And of course, today’s big news is that NASA has successfully crashed a spacecraft into an asteroid. It will be a few days before we know if that means that the Agency has passed the first-ever planetary defense test, but navigation was the hardest part of the test with many unknowns, so I’m calling this a success either way.

As the Washington Post reports, the violent end of the Double Asteroid Redirection Test (DART) spacecraft thrilled scientists and engineers at the Johns Hopkins University Applied Physics Laboratory in Laurel, Md., which operated the mission under a NASA contract.

This was NASA’s first demonstration of a potential planetary defense technique called a kinetic impactor. The idea is to give a hypothetically dangerous asteroid just enough of a blow to alter its orbital trajectory.

It took less than a year for DART to reach Dimorphos, which is the size of a stadium — or the Great Pyramid of Giza, as one scientist put it Monday — and is about 7 million miles from Earth at the moment. Dimorphos orbits a larger asteroid named Didymos. Neither poses a threat to our planet now or anytime in the foreseeable future unless, presumably, the asteroid gets upset at us and throws back a rock. If it’s any consolation to asteroid lovers, Dimorphos probably felt nothing, since DART was the size of a vending machine. But even small effects on an asteroid’s movement could prove a planet-saver. An early collision with an asteroid, if done early enough — say, 5 to 10 years in advance of its projected encounter with Earth — could be just enough to slow it down and make it miss.

It will take at least a couple of days to tell if the DART mission succeeded in slowing down the targeted asteroid, and to what degree it did so. Telescopes on Earth and in space observed the collision, as did a small instrument, called a CubeSat, that was deployed 15 days before impact.

As you can see in the video above, Dimorphos completely filled the frame as DART was approaching, until the spacecraft’s autonomous navigation led it to hit the bull’s eye. Then came a blank screen. DART had succeeded and ceased to exist.

“Impact confirmed for the world’s first planetary defense test mission,” NASA’s live-streamed broadcast announced.

Claims that just before impact a small yellow sign was noticed on the asteroid that said “baby on board” are reported as inaccurate, as do claims that it would be cheaper to send Bruce Willis and a bunch of other guys up there with a few suitcase nukes to blow it off course. Which gives me an idea for a movie…

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