“Mosaic of images showing Bennu’s rotation.” OSIRIS-REx, NASA, 2018. Public Domain. Included with appreciation.

September – a good month for rock collecting. In September 1999, asteroid 101955 Bennu was first spotted by the collaborative team of NASA, the U.S. Air Force, and MIT’s Lincoln Laboratory, working together under acronym LINEAR.  In addition to Bennu, the consortium discovered 140,00 minor planets, several comets, and some asteroids. A few of these celestial orbiters are potential unwanted visitors to Earth: Bennu could crash into our planet in September 2182. But NASA did not want to wait that long.

OSIRIS-REx, mission logo. By NASA 2011. Public Domain. Included with appreciation.

In 2018, the OSIRIS-REx (Origins, Spectral Interpretation, Resource Identification, and Security – Regolith Explorer) spacecraft launched, aiming for Bennu. It took two years to arrive, and then land on Bennu in October 2020 to collect samples. The landing was brief, called a “pogo stick:” a brief impact to plunge in and grab a sample to be returned to the spacecraft, and eventually to Earth. In September 2023, OSIRIS-REx flew near Earth to release a capsule containing Bennu samples to a landing spot in Utah, USA. The gift was promptly scooped up by a waiting NASA team and carefully loaded onto a special vehicle to bring it to a “clean room” with a continuous supply of nitrogen. Why nitrogen? It’s a gas that does not mingle or interact with most chemicals so keeping the capsule continuously bathed in nitrogen will wash away any earthly contaminants picked up en route and during the Utah landing.

Bennu, like Earth, orbits the sun. Bennu’s year is similar to Earth’s, with a year just 19 days longer than ours. “Animation of Bennu’s orbit around Earth” by graphic artist Phoenix 7777. Creative Commons 4.0. Included with appreciation.

Today, 25 September, the capsule will continue its journey aboard an aircraft headed for the Johnson Space Center in Houston. The gift will be shared: NASA scientists will evaluate samples and distribute them globally to the space community. It should be noted that Bennu is not the first asteroid to be sampled and brought to Earth. In 2010, Japan returned asteroid particles from Itowaka (also identified by LINEAR). A sequel mission visited carbonaceous asteroid Ryugu to collect samples during the Hayabusa2 mission, bringing the collection to Earth in 2020. Ryugu’s specimens were also shared worldwide. Asteroids, now more visible with the James Webb Space Telescope, may be the next chapter in space exploration.

Asteroids, now more visible with the James Webb Space Telescope (JWST), may be the next chapter in space exploration. Image: “Asteroid 6481 Tenzing” by JWST, 2022. Public Domain. Included with appreciation.

Why are asteroids (the word means “star-like”) important? And, why Bennu? Bennu is a carbonaceous asteroid with a diameter of 490 miles (788 kilometers). It’s dotted with boulders, some more than 50 miles (80 kilometers) in span. Of interest is Bennu’s probable possession of water. According to Professor Dante Lauretta of the University of Arizona,  principal mission investigator and also chief scientist for the Peace Satellite Project, water would be the prize. Bennu could be a celestial “filling station” providing water for various uses including the production of hydrogen rocket fuel. While the surface water may evaporate, traces could remain, allowing NASA to assess the amount of water on and in Bennu. In addition to water, Bennu may contain valuable information about the origins of the universe.

Bennu, Egyptian deity, named after the Bennu Falcon that stands as tall as a human. Image: Egyptian papyrus, photographed by Cobrenet, 2007. Public Domain. Included with appreciation.

What’s in a name? Bennu is an Egyptian deity in the form of a bird, often depicted as a heron. The name was the winner in a contest sponsored by the University of Arizona, along with LINEAR and The Planetary Society. It was a global contest, yielding 8,000 entries. The winner, and proud namer of the asteroid, was a third-grader Michael Puzio who attended school in North Carolina, USA. Following Puzio’s theme, NASA has named all of Bennu’s features after birds. The landing site was Nightingale, and a back-up location named Osprey. Interestingly, Japan’s Hayabusa spacecraft was named for a falcon. And, of course, the USA’s first lunar lander of Apollo 11 was called Eagle.

Apollo 11’s Lunar Lander was named “Eagle.” Image: “Animated eagle” by Rovsen.vahabov, 2017. Creative Commons 4.0. Included with appreciation.

Do you think naming space – celestial bodies as well as exploration missions and vehicles – should be open to the world’s students and citizen scientists? What would you name the next asteroid to be explored?

What would you name the next asteroid to be explored? Graphic by Eviatar Bach, 2011. Public Domain. Included with appreciation.

Bartels, Meghan. “Touchdown! Incredible Photos Show 2nd Asteroid Landing by Japan’s Hayabusa1.” 11 July 2019. Space.com. https://www.space.com/incredible-asteroid-n

Brooke, K. Lusk. “SPACE: Hayabusa Touchdown on Ryugu.” 21 September 2018. https://blogs.umb.edu/buildingtheworld/2018/09/21/space-hayabusa-touchdown-on-ryugu/

Fox, Karen, Alana Johnson, Rani Gran, Rob Garner. “NASA’s First Asteroid Sample Has Landed, Now Secure in Clean Room.” 24 September 2023. NASA. https://www.nasa.gob/press-release/nasa-s-first-asteroid-sample-has-landed-now-secure-in-clean-room

Lauretta, Dante S., et al., “OSIRIS-REx: Sample Return from Asteroid (101955) Bennu.” 22 February 2017. Space Science Reviews, Volume 212, Issue 1-2, pages 925-964. https://link.springer.com/article/10.1007/s11214-01700405-1

Wall, Mike. “9-Year-Old Names Asteroid ‘Bennu’ for NASA Mission.” 1 May 2013. Space.com. https://www.space.com/20923-nine-year-old-names-asteroid.html

Building the World Blog by Kathleen Lusk Brooke and Zoe G. Quinn is licensed under a Creative Commons Attribution-NonCommercial-NoDerivs 3.0 U