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Will an asteroid ever hit Earth? NASA scientist gives reassuring answer

Asteroids hit Earth all the time, but there's no reason to panic.

Amanda Kooser
Freelance writer Amanda C. Kooser covers gadgets and tech news with a twist for CNET. When not wallowing in weird gear and iPad apps for cats, she can be found tinkering with her 1956 DeSoto.
Amanda Kooser
2 min read
asteroidbennu

Asteroid Bennu has only a very, very slim chance of impacting Earth.

NASA/Goddard/University of Arizona

There's nothing quite like an alarmist headline about a big asteroid visiting Earth's neighborhood in space to get the blood pumping. Add in the popularity of space disaster movies like Armageddon, and you can understand why humanity might have an obsession with space rocks. So what does a NASA scientist have to say about it?

NASA released a short video Wednesday with scientist Kelly Fast, an asteroid expert working on planetary defense, answering the pressing question, "Will an asteroid ever hit Earth?"

Fast had a quick response: "Yes, asteroids have hit Earth over the course of its history and it will happen again." But don't panic, it doesn't happen very often, and we're getting better and better at spotting and tracking potential threats.

Bits of space rock and dust are constantly bashing into our atmosphere, giving us spectacular meteor showers to enjoy. Asteroids that affect the Earth's surface are much rarer. "They happen on time scales of hundreds to thousands to millions of years," Fast said.

In July, a team of researchers from the Southwest Research Institute calculated the type of asteroid that wiped out the dinosaurs like strikes Earth once in every 250 million years -- on average. That dinosaur death blast occurred some 66 million years ago, so the average is pretty good for life on Earth right now.

That doesn't mean scientists aren't keeping a close eye on some rocks, like asteroid Bennu. That spinning-top of a rock has a 1 in 1,750 chance of smacking Earth in the future. It's nothing to lose sleep over. In fact, here's a handy guide for when to actually fear space rocks. Spoiler: not very often.

NASA's Planetary Defense Coordination Office pointed out on Twitter that there are no known asteroid impact threats to Earth for the next century.

Explore asteroid Ryugu with Japan's Hayabusa 2 spacecraft

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Asteroids are still a concern, which is why NASA and other space agencies are working on ways to deal with potentially threatening objects. NASA is gearing up to launch its Double Asteroid Redirection Test (DART), a planetary defense mission that'll crash a spacecraft into a moonlet to see if it can change its path. If it works, the concept could be used to nudge a dangerous asteroid away from our planet.

So an asteroid will come for us someday, but hopefully we'll have plenty of warning and may even be able to do something about it.

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