In two weeks time, NASA will usher in a brand-new era for the study of asteroids and the solar system.
This significant achievement was made possible by the Double Asteroid Redirection Test (DART) mission, which was just initiated in the autumn of last year. DART will intentionally crash with a tiny asteroid on September 26. This is one of the few instances in which the destruction of a spacecraft is the intended result.
The project is being carried out in the name of planetary defense, which tries to defend Earth from any possible asteroid impacts. Scientists have high hopes that a mission such as DART would be able to avoid a catastrophe in the event that a hazardous asteroid threatens the planet in the future.
“These objects are hurtling through space and have of course scarred the moon and, over time, also on Earth have had major impacts, have affected our history,” Thomas Zurbuchen, NASA’s associate administrator for science, said during a news conference held on Monday (Sept. 12).
“A series of new missions that we put in place are actually helping us understand and quantify those threats in an unprecedented fashion,” Zurbuchen added. “DART is a first mission to try to really bump out of the way an object of threat in a direct experiment.”
Nearly 30,000 asteroids are known to circulate around the solar system in the area of Earth, and their orbits have been recognized and plotted by scientists. All of those pebbles from space either never come into contact with Earth or are of a size that if they did, they would be destroyed by the heat of the atmosphere without causing any damage.
However, there is a possibility that Earth may be harmed in the future by an impact from an asteroid, and those who specialize in planetary defense want to be prepared in case of that eventuality. Earth has been hit many times throughout its history, with some of these causing catastrophic damage to the planet. It’s not an “if” this will happen again, but a “when”.
According to one popular notion, an impactor probe might reorient the orbit of a space rock in such a manner that it crossed the path of Earth at a point in time when the planet was a sufficient distance away from it.
This would allow scientists to avert a potential asteroid strike on the planet. However, when faced with a real-world scenario, scientists prefer to base their work on empirical evidence rather than theory alone.
This is where the spectacular destruction of DART comes into play. The spacecraft is about to collide with a minor asteroid known as Dimorphos, which orbits around a much bigger asteroid named Didymos every 11 hours and 55 minutes. (Neither of these asteroids presents any danger to Earth, and there is no way that DART can alter that.)
The collision between DART and Dimorphos should alter its orbit, in theory, shortening its whole cycle..
In the weeks that follow the collision, scientists based on Earth will spend their time monitoring the actual shift in the orbit of the moonlet to compare it with their projections. Because of this effort, scientists will have a better grasp of how asteroids react when they are hit by objects, which will help them calibrate any future missions to the appropriate level of orbital alteration.
During the press conference, Nancy Chabot, who is in charge of DART coordination at the Applied Physics Laboratory at Johns Hopkins University in Maryland, which is in charge of running the project, said the following:
“This isn’t just a one-off event.”
“We want to know what happened to Dimorphos, but more important, we want to understand what that means for potentially applying this technique in the future.” She adds.
Even while the stakes are very minor in comparison to any situation that may inspire an actual asteroid-deflecting expedition, the level of difficulty remains the same.
What are your backup plans in case things doesn’t go as planned? The experts in charge of the mission are quite certain that there will be something to see as long as the spacecraft successfully reaches its target.
“If DART collides with Dimorphos and then you don’t see any orbital period change, this would be exceptionally surprising,” Chabot said. “Just the amount of momentum that DART is bringing in on its own from the weight of the spacecraft slamming into Dimorphos is enough to shift its orbit in a measurable way.”
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