In a few weeks, NASA controllers will deliberately crash their $330 million Dart robotic spacecraft into an asteroid. The half-ton probe will travel at more than 4 mph when it hits its target, Dimorphos, and will be destroyed.
The purpose of this kamikaze science mission is simple: space engineers want to learn how to deflect asteroids in case they are discovered during a collision with Earth. Observations of Dart’s impact on Dimorphos’ orbit will provide key data on how the spacecraft could protect Earth from asteroid doomsday, they said.
“We know asteroids have hit us in the past,” said astronomer Professor Alan Fitzsimmons from Queen’s University Belfast. “These effects are a natural process and they will happen in the future. We want to prevent the worst of them.
“The problem is we’ve never tested the technology needed to do this. That’s what Dart is for,” said Fitzsimmons, a science team member on the Double Asteroid Redirection Test (Dart) mission. The probe, launched in November last year, is scheduled to hit its target in the early hours of September 27 BST. By carefully studying the paths of asteroids after collisions, scientists believe they will better understand how similar collisions can be used to deflect asteroids and comets on Earth.
“Dart’s targets were carefully selected,” said Jay Tate, director of the National Center for Near-Earth Object Information in Boyce Knighton. “Dimorphos actually orbits another, larger asteroid, Didymos, and since astronomers have been closely watching its path around the larger asteroid, the degree of deflection caused by the crash will be easier to detect.”
In the past, asteroid and comet impacts have had a major impact on life on Earth. The most famous collision occurred 66 million years ago, when a 10-kilometer-wide asteroid struck Chicxulub on Mexico’s Yucatan Peninsula. The energy of the explosion from the collision was equivalent to billions of atomic bombs and caused the destruction of 75% of plant and animal species, including all land-dwelling dinosaurs.
Since then, films such as Don’t look up, the end of the world and Deep impression Similar devastation caused by a crashed asteroid or comet in modern times is depicted. However, astronomers believe that we are unlikely to experience such catastrophic effects in real life in the near future.
“We know where the large asteroids are because we can see them with our current generation of telescopes, and we know that none of the detected asteroids will come close to our planet for the next few hundred years or so. . . So we can sit back and relax in bed,” Fitzsimmons added.
“However, many smaller objects have yet to be discovered, and they are still large enough to destroy entire cities and large areas. We are mapping these smaller objects with increasing precision, but if we find one that is in Earth orbit object, we will have to prepare for action. Dart is the first step in making sure we have the right technology to deal with the threat.”
This was supported by Lindley Johnson, NASA’s planetary defense officer, who emphasized the importance of developing asteroid deflection technology as soon as possible. “We don’t want asteroids to fly towards Earth and then have to test that capability.”
A rocky object penetrating Earth’s atmosphere near the Russian city of Chelyabinsk on February 15, 2013 provides an example of the danger posed by small asteroids and comets. Thought to be 20 meters in diameter, it exploded in the atmosphere, triggering a 400-kiloton explosion that injured more than 1,500 people.
“If that object entered the atmosphere 20 kilometers further north than it did, it would have done more damage to the city,” Tate said. “We were fortunate not to have major casualties among these things that are remembered. We have to realize that they will happen one day and be ready to do something about them.”
Dart’s target Dimorphos is 160 meters in diameter and orbits its parent asteroid every 12 hours.Ten days before impact, the spacecraft will release a wallet-sized, Italian-made probe called LiciaCub equipped with two cameras star wars-Inspired by the names Luke and Leia. Images of the Dart asteroid impact will be recorded by Luke and Leia and transmitted back to ground controllers.
Then, telescopes on Earth will study the asteroid and determine how its orbit has changed. “That way, we’ll know how easy it is to deflect an incoming asteroid or comet,” Tate said.
In addition, the European Space Agency will send the robotic spacecraft Hera to Dimorphos in 2024 to study the crater left by Dart and analyze its collision with the asteroid.
“It’s not easy to hit Dimorphos,” Fitzsimmons said. “It’s only 160 meters in diameter, and the spacecraft will travel at 4 miles per second. Impacting the asteroid dead center — where the impact of the crash is greatest — will push Dart’s autonomous navigation equipment to its limits.
“NASA engineers and scientists have done tremendous work and believe it will absolutely work. But you never really know until you’re done,” Fitzsimmons said.