What happened to the Dimorphos asteroid after the violent impact of the DART spacecraft?

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We were all fascinated by the images of the impact of the DART spacecraft on Dimorfos on September 27.

But

after the collision?

On Tuesday afternoon, NASA officially announced that the mission was a success: the asteroid has been deflected.

We analyze the most important keys of this important milestone:

Witnesses to the collision

Under the barrage of information in which we live, it is not easy to follow an event that, although it initially attracts our attention, is soon submerged by newer and always abundant news.

Thus, we all attended

with the small Dimorphos asteroid on September 27, Teresa Guerrero informed us promptly and excellently in EL MUNDO.

But perhaps far fewer keep track of what is happening after impact.

However, many astronomers around the world continue to point their telescopes at this small double system made up of

, trying to capture the consequences of the collision.

Image of Dimorphs taken by DART two seconds before the collision.NASA

The latest images taken by DART, just before crashing into Dimorphs, show us the surface of the small asteroid in unprecedented detail.

and to be covered with rocks of various sizes.

The impact was then captured live on camera by LICIACube, an Italian mini-satellite traveling alongside DART with the primary goal of

while keeping a safe distance.

The LUCIACube images (one of them heading this article) showed us how the collision produced a large flash and the ejection of a large mass of debris into space.

After the expansion of the initial cloud, the debris formed large plumes that were observed simultaneously with

, it was the first simultaneous observation made by the two space telescopes.

These plumes are like large rays shooting in all directions, and are well visible in both the optical and near infrared, sometimes appearing slightly curved in space for which we still don't know why.

The collision observed simultaneously by Hubble and Webb.NASA/ESA/CSA/HST/JWST

like a comet

On October 3, the US institute NOIRLab reported that two days after the impact, its telescope installed in Chile, called SOAR, obtained a spectacular image of Dimorphs in which a debris tail of

is observed .

The ejecta is being pushed along by solar radiation pressure, forming something much like the tail of a comet.

All astronomers are amazed by the devastating effects that the impact of a spacecraft, which seems tiny, has had on the great mass of Dimorphs,

(somewhat less than the length of two football fields).

Plume of more than 10,000 km observed by SOAR.NOIRLab/NSF

Telescopes continue to observe how these large plumes of material behave and how they dissipate over time.

And

professional analysis of the thousands of images that have been taken from so many ground and space telescopes.

The aim is to estimate how much material has been removed from the asteroid, at what speed it has been expelled, if the ejection is made up of large rocks or fine dust, etc.

Orbit deviation

Let us remember that the DART mission constitutes the first test to try to modify the movement of an asteroid.

Studying the effects of the collision in detail, understanding the nature of the resulting ejection, will greatly help define the characteristics that

must have to be optimal in diverting the trajectory of an asteroid that is dangerously headed towards Earth. .

Dimorfos moves around Didymos following an orbit of approximately 1 kilometer in diameter.

It is estimated that DART, hitting Dimorphs head-on

, will slow the asteroid down (slow it down) by about 60 km/h, but this estimate is highly dependent on the density and microstructure of the asteroid's material. asteroid.

Reducing its orbital speed will cause Dimorphos to gradually get closer to its partner Didimos.

So to speak, the small moon will progressively fall and its orbital period will shorten.

This period, which was

, could be reduced by at least 1 minute due to the collision.

Even if the change seems very small, it should be very precisely measurable within a few weeks or a few months.

Let us also remember that the European Space Agency (ESA) is already working on the construction of a spacecraft, called HERA, whose mission will be to observe the dynamic effects of the impact and photograph the crater that DART must have left on the surface of Dimorphos.

and the arrival at the double asteroid for 2027.

Rafael Bachiller

is director of the National Astronomical Observatory (National Geographic Institute) and academic of the Royal Academy of Doctors of Spain.

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