boxy spacecraft approaching large rock

An artist's depiction of the DART spacecraft approaching the asteroid Dimorphos. (Image credit: NASA/Johns Hopkins APL/Steve Gribben)

Don't let your guard down for impact.

The Double Asteroid Redirection Test will reach its target tonight. The time was at 7:14 pm. If everything goes well, DART will crash into Dimorphos in order to change the moonlet's trajectory. The purpose of the mission is to find out if this technique can be used to divert an asteroid.

The results of the DART mission will provide crucial data for scientists and engineers to develop plans for planetary defense, even though Dimorphos and Didymos aren't threats to our planet. DART is the first ever planetary defense test.

Lindley Johnson, NASA's planetary defense officer, said in a news conference that this is an exciting time for the agency. The demonstration is important to the future of our planet.

There are 8 ways to stop an asteroid.

DART has traveled 7 million miles to Didymos and Dimorphos since it was launched in November of 2011.

As DART approaches Dimorphos, it will use its sole instrument to autonomously navigate to its impact zone. It's not easy to estimate the diameter of Dimorphos.

Tom Statler, the program scientist at NASA, said at the news conference thatmorphos is a tiny asteroid. We don't know what it is, we don't know what shape it is. The technical challenges of DART are caused by that. It's difficult to hit an asteroid.

Elena Adams said that DRACO wouldn't even see Dimorphos until about an hour before impact. Adams said that at three minutes prior to impact and two minutes prior to impact, it's 42dpi.

As DRACO approaches Dimorphos at a speed of 14,760 mph, NASA expects it to send down one image per second. The public will be able to watch those images in real-time. Additional live coverage of the event will be broadcasted by NASA. The sun goes down at 2200GMT. You can watch the broadcasts on Space.com, NASA TV, NASA's website, and NASA's social media channels. The news conference will be held at 8 pm. The sun rises at 0000GMT.

The engineering team will be celebrating, and the astronomer will say, "OK, time to get to work."

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