Things to know about DART – NASA’s new “Planetary Defence” – Erakina
For thousands of years, humans have been making defence against other humans. But now the times have changed mankind faces a bigger threat that doesn’t reside on earth but comes from outer space Asteroids.
NASA is all set to crash a spacecraft travelling at the speed of 6.6 Km/s (24,000kph) into an asteroid next year. Although Asteroid doesn’t impose any immediate threat to earth, DART mission is to determine whether it’s an effective way to tackle any future encounters with large asteroids.
What is DART?
Double asteroid redirect or DART is a planetary defence test initiated by NASA in which a spacecraft is set to collide with an asteroid to alter its trajectory. In turn assuring that if In future there happens to be an encounter with an asteroid heading toward us, its course could be changed. When DART smashes the asteroid the kinetic energy from the spacecraft get transferred and asteroids trajectory is said to be altered, it is also the first kinetic impactor.
DART space shuttle is equip with Roll Our Solar Arrays (ROSA) to provide the required solar energy for electric propulsion.
[DART team members carefully lower the DART spacecraft onto a low dolly in SpaceX’s payload processing facility on Vandenberg Space Force Base.]
Credits: NASA/Johns Hopkins APL/Ed Whitman
DART’s total budget is $313.9 million over a span of 8 years. When DART smashes the asteroid the kinetic energy from the spacecraft will get transferred and its trajectory is said to be altered, it is also the first kinetic impactor.
DART will be made and managed in Johns Hopkins Applied Physics Laboratory. The spacecraft weights approximate 1,210 and it’s diameter is 780 meters where as the targeted asteroid is 160 meters in size.
Date of the mission:
DART is all set to be launched on a SpaceX Falcon 9 rocket and the launch is scheduled for 24 November 2021 and the impact is scheduled for between September 26, 2022, to October 1, 2022.
Dimorphous is chosen as the target for the impact. Dimorphous is a small asteroid to which NASA refers as the “moonlet” it revolves around Didymos which is the larger companion asteroid. The name is derived from the Greek word “Dimorphous” which means “Two forms”
NASA has emphasized the selected target asteroid do not pose any threat to earth and the whole purpose of this mission is to demonstrate and this asteroid is specifically selected because of the ability to observe it from the ground-based facility.
Significant of this mission
DART will help scientist calculate the required momentum of impact needed to deflect an asteroid if one is headed towards the earth in the future. It’ll also help the scientist understand on the composition of the asteroid as it’s still uncertain how porous the asteroid is.
What are the dangers posed by these asteroids?
More than 100 such space rocks penetrate the earth’s atmosphere and are burned up and turned into dust before hitting the earth surface, Smaller space rocks do not do any harm to the earth surface.
NASA states that “Every 2,000 years or so a meteoroid the size of a football field hits the earth and causes significant damage to the area”
NASA also clarifies if anything bigger than 1 to 2 km could have a worldwide effect. Less than 5 per cent of the original object make it to the earth surface but if a significantly larger object tends to break through the earth’s atmosphere it would have a comparatively greater impact.
DART – Our Ultimate Defence?
NASA has found around 19,000 near-earth asteroids with half of them being larger than 140 meters in size which can have a significant effect on the area of impact.
Anything bigger than this will have a sub-global effect. As for now, there are no known asteroids that poses threat to earth for 100 years to come.
DART’s coordination lead at Johns Hopkins Applied Physics Laboratory, Nancy Chabot states that “you’d want to do this technique many years in advance, decades in advance” if it can be reliably found out that an asteroid was coming to hit Earth.
“You would just give this asteroid a small nudge, which would add up to a big change in its future position, and then the asteroid and the Earth wouldn’t be on the collision course,” she added.
–By Shivam bhamre