A flaming asteroid, yesterday

Nasa prepares to intentionally crash spacecraft into a small asteroid

Image credit: Science Photo Library

The spacecraft, known as Double Asteroid Redirection Test (Dart), is expected to collide with a 170-metre wide steroid named Dimorphos at 12:14am UK time on 27 September.

A spacecraft built by Nasa is set to intentionally smash into a small asteroid as part of a planetary protection test mission, to help prove that this could be an effective way of deflecting dangerous incoming rocks.

The chosen asteroid, named Dimorphos, orbits Didymos in around 11 hours and 55 minutes, but Nasa astronomers hope that Dart will destroy itself and cut about 10 minutes off this time. The collision is expected to take place at about 6.8 million miles from Earth.  

"Dart's target asteroid is not a threat to Earth but is the perfect testing ground to see if this method of asteroid deflection - known as the kinetic impactor technique - would be a viable way to protect our planet if an asteroid on a collision course with Earth were discovered in the future," a Nasa spokesperson said. 

The mission has been designed to operate fully autonomously, to avoid putting human lives at risk. 

It will be the first full-scale demonstration of asteroid deflection technology and will be recorded by an Italian Space Agency satellite called the Light Italian CubeSat for Imaging of Asteroids. The collision has been scheduled for the early hours of 27 September 2022. 

Currently, there are an estimated 27,000 asteroids in near-Earth orbit. These often vary in size, but some can be as large as 140 metres (460ft) or larger, and come as near as 4.7 million miles (7.5 million km) during orbit. These are classed as potentially hazardous asteroids (PHAs).

The Dart mission will be the first-ever full-scale demonstration of asteroid deflection technology.

The spacecraft recently captured its first images of Didymos and Dimorphos in July, using an onboard instrument, known as the Didymos Reconnaissance and Asteroid Camera for Optical navigation (Draco). At the time, Dart was located about 20 million miles (32 million km) away from the asteroid system. It has taken the spacecraft 10 months to come close to its target. 

Dart will go at speeds of about 15,000 miles per hour before colliding with Dimorphos. Once Dart has been destroyed, ground-based space telescopes will evaluate Didymos and Dimorphos to see just how much the orbit has changed. However, scientists down on Earth will have to wait years to learn about the details of the mission. 

In 2024, the European Space Agency (ESA) is scheduled to launch the Hera spacecraft, which will go on a two-year journey to the asteroid system to gather information in the aftermath of the crash.

"By the time Hera reaches Didymos, in 2026, Dimorphos will have achieved historic significance: the first object in the Solar System to have its orbit shifted by human effort in a measurable way," ESA said. 

Asteroid strikes have played a major role in  the Earth's history. The mass extinction that brought about the end of the dinosaurs some 66 million years ago was caused by a miles-wide (10-15km) asteroid that slammed into modern-day Mexico. It’s been theorised that asteroids brought water to planet Earth and even the basic organisms which led to life as we know it.

Last May, the Asteroid Mining Corporation (AMC) in partnership with Tohoku University in Japan, presented Scar-e, a six-legged robot capable of gripping onto an asteroid in space to stop it from floating away and drilling it to obtain iron, nickel and platinum. If successful, the technology could help solve the global shortage of precious metals.

Sign up to the E&T News e-mail to get great stories like this delivered to your inbox every day.

Recent articles