ORLANDO, Fla. – A NASA spacecraft is less than two days away from sucking up a few pounds of a 4.5 billion-year-old asteroid called Bennu and bringing it back to Earth, enabling scientists to learn more about how planets formed and how to protect Earth from asteroids in the future.
This mission has been more than a decade in the making; OSIRIS-REx launched from Cape Canaveral Florida in September 2016. The spacecraft name stands for Origins, Spectral Interpretation, Resource Identification, Security, Regolith Explorer, a true mouthful even for a NASA acronym.
The spacecraft chased down its target, Bennu, and has been orbiting the asteroid since December 2018, preparing for the Oct. 20 sample collection from a spot on the space rock nicknamed Nightingale.
The 500-meter-wide asteroid was chosen for several reasons, including that it could one day-- in a very long time-- hit our home planet.
“It is not threatening Earth right now. But its orbit has the largest potential of evolving into one that would threaten Earth and that would happen in about 160 years,” University of Central Florida planetary scientist Humberto Campins said. “So, if we have to deflect Bennu or if we have to deflect another asteroid, like Ben, studying Bennu in detail will tell us a lot about how to do it.”
Campins is a member of the OSIRIS-REx science team and currently in Tucson, Arizona, at mission headquarters leading up to the sample collection. The NASA-funded mission is led by the University of Arizona.
Besides the benefit to Earth’s security, Bennu is also full of clues to how our planet and others formed.
“It’s a primitive asteroid, we think its surface or its material in general … has not been heated very much. And if it if it hasn’t been heated much, it preserves the same composition that it had when it formed about 4.5 billion years ago,” Campins said. “And so that itself tells us about the conditions in the solar nebula, this cloud of gas and dust that form the planets and the sun.”
On Tuesday around 6:12 p.m. ET OSIRIS-REx will swoop in, using its arm to “tag” the asteroid surface, stirring up some regolith and taking some with it before pushing away from Bennu. The maneuver is called a “touch and go," according to NASA.
If Tuesday’s attempt does not happen there are backup opportunities for the spacecraft to try again.
The spacecraft will drop off the sample to Earth in 2023 where it will then undergo analysis in labs at NASA’s Goddard Flight Center and elsewhere.
“Bringing the sample back to Earth means we can use much better equipment than we’re able to send to space,” Jamie Elsila, a research scientist at NASA Goddard Space Flight Center, said. “The instruments in my lab for example are much too big and use too much power and there’s way too much to be able to send it to state today these measurements at faster.”
However, a majority of the sample will be saved until new technology is developed by future generations.
“The mission is going to archive 75% of the returned material,” Elsila said. “That’s going to allow people not yet born, (to use) the techniques not yet invented, to answer questions not yet asked ... this new sample is going to provide important science information now, and also for generations to come."
Beyond OSIRIS-REx NASA is only ramping up its study of asteroids.
The space agency has two separate missions set to launch next year. NASA’s Double Asteroid Re-direction Test mission, or DART, is designed to test technology to prevent an impact of a hazardous asteroid. Another spacecraft nicknamed Lucy, is slated to launch in October 2021, will be bound for the Trojan Asteroids.