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    An ancient relic of our solar system’s early days, Bennu has seen more than 4.5 billion years of history. Scientists think that within 10 million years of our solar system’s formation, Bennu’s present-day composition was already established.

    Bennu likely broke off from a much larger carbon-rich asteroid about 700 million to 2 billion years ago. It likely formed in the Main Asteroid Belt between Mars and Jupiter, and has drifted much closer to Earth since then. Because its materials are so old, Bennu may contain organic molecules similar to those that could have been involved with the start of life on Earth.

    Go farther. Explore Bennu In Depth ›

    Ten Things to Know About 101995 Bennu

    10 Need-to-Know Things About Bennu

    1

    Found in 1999

    The asteroid was discovered by the Lincoln Near-Earth Asteroid Research (LINEAR) survey on September 11, 1999.

    2

    Named by 9-year-old

    Bennu’s original designation was 1999 RQ36. In 2013, a third-grade student named Michael Puzio won a contest to name the asteroid.

    3

    Far from home

    Bennu has drifted into near-Earth space because of gravitational interactions with giant planets and the gentle push of heating from the Sun. 

    4

    Low density

    Bennu's density is only about 30 percent more than water. This suggests the asteroid is probably a loose collection of rocks, like a pile of rubble.

    5

    Wave every 6 years

    Bennu has a close approach to Earth every six years. 

    6

    Potentially hazardous

    Scientists estimate Bennu has a 1‐in‐2,700 chance of impacting the Earth during one of its close approaches to the Earth in the late 22nd century.

    7

    burn up or bolt?

    Bennu may burn up in the Sun. Over millions of years, of all of the planets, Bennu is most likely to hit Venus

    8

    Big Boulder

    The boulder that juts from Bennu's south pole is about 164 feet (50 meters) high and 180 feet (55 meters) wide.

    9

    Moonless

    Although some asteroids have moons, Bennu does not.

    10

    More to come soon

    NASA’s OSIRIS-REx mission will reveal Bennu in unprecedented detail. It will collect a sample and return it to Earth in 2023.

    FAQ

    FAQ: Why Bennu?

    Bennu is close to Earth, it's really old and well-preserved. It might even help us in our search for clues to the origins of life—and learn how to preserve life by keeping near-Earth asteroids at bay. Read all 10 reasons scientists chose to go to Bennu ›

    Pioneer 10 Model

    Pioneer 10 Model

    Pioneer 10 was first through the asteroid belt and first to Jupiter.

    Resources

    Resources

    OSIRIS-REx mission homepage: https://www.asteroidmission.org/

    NASA OSIRIS-REx page: https://www.nasa.gov/osiris-rex

    More about OSIRIS-REx: https://nssdc.gsfc.nasa.gov/nmc/spacecraftDisplay.do?id=2016-055A

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