NASA successfully crashed the Dart spacecraft into an asteroid in the first planetary defense mission

The POT it achieved a feat that humanity had never accomplished before: deliberately crashing a spacecraft into an asteroid to slightly deflect its orbit, a key test in demonstrating the ability to prevent cosmic objects from destroying life on Earth.

The mission DART (Double Asteroid Redirection Test) was launched from California in November and rapidly approached its target, hitting it at around 23,000 kilometers per hour.

To be safe, neither the asteroid Dydimos nor Dimorphos, the small asteroid that orbits it, pose a threat, as both revolve around the Sun, passing within billions of kilometers from Earth. But this experiment is considered important by the POTwho wants to do it before there is a real need.

“This is an exciting time, not just for the agency, but also for space history and human history.said Lindley Johnson, planetary defense officer for the POTat a briefing on Thursday.

If all goes according to plan, the impact between the spaceship -the size of a car- and the 160-meter asteroid -equivalent to two Statues of Liberty- will take place at 23:14 GMT on Monday and can be followed in a broadcast live from the POT.

Upon hitting Dimorphos head-on, the POT it hopes to push it into a lower orbit, reducing the time it takes to circle Didymos by ten minutes, from currently 11 hours and 55 minutes, a change that will be detected by ground-based telescopes in the coming days.

The experiment will bring to life something only done in science fiction, particularly in movies like “Armageddon” and “Don’t Look Up.”

a technical challenge

As the ship moves through space, autonomously in the final phase of the mission, like a homing missile, its main camera system, called DRACO, will begin transmitting the first images of Dimorphos.

“It will start as a small point of light and eventually it will expand and fill the entire field of view,” said Nancy Chabot, of the Johns Hopkins Applied Physics Laboratory (APL), which houses mission control.

Minutes later, a toaster-sized satellite called LICIACube, which separated from DART A couple of weeks ago, it will pass near the site to capture images of the collision and of the pulverized rock thrown up by the impact.

LICIACube shots will be sent back in the following weeks and months.

There will also be a number of telescopes, both on Earth and in space, observing the event, including the most powerful and recently orbited James Webb.

Finally, a complete picture of the system will be revealed when a European Space Agency mission called Hera arrives four years from now to study the surface of Dimorphos to measure its mass, something scientists can only guess at present.

future existential threat

Very few of the billions of asteroids and comets found in the solar system are considered potentially hazardous to Earth, and none in the next hundred years.

But “I assure you that if you wait long enough, there will be one”said Thomas Zurbuchen, NASA’s chief scientist.

That is known from the geological record. For example, the nearly ten kilometer wide Chicxulub asteroid struck Earth 66 million years ago, plunging the world into a long winter that led to the extinction of the dinosaurs along with 75% of species.

An asteroid the size of Dimorphsby contrast, would only cause a regional impact, such as devastating a city, albeit with a force greater than any nuclear bomb launched so far.

Scientists also hope to gain valuable new information about the nature of asteroids in general.

The amount of movement that DART generate about Dimorphs It will depend on whether the asteroid is solid rock or a “garbage heap” of rocks held together by mutual gravity, a property that is not yet known.

Its actual shape is also unknown: whether it’s more like a dog bone or a donut, but NASA engineers are confident that NASA’s SmartNav guidance system DART will hit the target.

If it fails, the POT he will have another chance in two years, as the spacecraft contains enough fuel for another try.

But if it succeeds, then it will be a first step towards the world being able to defend itself against a future existential threat, Chabot said.

Source: AFP