Sixty-five million years ago, an asteroid collided with Earth and killed two-thirds of life on the planet, ending the reign of the dinosaurs. Today, scientists from NASA and European space agencies seek to prevent future asteroids from threatening humans.
“The threat from asteroids is real,” NASA scientist Elena Adams said during a June 28 roundtable on international cooperation for planetary defense. Adams is the systems engineer for the first planetary defense mission, known as Double Asteroid Redirection Test (DART). The DART mission is a collaboration between NASA, the European Space Agency (ESA) and the Italian Space Agency.
Nasa launched the DART mission on November 24, 2021, and the spacecraft is due to crash into Dimorphos, a small asteroid (160 meters in diameter) in the Didymos asteroid system, on September 26. “Our goal is to go and crash into an asteroid” and alter its trajectory, Adams told the event hosted by the US State Department.
The panel, which was greeted with opening remarks by the Department of State’s Principal Deputy Assistant Secretary for the Bureau of Oceans and International Environmental and Scientific Affairs Jennifer Littlejohn, was convened in advance of the Day United Nations Asteroids International, June 30. The date commemorates the anniversary of the Tunguska event, in which an asteroid struck Earth’s atmosphere above eastern Siberia on this day in 1908. The asteroid – about 50 to 80 meters in diameter – has unleashed a force that flattened 80 million trees, destroying more than 2,000 square kilometers of forest.
Panelist Thomas Jones, chairman of the Association of Space Explorers’ Committee on Near-Earth Objects and a former astronaut, said the 1908 Tunguska disaster shows why space agencies, governments and scientists around the world should strive prevent asteroids from hitting Earth in the future. “We have a chance to prevent a natural disaster from happening using our cooperative skills across the planet,” he said.
Jones and other panelists said that by successfully altering the trajectory of Dimorphos – which is not on a collision course with Earth – the DART mission would show that the international community is capable of defending itself against future asteroids that could threaten the Earth.
Equipped with a fully autonomous navigation system, the DART satellite will reach Dimorphos traveling at 6.6 kilometers per second. Prior to impact, DART will launch the Italian Space Agency’s small satellite, called the Light Italian CubeSat for Imaging of Asteroids (LICIACube), to monitor the collision and measure DART’s effect on the asteroid.
Astronomers and scientists around the world will also be monitoring changes in the asteroid’s trajectory, and in October 2024 the European Space Agency will launch the HERA mission to encounter Dimorphos and examine the effects of the DART impact.
“This is really a momentous mission, because it’s really the first step in understanding how we can actually deflect an asteroid,” said Ettore Perozzi, of the Italian Space Agency’s Space Situational Awareness Office.
Or, as Adams put it, “We’re coming back for our friends, the dinosaurs.”