NASA mission succeeded: DART probe changes orbit of asteroid Dimorphos

NASA's DART (Double Asteroid Redirection Test) mission has successfully changed the orbit of the asteroid Dimorph following a collision with it, NASA Administrator Bill Nelson said during a media briefing.

And this means that if necessary, we can protect the Earth from asteroid collisions.

Dimorphos after impact with DART probe

The asteroid Dimorphos revolves around the asteroid Didymus, and its rotation period before the DART probe impact was 11 hours and 55 minutes. On Sept. 26, the probe crashed into the asteroid, and since then scientists have been tracking changes in its orbit and speed using data from optical telescopes from around the world as well as radar images.

The results, as it turns out, have exceeded all expectations. According to the scientists' calculations, the collision should have changed the rotation time of the asteroid by about 73 seconds, but in fact, it has changed as much as 32 minutes and now lasts for 11 hours 23 minutes.

Every day scientists receive new data, which will help improve the accuracy of measurements. So far, the possible error in the calculations is estimated at 2 minutes.

What does it mean?

The results of this mission can be considered a turning point in the history of planetary defense, because they showed that the collision with the aircraft can really change the course of the asteroid.

Neither Dimorphos nor Didymus posed a threat to Earth, but the change in course of Dimorphos showed that in the future, if an asteroid dangerous to our planet appears, a probe like DART could change its orbit, thus protecting us from a collision with it.

Some scientists, however, speak of this with some caution. They say that while the mission confirmed that NASA has the technology to protect against a dangerous asteroid collision, there is no one hundred percent certainty that it will work as it should in the future.

“We have a lot of work ahead of us in order to really understand what happened,” said Tom Statler, a DART programme scientist at NASA’s headquarters in Washington DC.

As Nancy Chabot, DART coordination chief at the Johns Hopkins Applied Physics Laboratory (APL), noted, if the Earth should one day be threatened by a dangerous asteroid, extended studies of the asteroid will be needed, and a probe strike should be organized as early as possible - years before the expected impact with the Earth.

However, you are too early to start worrying because if anything NASA will take years to divert the asteroid from its course. The organization is actively inventorying all asteroids, and according to the data available, only 40 percent of the asteroids we know are large enough (about 140 meters) to cause regional damage to Earth. And a collision with none of them is not expected in the foreseeable future.

Next missions

Now NASA scientists are planning to find out what role the DART mission played in the emission of fragments and dust after the collision of the aircraft with the asteroid. It is believed that this ejection may have significantly affected the change in velocity of the asteroid – in about the same way that air coming out of a balloon pushes it forward.

In about four years, the Hera project of the European Space Agency plans to study both Dimorphos and Didymus. Particular attention will be paid to the crater that formed because of the collision with the DART probe. It is also planned to accurately measure the mass of Dimorphos.