It’s a test of deflection technology that could one day be used to protect Earth if a space rock is determined to have an impact trajectory with our planet. Currently, there are no asteroids (including Didymos and Dimorphos) expected to hit our world.
Here’s what to expect good the day of the event
The DART spacecraft is carrying an imager called DRACO, the Didymos Reconnaissance and Asteroid Camera for Optical Navigation, and will share a live stream of images as it approaches the double asteroid system. These images will be shared at a speed of one per second, offering viewers a video-like experience.
What starts out as the Pixel 1 will eventually become an incredibly detailed look at Dimorphos before the DARTs get involved.
Humans have never seen Dimorphos before because the asteroid system appears as a single point of light in ground-based telescopes.
In the last hour of the approach, Dimorphos and Didymos will be seen. Pins of light will sharpen, revealing the two separate heavens the bodies Scientists will finally be able to determine the shape of Dimorphos, as well as whether its surface is rough or smooth.
“Our final image will probably be about two and a half seconds before impact, so the DRACO field of view will be completely filled with this beautiful image of Dimorphos,” said Elena Adams, DART mission systems engineer. Johns Hopkins University Applied Physics Laboratory in Laurel, Maryland.
During the show, expect to hear that the team has lost radio contact with DART. They will continue to take images and display them for about eight seconds as they travel through space to Earth, said Edward Reynolds, DART project manager at the Applied Physics Lab.
Also on the trip is the Italian Space Agency’s Light Italian CubeSat for Imaging of Asteroids, or LICIACube. This briefcase-sized CubeSat carried DART into space and was launched from the spacecraft on 9/11.
There are two cameras on the CubeSat called LUKE (LICIACube Unit Key Explorer) and LEIA (LICIACube Explorer Imaging for Asteroids). Together, they will collect images and help guide LICIACube on its journey.
The small satellite travels at a safe distance to record what happens behind the DART.
Three minutes after impact, LICIACube will fly past Dimorphos to capture images and video of the impact plume as it ejects from the asteroid and possibly spy on the crater it may leave behind. The mini-satellite will also see the opposite hemisphere of Dimorphos, which DART will not see until it is obliterated.
The CubeSat will turn to keep its cameras pointed at Dimorphos as it flies. Days, weeks and months later, we will see the images and videos taken by the Italian satellite
t who saw the collision event.
The first images expected back from LICIACube can show the moment of impact and the resulting plume.
While the engineering team hopes to celebrate the successful impact, astronomers will know it’s time to get to work, said Tom Statler, NASA’s DART program scientist. Ground-based observatories around the world will observe the asteroid system as a way to confirm whether DART has successfully altered the asteroid’s motion.
The effects will also be observed by the James Webb Space Telescope, the Hubble Space Telescope and NASA’s Lucy mission. The collected images can show the overall brightness of the entire asteroid system, indicating how much dust and debris the impact has created, Statler said.
Astronomers will use ground-based telescopes to compare previous observations of the system with those collected after the event.
Today, Dimorphos takes 11 hours and 55 minutes to complete an orbit around Didymos. After DART’s impact, that could be reduced by 10 minutes — something that can be measured by ground-based telescopes — and ultimately show whether DART was successful.
And don’t expect to see the last of this asteroid system until 2022.
To study the effects of the impact, the European Space Agency’s Hera mission will be launched in 2024, and we can expect even more dramatic images then.
The spacecraft, along with two CubeSats, will arrive in the asteroid system in 2026, about four years after DART ends its mission. There, Hera will study the two asteroids, measure the physical properties of Dimorphos, and study the DART impact crater and the moon’s orbit, with the overall goal of establishing an effective planetary defense strategy.