Double Asteroid Redirection Test(DART) is a planetary defence mission to aim to save earth from asteroid impact by changing its momentum.DART mission follow the principles of kinetic impact and change momentum of an asteroid.It is conducted by world's most advanced space organization NASA with the help of John Hopkins University's applied physics laboratory.On 26 September 2022,DART spacecraft successfully collided to the Dimorphos asteriod and Scientists are studying the impact and results, which will come to media in a weeks.
History
NASA and European space agency (ESA) combined to form Asteroid Impact Deflection Assessment (AIDA) in 2015.AIDA working on the Asteroid deflection startegies .For this ESA has a mission called AIM to study composition of asteroid, strength, surface,internal structure, effect.Then NASA's DART mission will kinetically impact on asteroid to change its momentum by accuracy.DART mission was launched on 24 November 2021 by SpaceX's Falcon-9 rocket.The mission was funded by NASA's Planetary Defence Coordination Office and controlled by John Hopkins laboratory.It has international partners like ESA,ASI,JAXA.It successfully completed its mission on 26 September 2022.
Didymos system
NASA chossed an asteroid system called Didymos binary system,which was named after an asteroid Didymos.The system consists of an asteroid Didymos and its minor moon called Dimorphos.The mission was decided to hit to entire system first,but then Dimorphos only was chossed to hit.This system is not an earth crossing asteroid that means it doesn't threat to earth.It was at a distance of 11 million km from earth in 2022 (placed in between mars and Jupiter).The mass of Dimorphos is about 4.8 billion kg where Didymos has a mass of 528 billion kg . Diameter of Didymos is 780m and Dimorphos has a diameter of 160m.Dimorphos is orbited around its planet Didymos at a distance of 1km(0.62 mile). Clearly,Didymos is much heavier than its moon Dimorphos.So,NASA took descision to hit the moon only for its low mass.Why this system?
- Didymos system is located relatively close to earth.So time taken is minised.
- The size of the dimorphos asteroid is small and average size of all the asteroids have threat to earth.
- The Main reason is impact and effect of asteroid doesn't affect our planet.
Effect of asteroid impact
The dart impacter hit the dimorphos in opposite direction of its orbital velocity and it is expected to change the velocity as well as its radius of orbit around didymos.The time period would expected to reduce.
Due to effect of recoil momentum and ejecta ,it would expected for change the trajectory of didymos too.All the effects and measurable changes have been calcuting by scientists.Images have been coming by LICIAcube satelite of Itali.