NASA Will Need Your Help Mapping Asteroid Bennu

OSIRIS-REx captured these images of Bennu during its first close flight over the asteroid's north pole.
OSIRIS-REx captured these images of Bennu during its first close flight over the asteroid's north pole. (Image credit: NASA/Goddard/University of Arizona)

Your mission, should you choose to accept it, is simple — click on the boulders you see in a detailed image of a distant space rock.

That straightforward task could steer NASA's OSIRIS-REx mission toward a successful sample collection from an asteroid named Bennu. The team in charge of the spacecraft will have just six weeks between producing an extremely high-resolution map of Bennu's surface and choosing where precisely to gather a sample from that rock.

"It is a massive task to actually map every single boulder on the surface, and we just didn't know a better way to do it in the amount of time," Carina Bennett, an imaging processing engineer for the mission based at the University of Arizona, told "We basically really, truly need the help."

Related: Making Asteroid Images Look Great: How OSIRIS-REx's Team Creates Those Bennu Photos

So Bennett and her colleagues turned to CosmoQuest, a platform for crowdsourcing space science, for the extra eyes they need to complete the mapping in time. The Bennu mapping project will go live on the CosmoQuest site beginning in late April or early May. That's when asteroid buffs will be able to help NASA out, tagging the edges of boulders in detailed images of Bennu's surface.

The exact launch date for the project depends on precisely how long it takes the OSIRIS-REx team to compile the detailed global mosaics that will reveal the boulders in need of counting. (The spacecraft is currently working on the detailed survey that will produce the many different angles of imagery scientists need to build that global mosaic.)

Once the mosaic is complete, the clock starts ticking, with just six weeks to identify each boulder on the surface and produce a detailed hazard map of Bennu's surface. That information will be passed along to the team in charge of selecting where OSIRIS-REx will attempt to grab a sample so they can reduce the odds of the sampling apparatus floundering on boulders.

That's particularly important because Bennu has turned out to be a more complicated target than scientists thought before the spacecraft's approach. "It was significantly more rocky and bouldery than we expected," Bennett said.

So the team needs to be careful to avoid hazardous sites. A boulder 8 inches (21 centimeters) across, for instance, could clog the spacecraft's sampling mechanism. The apparatus works by blowing compressed air at the surface, so if it touches down off-kilter, it could be stuck at a tilt and simply blow the targeted sample away.

That's why the OSIRIS-REx team can't choose their sampling location until they consult with a comprehensive boulder tally — and with a team of amateurs from around the world. "I think the most interesting part is that you're actually contributing to a decision," Bennett said. "You can actually go and watch when we sample and potentially see some of the same areas and images that you might have actually counted."

But the mapping project doesn't end when the OSIRIS-REx team selects the sample site. There's science work to be done with the images as well. The work CosmoQuest volunteers do will help the OSIRIS-REx team study the size distribution of boulders, for example, and how light or dark they are.

Related: Diamond Asteroids: How Bennu and Ryugu Got Their Fancy Shapes

With that data in hand, scientists should be able to draw conclusions about how Bennu works. Maybe lighter rocks are smaller, suggesting they're made up of material that breaks apart more easily. Maybe the direction boulders point toward suggests that the asteroid is shaking them around its surface.

The team also wants to be able to compare these pre-sampling images with those that the spacecraft will gather after it snatches a piece of Bennu to bring home.

"We're taking in a massive amount of data," Bennett said. "Just eyes on images is incredibly valuable."

Email Meghan Bartels at or follow her @meghanbartels. Follow us on Twitter @Spacedotcom and on Facebook.

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Meghan Bartels
Senior Writer

Meghan is a senior writer at and has more than five years' experience as a science journalist based in New York City. She joined in July 2018, with previous writing published in outlets including Newsweek and Audubon. Meghan earned an MA in science journalism from New York University and a BA in classics from Georgetown University, and in her free time she enjoys reading and visiting museums. Follow her on Twitter at @meghanbartels.