#NewsBytesExplainer: How NASA will deflect asteroid by crashing DART spacecraft
How do we deal with an asteroid on course to hit the Earth? Well, one way is to change its direction. US space agency NASA's Double Asteroid Redirection Test (DART) mission plans to do exactly that. Launched in November last year, the project will use the "kinetic impactor" technique to deflect a near-Earth asteroid called Didymos and its orbiting moonlet Dimorphos.
A brief look at the DART mission
DART was launched on a SpaceX Falcon 9 rocket from the Vandenberg Space Force Base in California, US. It took off on November 24, 2021 and will impact Dimorphos on September 26 at 7:14 pm EDT (4:44 am IST, September 27). The $324.5 million project will be the first planetary defense mission to test asteroid deflection methods.
How will the deflection process work?
DART's targets are Didymos which is 780 meters wide and Dimorphos which measures only 160 meters across. Dimorphos orbits its parent asteroid Didymos every 12 hours. DART, which weighs nearly 500kg, will deliberately hit Dimorphos at a speed of 6.6km/s or 23,760km/h. The planned impact is expected to reduce Dimorphos's orbit and push it closer to Didymos.
What does the spacecraft pack?
DART comprises a 1-meter wide box with two roll-out solar arrays that give the spacecraft a width of roughly 12 meters. It packs a high-resolution camera for navigation called DRACO. It is similar to the one used on the New Horizons spacecraft.
How will we know if the asteroid has been deflected?
Roughly 10 days before the impact, a small probe called LICIACube, fitted with two cameras, will detach from DART and relay images to Earth. NASA will also use terrestrial telescopes to observe and measure the changes in the moonlet's orbit around Didymos. The European Space Agency will launch its Hera mission in 2024 to conduct post-impact investigations. It will reach the asteroids in 2026.
What is the significance of the DART mission?
We are witnessing a barrage of near-Earth encounters with asteroids this year, and over 35 of them went by the pale blue dot last month alone. Asteroids in general are harmless but can cause widespread destruction on impact. They are responsible for the extinction of dinosaurs. Thus, it makes sense to have a planetary defense system so that we don't suffer a similar fate.
