Artist Steve Gribben illustrated his vision of the DART mission heading for Didymos, a near-Earth asteroid with a moonlet. Image courtesy of NASA/Johns Hopkins APL/Gribben.
By Brooke Edwards
Our area’s NASA Solar System Ambassador for the Jet Propulsion Laboratory
Think of all the asteroids flying around in space. Is it possible to prevent one from colliding with Earth? DART (Double Asteroid Redirection Test) will be launched by NASA later this month to find out.
The mission launches from Vandenberg Air Force Base in California on or after Nov. 24. SpaceX is once again contracted to launch a mission with a Falcon 9 rocket.
DART is a planetary defense test conducted by Johns Hopkins University Applied Physics Laboratory, with help from numerous NASA centers. The mission will be the first use of the Kinetic Impactor Test. During the test, an object is impacted to to change its motion in space.
DART’s destination is the binary near-Earth asteroid (65803) Didymos, which is 780 meters in size with a 160-meter mini asteroid, Dimorphos, orbiting it. This mini asteroid is also known as a moonlet. Scientists are hoping the impact of DART will change the orbit of Didymos’s moonlet. This binary asteroid is an ideal test target. Measuring the change in the smaller asteroid’s orbit around the larger asteroid is much easier than observing the change in a single asteroid’s orbit around the sun.
An onboard optical navigation system known as DRACO will feed images to its autonomous guidance system (no real-time instructions from Earth!), piloting DART to precisely impact with Dimorphos. The collision is expected to take place in late September 2022. At that time, Didymos will be about 6.835 million miles from Earth.
DART spacecraft will crash into the moonlet at a speed of just under 15,000 miles per hour, changing the speed of Dimorphos in its orbit around the larger asteroid by a fraction of one percent. This will alter the orbital period of the moonlet by several minutes, enough to be observed and measured by telescopes on Earth.
This impaction method might be one way to avoid future asteroid threats to Earth. It is only a matter of time before an asteroid too large to be stopped by our atmosphere encounters our planet. For all we know, DART’s mission may be occurring at the perfect time in history to avoid such a collision in the future.
Be sure to follow NASA on social media or visit NASA.gov for launch and mission updates.
