NASA controllers will deliberately crash their $330 million spacecraft traveling at more than four miles per second into Dimorphos, an asteroid, in a few weeks, so as to destroy it.
The purpose of this kamikaze science mission is for space engineers to learn how to deflect asteroids in case one is ever discovered on a collision course with Earth.
NASA says that the impact of its mission spacecraft, Double Asteroid Redirection Test (DART), on Dimorphos’ orbit will provide crucial data about how well spacecraft can protect Earth from asteroid armageddon.
Professor Alan Fitzsimmons, an astronomer at Queen’s University Belfast said that is known that “asteroids have hit us in the past…these impacts are a natural process and they are going to happen in the future. We would like to stop the worst of them.”
As a member of the science team for the DART mission, Fitzsimmons said, “The problem is that we have never tested the technology which will be needed to do that. That is the purpose of DART.”
The half-ton probe is set to strike its target in the early hours of September 27th so that scientists may carefully study the asteroid’s path following the collision. This will allow them to better understand how similar collisions might deflect Earth-bound asteroids and comets.
Jay Tate, the director of the National Near Earth Objects Information Centre in Knighton, said, “DART’s target has been carefully chosen.”
“Dimorphos actually orbits another bigger asteroid called Didymos, and the extent of the deflection caused by the crash will be easier to detect as astronomers have been carefully observing its path around the bigger asteroid,” he added.
Effects of asteroids and comets on Earth considered
In the past, asteroids and comets have had huge impacts on life on Earth with the best-known collision occurring sixty-six million years ago when a ten-kilometer-wide asteroid struck Chicxulub in the Yucatán Peninsula in Mexico.
The impact of the collision created a blast that had the energy of several billion atomic bombs and led to the destruction of seventy-five percent of all plant and animal species, including all land-based dinosaurs.
Films, such as Don’t Look Up, Armageddon, and Deep Impact, have depicted similar devastation being triggered by asteroid or comet crashes in modern times.
Astronomers, however, believe it is unlikely we will experience such catastrophic impacts in real life in the near future.
Fitzsimmons said, “We know where the big asteroids are because we can see them with our current generation of telescopes, and we know none of the detected asteroids are coming anywhere near our planet for the next couple of hundred years or so.”
“So, we can rest easy in our beds about those ones,” Fitzsimmons added although he identified many smaller ones have yet to be detected, and they are still big enough to destroy entire cities and devastate large areas.
He assured that: “We are mapping these smaller objects with increasing accuracy, but we will have to be prepared to act if we find one that is on course for Earth. DART is the first step in ensuring we have the right technology to deal with the threat.”
Relevance of NASA’s DART in crashing spacecraft
NASA’s planetary defense officer, Lindley Johnson, backed the initiative of developing asteroid deflection technology, stressing that it is required as soon as possible.
“We don’t want to be in a situation where an asteroid is headed toward Earth and then have to be testing this kind of capability,” Lindley Johnson said.
Small asteroids and comets pose a danger such as that provided by the rocky object that penetrated Earth’s atmosphere near the Russian city of Chelyabinsk on February 15, 2013.
The object exploded in the atmosphere, triggering a four hundred-kiloton blast that injured more than 1,500 people. It was thought to have been twenty meters in diameter.
Jay Tate said, “Had that object entered the atmosphere a mere 20 km further north than it did, it would have done much greater damage to the city.”
He further noted that “we have been very lucky not to have [had] substantial casualties from these things within living memory. We have to be aware that they will happen one day, and be ready to do something about them.”
DART’s asteroid images a basis for deflecting asteroids or comets
DART’s target, Dimorphos, is 160 meters in diameter and orbits its parent asteroid every twelve hours, implying that ten days before impact, the spacecraft will release a purse-sized, Italian-built probe called LiciaCube.
The probe is fitted with two cameras that have been given the Star Wars inspired names of Luke and Leia. Therefore, images of DART’s asteroid impact will be recorded by Luke and Leia and beamed back to ground controllers.
Earth-based telescopes will then study the asteroid and identify how its orbit has changed. “That way, we will get an idea [about] how easy it is going to be to deflect incoming asteroids or comets,” said Tate.
Fitzsimmons also said, “Hitting Dimorphos is not going to be easy…it is only 160 [meters] in diameter and the spacecraft will be traveling at four miles a second. Hitting the asteroid dead [center]—where the crash will have the most effect—will push DART’s autonomous navigation devices to their limit.”
He further noted that NASA engineers and scientists have done an incredible job and are confident in this working. However, you never really know until it is attempted.
In conclusion, the European Space Agency is set to send a robot spacecraft, Hera, to Dimorphos in 2024 to study the crater left by DART to analyze its collision with the asteroid.