I bet the dinosaurs would have liked to think of that.
On Monday, NASA will attempt a feat humanity has never accomplished before: deliberately ramming a spacecraft into an asteroid to slightly deviate its orbit, in a key test of our ability to stop cosmic objects from devastating life on Earth. .
The Double Asteroid Redirection Test (DART) spacecraft launched from California last November and is rapidly closing in on its target, which it will hit at around 14,000 miles per hour (23,000 km/h).
Certainly neither the Moonlet asteroid Dimorphos nor the big brother it orbits, called Didymos, pose a threat as the pair loop around the Sun, passing about seven million miles from Earth as they approach. the closest.
But the experiment is one that NASA felt was important to perform before a real need was discovered.
“This is an exciting time, not just for the agency, but in the history of space and in the history of humanity quite frankly,” Lindley Johnson, planetary defense officer for the agency, told reporters. NASA, during a briefing Thursday.
If all goes as planned, the impact between the car-sized spacecraft and the 530-foot (160-meter or two Statues of Liberty) asteroid is expected to take place on September 26 at 7:14 p.m. from the East (23:14 GMT), and can be followed on a NASA livestream.
By hitting Dimorphos head-on, NASA hopes to push it into a smaller orbit, slashing the time it takes to circle Didymos by ten minutes from the current 11 hours and 55 minutes – a change that will be detected by telescopes at soil in the following days.
The proof-of-concept experiment will materialize what has only been attempted before in science fiction, including films such as “Armageddon” and “Don’t Look Up.”
technically difficult
As the craft rockets through space, flying autonomously for the final phase of the mission like a self-guided missile, its main camera system, called DRACO, will begin transmitting the very first images of Dimorphos.
“It’s going to start out as a small point of light and then it’ll zoom in and fill the entire field of view,” Nancy Chabot of the Johns Hopkins Applied Physics Laboratory (APL), which hosts Mission Control, said in a recent briefing. .
“These images will continue until they cease,” added the planetary scientist.
A few minutes later, a toaster-sized satellite called LICIACube, which separated from DART a few weeks earlier, will pass the site closely to capture images of the collision and ejecta – the pulverized rock thrown by the impact.
LICIACube’s photo will be sent back in the following weeks and months.
Also watching the event: a network of telescopes, both on Earth and in space, including the recently operational James Webb, which may be able to see an illuminating dust cloud.
Finally, a full picture of what the system looks like will be revealed when a European Space Agency mission called Hera in four years arrives to survey Dimorphos’ surface and measure its mass, which scientists can only currently guess at.
In preparation
Of the billions of asteroids and comets in our solar system, very few are considered potentially dangerous to our planet, and none within the next hundred years.
But “I guarantee you that if you wait long enough, there will be an object,” NASA chief scientist Thomas Zurbuchen said.
We know that from the geological record, for example, the six-mile-wide asteroid Chicxulub hit Earth 66 million years ago, plunging the world into a long winter that led to mass extinction dinosaurs as well as 75% of species.
A Dimorphos-sized asteroid, on the other hand, would only have a regional impact, like devastating a city, but with greater force than any nuclear bomb in history.
Scientists also hope to glean valuable new information that can inform them more generally about the nature of asteroids.
The amount of momentum DART imparts to Dimorphos will depend on whether the asteroid is solid rock, or rather a “garbage pile” of rocks bound together by mutual gravity, a property that is not yet known.
We also don’t know its actual shape: whether it’s more of a dog bone or a donut, but NASA engineers are confident that DART’s SmartNav guidance system will hit its target.
If it fails, NASA will have another shot in two years, with the spacecraft containing just enough fuel for one more pass.
But if he succeeds, then it’s a first step towards a world capable of defending itself from a future existential threat, Chabot said.
NASA will crash a spacecraft into a 525-foot-wide asteroid in September. Here’s how to watch it
© 2022 AFP
Quote: NASA prepares to deflect asteroid, in key planetary defense test (2022, September 23) Retrieved September 23, 2022 from https://phys.org/news/2022-09-nasa-gears- deflect-asteroid-key.html
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