater than 45,000 km/h (27,650 mph), at 8:42 a.m. MDT right now. The 46 kg (101 lbs.) capsule was dropped off by its a lot bigger OSIRIS-REx mom ship as that spacecraft went whizzing briefly by Earth. The capsule hit the air off the coast of California, aiming for a parachute touchdown within the Division of Protection’s Utah Check and Coaching Vary southwest of Salt Lake Metropolis. Even earlier than the capsule landed, 4 search helicopters scrambled to satisfy it, and the folks at NASA waited anxiously to listen to that it had returned safely.
It had. The capsule thumped down at 8:55 a.m. MDT and the helicopter crews scooped it up and whisked it to a clean-room on the navy base, getting ready to ship it off to the Johnson Area Heart in Houston.
The scientists there could have rather a lot to have a look at. Sealed contained in the capsule are 250 gm (8.8 oz.) of rock and dirt from the asteroid Bennu—a 4.5 billion-year-old fossil of the traditional photo voltaic system that NASA has spent greater than $800 million and 7 years working to discover. The return of the pattern made OSIRIS-REx solely the third spacecraft—and the primary American one—to drag off the asteroid-spelunking trick, after Japan’s Hayabusa and Hayabusa 2 managed it in 2010 and 2020 respectively. Perceive the chemistry and historical past of Bennu’s mud and you may perceive the chemistry, historical past, and even origins of the photo voltaic system and the Earth—in addition to the life that calls our planet dwelling.
“It form of speaks to the explanations folks discover,” says Wealthy Burns, the OSIRIS-REx venture supervisor. “We are able to be taught in regards to the evolution of the photo voltaic system, why the Earth exists in its current state, why it’s particular. We are able to get on the query of the place we come from.”
Graphic by Lon Tweeten for TIME
Amassing that Bennu pattern was not straightforward. It was on Sept. 8, 2016, that OSIRIS-REx (quick for Origins, Spectral Interpretation, Useful resource Identification, Safety-Regolith Explorer) lifted off from Cape Canaveral in a round-about pursuit of Bennu. The asteroid is a small goal—simply 492 m (1,614 ft.) throughout—and circles the solar in roughly the identical orbit because the Earth. At its most distant, it’s about 300 million km (186 million mi.) from us. Essentially the most direct option to attain it could be to chop throughout the photo voltaic system in an as-the-crow-flies pursuit, intercepting Bennu on the opposite facet of the solar. However that might have seen the spacecraft approaching the rock at a 90-degree angle, blazing previous it at 19,300 km/h (12,000 mph). That’s high quality for the type of temporary, photographic flybys the Voyager spacecraft carried out of the outer planets within the Seventies and Nineteen Eighties; the OSIRIS-REx mission, nonetheless, referred to as for the spacecraft not simply to fly previous Bennu, however to enter a lazy orbit round it. To try this, the ship needed to make two full circuits across the solar, slowly catching as much as the asteroid and matching its velocity and trajectory. Throughout that point, OSIRIS-REx put greater than 2 billion km (1.24 billion mi.) on its odometer.
On Dec. 3, 2018, the spacecraft finally caught up with Bennu and fired its thrusters to enter orbit across the rock. It took barely a puff of propellant to try this, and it could take simply as little to drag away: Bennu’s gravity—to the extent that it has any in any respect—is 100,000 instances much less highly effective than that of Earth. Settled into the asteroid’s tenuous gravitational grip, the spacecraft started a distant surveying marketing campaign, utilizing its a number of on-board devices—together with three cameras, an infrared spectrometer, an X-ray imaging spectrometer, and a laser altimeter—to check Bennu’s mineral and elemental make-up. It additionally exhaustively mapped the asteroid’s floor, in search of a spot to gather its pattern. At some factors, OSIRIS-REx flew at altitudes as little as 1.6 km (0.99 mi.) above Bennu—the closest any spacecraft has ever gotten to any physique it was orbiting.
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Drawing so shut got here with perils. Bennu rotates on its axis as soon as each 4.3 hours—giving it 2.15 hours of sun-facing day, and a couple of.15 hours of space-facing evening. Throughout these transitions, the temperature on any given spot on the rock swings from 116°C (240°F) to -73°C (-100°F) and again once more. All these modifications in thermal stress make for lots of enlargement and contraction of the rocks and different rubble on the floor—sufficient to make them, successfully, leap off Bennu’s floor.
“It ended up trying like popcorn,” says Dante Lauretta, professor of planetary science on the College of Arizona and principal investigator on the OSIRIS-REx mission. “Each time we seemed we noticed stuff exploding off the floor. We have been saying, ‘Oh man, this could possibly be a hazardous setting for the spacecraft. We would need to again away and redesign the entire encounter.’” Finally the crew concluded that that wouldn’t be vital. It doesn’t take a lot power for small rocks to drag free from Bennu’s microgravity grip, so even when the rubble struck the spacecraft it wouldn’t be packing any significant wallop.
The entire up-close orbital scrutiny the rock obtained paid off: only a week after the spacecraft arrived at Bennu, NASA introduced that it had found the presence of hydrated—or chemically water-logged—minerals blended in with the soil. With no environment and its mere whisper of gravity, Bennu couldn’t harbor any deposits of pooling liquid, however the discovering of even traces of water does recommend that the rock was as soon as a part of a a lot greater mass—even perhaps a moon or planet—that did have muscle to hold onto its water.
“The pondering,” says Burns, “is that Bennu was half of a bigger mother or father physique that had a collisional occasion.”
It wasn’t till Oct. 20, 2020, almost two years after OSIRIS-REx arrived at Bennu, that the spacecraft started the capstone maneuver of its mission—descending that final mile to gather its pattern. NASA had narrowed the potential assortment websites right down to 4 candidates that it dubbed Sandpiper, Osprey, Kingfisher, and Nightingale—selecting these as a result of they’d the fewest rocky obstacles for the spacecraft’s descent, in addition to considerable unfastened soil to gather. Finally NASA decided that Nightingale—positioned in a crater excessive in Bennu’s north—was the most effective of that group.
Taking the pattern required the spacecraft to land briefly on Bennu, in a maneuver NASA named TAG, for touch-and-go. Within the 16 seconds OSIRIS-REx was on the floor, it prolonged its 3.3 m (10.8 ft.) robotic arm, which was outfitted with a set chamber on the finish. At that time, nitrogen bottles within the arm fired, blowing soil and unfastened pebbles right into a chamber. The lid to the chamber was then sealed and the dear pattern transferred to the return capsule. On Might 10, 2021, after finishing almost seven extra months of orbital surveying, OSIRIS-REx finally peeled off and headed again for Earth.
Learn extra: NASA Tried To Knock an Asteroid Off Course—And Succeeded Wildly Past Expectations
With the Bennu pattern now on the bottom, greater than 200 scientists from around the globe will set to work finding out it. Essentially the most intriguing questions they’re attempting to reply concern the function incoming asteroids might have performed in seeding the Earth with water, nitrogen, carbon, and different components vital for all times to take maintain.
The moon is believed to have shaped near 4.5 billion years in the past, when a Mars-sized planetesimal collided with Earth, throwing up a cloud of particles that coalesced right into a model new physique. Any oceans, a lot of the environment—and any potential earthly biology—which will have existed on our planet would have been worn out within the violence. “We predict the floor was utterly sterilized,” says Lauretta. For all times to reemerge, it could take asteroids crashing into Earth and resupplying it with the mandatory chemistry. Research of Bennu’s soil and rocks will assist present if asteroids certainly carry enough portions of these uncooked supplies within the first place.
And as for OSIRIS-REx itself, which didn’t even pause on this morning’s flyby of Earth? Initially, the spacecraft’s mission was supposed to finish after the sample-return capsule was launched. In April 2022, nonetheless, NASA introduced that it had different plans for the ship, and can be sending it off for a second orbital rendezvous, this time with the asteroid Apophis, after the 340-meter (1,100 ft.) rock makes an in depth strategy by Earth in 2029. OSIRIS-Rex will spend about 18 months at Apophis—and a few members of the crew are dreaming that it will not be completed even then.
“By no means say by no means,” says Lauretta. “I’m stepping down because the principal investigator and considered one of my mentees is taking up. I informed her, ‘Don’t break the spacecraft. It may need a 3rd asteroid in it.’”
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