NASA’s Double Asteroid Redirection Test (DART) spacecraft is finally within sight of its target. In 17 days, the probe will crash head-on into Dimorphos, a natural satellite of the asteroid of Didymos.
The plan to smash a spacecraft into a binary asteroid system is part of an effort to shore up our planetary defence capabilities. DART, launched in November 2021, will test how humanity could redirect an asteroid in case we spot one on a collision course with Earth. NASA said this week that the DART team was finally able to see the light reflecting off the asteroid Didymos after combining 243 images taken by DART’s high-resolution imager, called the Didymos Reconnaissance and Asteroid Camera for Optical navigation (DRACO).
“This first set of images is being used as a test to prove our imaging techniques,” said Elena Adams in a NASA release. Adams is the DART mission systems engineer at Johns Hopkins Applied Physics Laboratory. “The quality of the image is similar to what we could obtain from ground-based telescopes, but it is important to show that DRACO is working properly and can see its target to make any adjustments needed before we begin using the images to guide the spacecraft into the asteroid autonomously.”
DRACO’s images will help the DART team optimise the software and navigation systems that are guiding the craft toward the asteroid system. While this image has confirmed that Didymos is in DART’s view, the craft will be impacting Dimorphos — a satellite asteroid of Didymos sometimes referred to as a minor-planet moon. NASA is aiming to crash DART head-on into Dimorphos on September 26, and scientists will be looking for data on how the impact altered the asteroid’s trajectory, by measuring the change in Dimorphos’ orbit around Didymos.
Let’s be clear: This is just an experiment. NASA says Didymos and Dimorphos do not pose a threat to Earth, and the energy transferred through DART’s impact is low enough to prevent knocking them into an Earth-bound trajectory.