NASA's asteroid chaser gets first glimpse of potentially hazardous target

A brightening Bennu is brought to you by the barnstorming OSIRIS-REx as NASA readies for a sample retrieval mission.

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Jackson Ryan was CNET's science editor, and a multiple award-winning one at that. Earlier, he'd been a scientist, but he realized he wasn't very happy sitting at a lab bench all day. Science writing, he realized, was the best job in the world -- it let him tell stories about space, the planet, climate change and the people working at the frontiers of human knowledge. He also owns a lot of ugly Christmas sweaters.
Jackson Ryan
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This artist's interpretation shows what Osiris-Rex might look like when it reaches Bennu.


NASA's OSIRIS-REx is hot on the tail of Bennu -- a 4.5 billion-year-old asteroid that has the potential to collide with Earth in the 22nd century.

Officially beginning "Asteroid Operations" in August, NASA's asteroid chasing spacecraft is slowing itself down for its arrival at asteroid Bennu on Dec. 3. In the meantime, NASA has provided a "tale of the tape" for its approach -- a series of images stitched together that documents OSIRIS-REx's approach.

Shot between Aug. 17 and Oct. 1, OSIRIS-REx's PolyCam imager snapped the obsidian black of the cosmos and a tiny, slowly brightening spot of light: 101955 Bennu. Over that period the spacecraft moved from 2.2 million kilometres away to a measly (in space terms) 192,000 kilometres, taking a snapshot every Monday, Wednesday and Friday (asteroid chasers -- and their engineers -- need weekends, too). That decreasing distance saw Bennu grow from 0.017 pixels to a whopping 0.19 pixels in size, giving us the following enticing but grainy photoset below.

That unprecedented look at Bennu was followed by another announcement -- with 55 days until OSIRIS-REx reaches its destination, it's now less than 100,000 km (62,137 miles) from the asteroid

Launched on Sept. 8, 2016, the Origins, Spectral Interpretation, Resource Identification, Security-Regolith Explorer  (OSIRIS-REx) aims to be the first US mission to bring back a sample from an asteroid. Provided all goes well, OSIRIS-REx will touch the surface of the asteroid, suction up some dust and debris and then jet back to Earth just in time for dinner -- in 2023. 

The seven-year mission is designed to give astronomers a more detailed history of the solar system -- and potentially it could even reveal the origins of life on Earth. One theory posits that the primordial beginnings of humanity may have been delivered here by an asteroid. I guess you never know, if you never go and NASA has decided to go. In addition, because Bennu poses a potential collision threat, chasing the asteroid through the cosmos could give us valuable information necessary to protect the Earth from celestial cannonballs.

While NASA continues to chase Bennu, the Japanese Space Agency, JAXA, is stationed out on the asteroid Ryugu. That mission aims to bring back samples by 2020, thanks to a pair of tiny hopping robots.

Explore asteroid Ryugu with Japan's Hayabusa 2 spacecraft

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