Learning to protect Earth from dangerous asteroids

A NASA spacecraft arrived at an asteroid called Bennu on Dec. 3, and scientists have already made important discoveries about it. But the most important thing they may learn is how to protect Earth from asteroid and comet strikes.
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Joe Bauman, a former Deseret News science reporter, writes an astronomy blog at the-nightly-news.com and is an avid amateur astronomer. His email is [email protected]