Dart: What Is It?

Today I learnt about the recent space launch of DART and its significance.

DART stands for "Double Asteroid Redirection Test". This is the world's first full scale mission to test technology for defending earth against potentially hazardous asteroids or comets.

Who's launching this spacecraft?

NASA has launched the spacecraft using one of SpaceX's Falcon 9 rockets. DART was launched on November 24th, 2021 and the impact is planned to happen on September 22nd, 2022 (after a year of cruising through space.)

What asteroid will DART destroy?

The binary near-earth asteroid Didymos is the target for the DART test. While the primary body of this asteroid is fairly big having a diameter of 780m, it's secondary body (moonlet) is significantly smaller with a diameter of about 160m. This is the size of asteroids that we have to worry about when thinking about our planet. DART will crash a space probe into this moonlet and hopefully, the kinetic energy (6.6km/s) of the spacecraft impact will be successful in deflecting an asteroid on a collision course with earth.

"Dart will only be changing the period of the orbit of the asteroid by a tiny amount. And really that's all that's needed in the event that an asteroid is discovered well ahead of time," said Kelly Fast, from Nasa's planetary defense co-ordination office.

This collision will change the speed of the asteroid by a fraction of a millimeter per second... it's orbit will alter around Didymos. It's an incredibly small shift, but more than enough to knock an asteroid off a collision course with earth.

Above is a picture of the DART team transferring the spacecraft from it's shipping container.