“This is the first time we’ve really tried to move something in our solar system to prevent [potential] Natural disasters have been part of our planet’s history from the beginning,” Statler said.
DART probe, short for Double Asteroid Redirection Test, which has been in use since 2015.It was designed, built, and operated by Johns Hopkins University’s Applied Physics Laboratory and supported by a number of NASA centers, and Launched last November. DART is an important part of AIDA (Asteroid Impact and Deflection Assessment), a collaborative project between NASA and the European Space Agency. The mission also relies on observatories in Arizona, New Mexico, Chile and elsewhere; astronomers focused their telescopes on Dimorphos and Didymos to measure the post-impact deflection as precisely as possible.
Until the final moments of DART’s flight, astronomers could only see Dimorphos and Didymos as a blip. The smaller asteroid is so small that it can’t be seen from Earth-based telescopes — but astronomers can measure the already dim light it emits from its larger sibling as it orbits it frequency to track it.
The spacecraft’s final approach was captured by its optical camera called the DRACO, which is similar to the one on the ship new horizons, which flew past Pluto. Even this closer camera could only see Dimorphos as a separate object a few hours before impact.
“Because you’re coming so fast, it’s only in the last few minutes that we get to see what Dimorphos looks like: What is the shape of this asteroid we’ve never seen before?” Johns Hopkins planetary scientist and DART The head of coordination, Nancy Chabot, said in an interview days before the impact. “It’s actually only in the last 30 seconds that we can resolve the surface features of the asteroid.”
In fact, to this day, scientists aren’t sure if the asteroid is more like a billiard ball or a dust ball. “Is this moon a giant rock, or a pile of pebbles or grains? We don’t know,” JHU researcher and DRACO instrument scientist Carolyn Ernst said before the impact. Its makeup could affect many variables that scientists want to study: how much the impact would alter the asteroid’s trajectory, whether it would leave a crater, spin the asteroid or eject rocky debris.
Unlike most space probes, DART didn’t slow down before reaching its target. As it approaches, its cameras keep taking images of asteroids growing in the frame and sending them to Earth via the Deep Space Network, an international antenna system managed by NASA’s Jet Propulsion Laboratory.
These images are not only important for research; they are key to navigation. It takes 38 seconds for the human operator to send the signal to the DART or the probe to send the image back to Earth. When timing is critical, it is necessary for the probe to steer itself. Over the past 20 minutes, its SMART Nav automation system has made a “precise lock” on the target and used those images to adjust the spacecraft’s heading via the thruster engines.