Elain Brown Science 08.29.2022 02:Aug AM EDT

NASA’s DART Mission Confirms Testing a Spacecraft to Crash an Asteroid

NASA's DART mission is ready to launch towards its asteroid target, being the first attempt ever made anywhere in the world to alter the speed and trajectory of the motion of an asteroid while it is in space.

The mission will prove that a spacecraft can independently traverse to a kinetic impact on a relatively small target asteroid. Once launched, this mission will demonstrate a feasible method to deflect an asteroid that comes close to possibly colliding with Earth.

This mission is expected to collide with an asteroid named Dimorphos. However, NASA is not just watching Dimorphus; it is also closely observing a nearby and much larger asteroid called Didymos. It has been noted that both Didymos and Dimorphos will pose a threat to the planet.

The purpose of this experiment is to determine whether or not this plan would be successful in the event that a potentially hazardous asteroid was observed heading in the direction of Earth.

NASA Deploys DART To Target Dimorphos

Last month, NASA's DART mission team just concluded a six-night observation campaign to validate earlier estimations of Dimorphos' orbit around Didymos, its larger parent asteroid.

The observation, which was carried out with some of the most powerful telescopes in the world, provided evidence that the asteroid will be placed in the predicted spot when it makes contact.

According to Digital Trends, NASA's Andy Rivkin, the DART investigation team co-lead, stated, "The measurements the team made in early 2021 were critical for making sure that DART arrived at the right place and the right time for its kinetic impact into Dimorphos."

Rivkin added, "Confirming those measurements with new observations shows us that we don't need any course changes and we're already right on target."

However, understanding the dynamics of Dimorphos' orbit is important for reasons beyond ensuring DART's impact.

If DART is successful in changing Dimorphos' trajectory, the moonlet will approach Didymos and orbit it more quickly. It is simple to measure that change, but researchers must be certain that the orbit is only being affected by the hit.

This includes more subtle forces such as radiation recoiling from the surface of the asteroid as it is heated by the sun, which can exert a slight strain on the asteroid and cause its orbit to shift slightly.

Asteroids Didymos and Dimorphos Closely Approaching Earth

According to NASA, Didymos and Dimorphos will reach their nearest approach to Earth in recent years at the end of September or the beginning of October. The asteroids are estimated to be approximately 6.7 million miles away. This is also the time when DART will aim to make an impact.

Due to its great distance from Earth, most ground-based telescopes have been unable to observe the Didymos system since March 2021.

However, in early July of this year, the DART Investigation Team used powerful telescopes in Chile and Arizona to monitor the asteroid system and look for adjustments in its brightness.

These shifts, which are referred to as "mutual events," take place when one of the asteroids moves in front of the other as a result of the orbit of Dimorphos, which causes some of the light that they emit to be blocked.

The ability to precisely calculate the length of time it takes Dimorphos to orbit the larger asteroid allowed researchers to forecast where Dimorphos would be at various times, including when DART impacts. DART is expected to accomplish its mission on September 26, 2022.