Why Nasa Wants To Slam a Spacecraft Into An Asteroid

New Delhi: The idea has always fascinated science fiction writers and Hollywood: an asteroid colliding with our planet causing mass extinction. Now, Nasa wants to stay prepared for “Deep Impact”, just in case an asteroid is headed our way.

About a week from now, on November 23, Nasa is scheduled to launch the Double Asteroid Redirection Test (Dart).

In a test of planetary defence, the space agency plans to slam Dart with the asteroid Dimorphos and change its orbit, a programme that aims to test technology designed to deflect an asteroid on a collision course with Earth in future.

Currently, no asteroid or comet poses a threat to Earth and Dart is just an experiment to test our capabilities in the event such a threat arises in future.

After travelling for almost a year, Dart will collide with Dimorphos at a speed of 24,000 kmph, some 6.8 million miles from Earth between September 26 and October 1 next year, changing the asteroid’s velocity and orbit.

“Although there isn’t a currently known asteroid that’s on an impact course with the Earth, we do know that there is a large population of near-Earth asteroids out there,” said Lindley Johnson, Nasa’s Planetary Defence Officer, reported various media outlets.

“The key to planetary defence is finding them well before they are an impact threat,” Johnson said. “We don’t want to be in a situation where an asteroid is headed towards Earth and then have to test this capability.”

Dimorphos, which means “two forms” in Greek, is about the size of the Great Pyramid of Giza and orbits around the asteroid Didymos, “twin” in Greek, once every 11 hours 55 minutes.

Dimorphos is the most common type of asteroid and is about 4.5 billion years old. The near-Earth asteroid was originally discovered in 1996 by Joe Montani of the Spacewatch Project at the University of Arizona.

More than 27,000 near-Earth asteroids have been identified but none currently pose a danger to the planet.

Dart is part of a larger, two-part mission called the Asteroid Impact and Deflection Assessment (Aida) mission. The second part is the European Space Agency’s Hera mission. Scheduled for launch in October 2024, Hera will study the aftermath of the collision.

Dart will be launched from Vandenberg space force base, California, on a SpaceX Falcon 9 rocket.