A spacecraft deliberately built by NASA is set to collide with a small asteroid as part of a planetary protection test mission.
While this asteroid – called Dimorphos – poses no threat to Earth, the goal of the mission is to demonstrate that incoming dangerous rocks can be deflected by deliberately colliding with them.
The spacecraft, known as the Double Asteroid Redirection Test (DART), is expected to collide with the 170-meter (560-foot) asteroid at 00:14 UK time on September 27.
Dimorphos is part of a binary system of asteroids and orbits Didymos, which takes about 11 hours and 55 minutes.
But NASA astronomers hope that, while self-destructing in the process, DART will shorten this orbital period by about 10 minutes.
NASA said, “Dart’s target asteroid is not a threat to Earth but is an ideal testing ground to see if this method of asteroid deflection – known as kinetic impact technology – would be a viable way to protect our planet in the event of an asteroid collision. Of course with Earth it is discovered in the future.”
There are currently somewhere around 27,000 asteroids in near-Earth orbit.
Rocks 140 meters (460 ft) in size and larger and approaching 4.7 million miles (7.5 million km) during orbit are classified as hazardous asteroids (PHAs).
The Dart mission will be the first-ever comprehensive demonstration of asteroid deflection technology.
The spacecraft recently took its first images of Didymos and Demorphos using an onboard instrument known as the Didymos Reconnaissance Camera and the Asteroid Camera for Optical Navigation (Draco).
It was about 20 million miles (32 million kilometers) from the asteroid system when the images were taken in July.
It took 10 months for Dart to get close to Dimorphous after its launch last November on a SpaceX Falcon 9 rocket.
The asteroids will be about 6.8 million miles (11 million kilometers) from Earth when the collision occurs.
release Tweet embed Falcon 9 carries the DART spacecraft – begins a nearly year-long journey to crash into a distant asteroid as a test! Keep checking back for more photos! #DARTMission #PlanetaryDefense more: pic.twitter.com/qJmffF2wIo
– NASA HQ PHOTO (nasahqphoto) November 24, 2021
The Dart will accelerate at about 15,000 mph (24,140 kph) before colliding with Demorphos.
This collision will be recorded by a briefcase-sized satellite known as the Light Italian CubeSat Asteroid Imaging Satellite (LICIACube), provided by the Italian Space Agency.
LICIACube, which weighs just 14 kg (31 lb), took a trip with Dart into deep space before recently detaching from the spacecraft in a final farewell.
In 2024, the European Space Agency (ESA) will launch its Hera spacecraft, which will go on a two-year journey to the asteroid system to gather information in the aftermath of the accident.
“By the time Hera reaches Didymos, in 2026, Demorphos will have achieved historical significance: the first object in the Solar System whose orbit has been transformed by human effort in a measurable way,” the European Space Agency said.