It’s been a month since the Double Asteroid Redirection Test (DART) mission launched on its way to the binary asteroid system of Didymos and Dimorphos. DART captured its first images three weeks ago, an important operational milestone as the spacecraft hurtles toward a collision with Dimorphos.
DART’s predetermined fate is to test a longstanding question of NASA’s: whether humankind can deflect an asteroid to stop it from hitting Earth. Neither Didymos nor the smaller Dimorphos threaten humanity, but they pass relatively close to Earth, making them a good testing ground. Better to see if we can change an asteroid’s path before we need to change an asteroid’s path.
Famously, it was an asteroid’s impact with Earth that doomed the dinosaurs to extinction. NASA tracks many objects in space that come close to Earth; they’re called Near Earth Objects (NEOs). None are currently on a collision course, and when you see headlines warning of such close calls, don’t worry: “close” in cosmic terms is usually not close at all. DART will collide with Dimorphos about 6.8 million miles from Earth in September 2022, if all goes according to plan.
The image above was taken when DART was about 2 million miles from Earth, using the spacecraft’s DRACO telescopic camera. It many look like only grainy blackness, but it captures about a dozen stars, according to a Johns Hopkins University press release. The imaged area is near where the constellations of Aries and Taurus intersect.
DRACO is the only instrument in DART’s payload, though DART is also carrying a small satellite that it will release 10 days before its arrival at the Didymos system. The camera took another image three days after the first, of Messier 38, a star cluster about 4,200 light-years from Earth.
As DART continues its trek toward its final destination, DRACO will take images along the way to help the DART team better understand any optical imperfections and calibrate brightness. That’s all useful information ahead of the last set of shots, which will be captured in about nine months.
Whether or not DART’s impact actually changes the Dimorphos’s orbital trajectory, the collision would demonstrate the ability for a spacecraft to autonomously navigate to and kinetically impact with a target asteroid. Hopefully, we won’t need a real-deal mission like this any time soon.