A Spacecraft Deflects an Asteroid
NASA scientists want to nudge an asteroid off its course. To accomplish this task, they have studied busy harbors for clues as to how this could be accomplished, such as tugboats nudging large ships into wharves.
DART conducted a test impact against Dimorphos in September as part of its mission, shortening its orbit around larger companion Didymos but also showing unexpected changes on Dimorphos.
It’s a lot of fun
As space is vast and unforgiving, even small asteroids have an increased chance of colliding with something; such as an opposing spacecraft. But spacecraft typically feature thick shields designed to limit such collisions; even large rocks likely won’t do serious damage, according to astronomers.
NASA provided proof of this fact in 2022 when their Double Asteroid Redirection Test (DART) craft deliberately hit Dimorphos, an asteroid 560-feet wide and altered its orbit to turn into one that remains dangerous but no longer threatens Earth. The feat resulted in one that remains on an impact path but not as close.
Astronomers are currently studying the crash to gain more insight into why Dimorphos behaved as it did. According to reports, it appears the DART-Dimorphos collision released 37 new debris fragments that are now traveling toward Mars; should any hit Earth, these may leave behind craters as wide as 23 feet wide. Furthermore, scientists are investigating if Dimorphos disintegrated into multiple pieces; an action which would pose extreme risks during real asteroid deflection missions.
It’s a lot of work
NASA’s golf cart-sized Double Asteroid Redirection Test (DART), used as part of their first-of-its-kind experiment in September 2017, proved this technique works. DART struck an asteroid called Dimorphos to prove this theory works.
At 14,000 miles per hour, a 14,000 mph kinetic impact shifted an asteroid’s orbit around a larger object called Didymos. New studies prove the success of this experiment.
DART collision was an elastic one, meaning the spacecraft absorbed much of the asteroid’s kinetic energy instead of simply disintegrating it. Ejected material also served as an ephemeral rocket booster to increase momentum shift.
Astronomers were able to witness the aftermath of Dimorphos’ collision using a telescope, and saw its tail gradually grow longer – this looked much like the comet-like tails seen occasionally on other asteroids; and was the first time scientists could demonstrate impact could create such an effect.
It’s a lot of money
NASA’s asteroid deflection experiment — designed as a dress rehearsal against any future threats — went well, though not without significant financial costs.
DART was an expensive $325 million Double Asteroid Redirection Test designed to demonstrate how spacecraft can redirect an asteroid by colliding with it – known as “kinetic impact.” The one-way collision between the spacecraft and Dimorphos was intended to prove this strategy works and alter its trajectory.
Hollywood asteroid movies may depict nuclear bombs as the only effective solution, but experts in planetary defense believe a less drastic approach may be more appropriate: gently nudging any potentially hazardous asteroids just enough to avoid collision. While ramming an asteroid with a small spacecraft requires precise navigation and fuel, proving more effective than shooting bullets through it because impact would be easier to measure without needing two spacecraft as backup.
It’s a lot of risk
NASA’s Double Asteroid Redirection Test (DART) spacecraft made history when it intentionally altered Dimorphos’ course in September 2022 using its van-size Double Asteroid Redirection Test (DART). The impact shifted its orbit around its larger parent rock Didymos, speeding up and shortening revolution times to 11 hours 22 minutes instead of 12 hours 55 minutes.
At times, collisions between asteroids may also shatter and disperse some of their surfaces, increasing their risk of hitting Earth in the future. It all depends on their shape, mass, composition and velocity – typically, an object which hits with speeds above 14,000 miles per hour will disintegrate upon striking our planet before returning back into space as fragments.
Asteroid impacts could potentially bring global destruction, including possibly wiping out life on Earth. Therefore, United States and other space agencies have set themselves the goal of finding, cataloging and tracking 90% of asteroids larger than 1 km diameter that threaten our planet by 2008. But should these smaller rocks venture off into deep space without detection then finding and tracking them may prove more challenging than expected.