NASA plans to ram a spacecraft into an asteroid in hopes of redirecting its orbit as part of a future planetary defense plan.
what you need to know
- The DART spacecraft will crash into an asteroid
- Test asteroid is not a threat to Earth
- The LICIACube spacecraft will follow DART to its final destination
NASA researchers have waited almost a year since SpaceX launched its Double Asteroid Redirection Test (DART) mission in November 2021 to see if a spacecraft can collide with a guinea pig asteroid to throw it off course.
The DART spacecraft, built and managed for NASA by the Johns Hopkins Applied Physics Laboratory, spent about 10 months on a one-way voyage to the small moon of the asteroid Didymos called Dimorphos, also considered an asteroid.
DART Spacecraft Specifications:
- DART without solar fields: 6.2 feet long × 5.9 feet wide × 8.5 feet high
- Solar systems: Each is 27.9 feet long
- Weight during impact: 1,260 pounds
- Impact speed: 3.8 miles per second
This artistic rendering shows the path the DART spacecraft will take before impacting the asteroid Dimorphos. (NASA)
Why Dimorphos?
The binary asteroid system consists only of Didymous, about half a mile in diameter, and the small moon (sometimes called the moonlet) Dimorphos, which is 525 feet in diameter and is the goal of this little experiment.
As the dynamic duo orbits the Sun, it can approach Earth from nearly half an AU to a distance of about 3 AU, which is just beyond the orbit of Mars.
(Not sure what an AU is? It stands for “astronomical unit,” and an AU is the same distance from the Sun to Earth, or about 93 million miles.)
At the time of impact, Dimorphos will be just 10.8 million kilometers from Earth, practically a walk around the block in space.
The impact is expected to occur at 7:14 p.m. EDT on Monday, September 26, as the DART spacecraft will be used as a battering ram as it accelerates nearly 4 miles per second when it hits Dimorphos.
This pair was chosen to determine how much impact the DART spacecraft will have on Dimorphos’ orbit once the cosmic collision occurs.
“Scientists believe the collision will change Dimorphos’ speed by a fraction of a percent. It should alter the small moon’s orbital period around the larger asteroid by several minutes — enough to be observed and measured by telescopes on Earth,” NASA said.
As the DART spacecraft (left) flies toward the moonless asteroid Dimorphos, it will be tracked by LICIACube, which will record the impact. (Italian Space Agency)
DART is not alone
How is DART’s historic moment captured? With a small travel companion, courtesy of the Italian Space Agency.
And it’s little: DART deployed a CubeSat on the shoebox side called Light Italian Cubesat for Imaging of Asteroids, or LICIACube for short.
This secondary spacecraft was deployed days ago and will record the collision caused by DART, study the formation and dissipation of the cloud that will result from the crash, and take measurements of the size of the crater that DART will leave in its wake, among other things, according to the Italian space agency.
And of course take photos.
In fact, DART has its own onboard camera called Didymos Reconnaissance and Asteroid Camera for Optical Navigation, or DRACO.
Not only will it help navigate DART to the binary asteroid system and measure the small moon’s shape and size, but it will stream images back to Earth ahead of the Galactic Fender-Bender, according to information from John Hopkins.
