By John Ikani
National Aeronautics and Space Administration (NASA) has launched a spacecraft on a mission to test technology that could one day tip a dangerous asteroid off course.
NASA’s Dart mission wants to see how difficult it would be to stop a huge space rock from colliding with Earth.
The $325m (£240m) Dart mission will target a pair of asteroids that closely orbit each other – known as a binary. The larger of the two objects, called Didymos, measures around 780m across, while its smaller companion – Dimorphos – is around 160m wide.
Impact should take place in the third quarter of 2022 when the binary asteroid system is 11 million kilometres (6.8 million miles) from Earth, almost the nearest point they ever get.
“What we’re trying to learn is how to deflect a threat,” NASA’s top scientist Thomas Zuburchen said of the $330m project, the first of its kind.
To be clear, the asteroids in question pose no threat to the planet. But they belong to a class of bodies known as Near-Earth Objects (NEOs), which approach within 48 million kilometres (30 million miles).
There are 10,000 known near-Earth asteroids that size or greater, but none has a significant chance of hitting in the next 100 years. One big caveat: scientists think there are still 15,000 more such objects waiting to be discovered.
Planetary scientist Essam Heggy said while the NASA mission sounds like science fiction, the threat to the planet is real if the fate of the dinosaurs 80 million years ago is recalled.
