DART

On November 24th, 2021, most people in the United States were preparing for Thanksgiving, traveling across the nation, and figuring out what to cook for their big feast. NASA, though, had different plans: to launch a cube-like spacecraft that will purposefully crash into an asteroid 6.8 million miles from Earth.

NASA estimates there are around 25,000 near-Earth objects (NEOs) that are 460 feet or longer in diameter, which is large enough to cause mass devastation on Earth upon impact. While no known NEOs have a significant chance to impact the planet in the next 100 years, NASA estimates only around 40% have been discovered. This is where planetary defense comes in. One of the possible methods to defend our planet from an asteroid is by changing the trajectory of the object. A way to do this is to crash something significant into the object so that its trajectory is altered slightly to not hit Earth.

NASA is testing this by crashing the Double Asteroid Redirection Test (DART) spacecraft into an asteroid called Dimorphous. Around 560 feet in diameter, Dimorphus is around the height of the Great Pyramids, and orbits another, larger asteroid called 65803 Didymos, which has a diameter of around 2600 feet. The DART spacecraft was launched on November 24, 2021, inside a SpaceX Falcon 9 rocket from the Vandenberg Space Force Base in California. The size of a vending machine, the spacecraft is not expected to destroy Dimorphos but to change its orbit slightly upon contact in September 2022. To locate its target, DART will use an onboard camera called DRACO, along with, according to NASA, sophisticated autonomous navigation software. The impact is expected to change the orbital period of Dimorphos for several minutes, enough to be detected by telescopes on Earth. Another spacecraft, the Light Italian CubeSat for Imaging of Asteroids (LICIACube), will witness the DART impact and take photos of Dimorphos after the collision.

Overall, the DART mission will be an interesting experiment for the mechanics of deflecting an asteroid and will be a good first look at whether the method is feasible to protect our planet.