It was a plan more like a blockbuster movie script: to crash a spacecraft into an asteroid to throw the space rock off course.
Remarkably, NASA’s Double Asteroid Redirection Test (DART) actually had a Hollywood ending, as new research confirms the mission was a resounding success.
The US Space Agency’s refrigerator-sized satellite managed to skim 33 minutes off the orbit of a 160-meter-wide asteroid known as Dimorphos when it rocketed into it at 14,000 mph last September.
That is almost five times more than predicted.
Dimorphos orbits a much larger 780-meter-wide object called Didymos, located 6.8 million miles from Earth.
Good luck! NASA’s Double Asteroid Redirection Test (DART) actually had a Hollywood ending, as a new study has confirmed the blockbuster movie script mission was a resounding success
Before impact, the moonlet Dimorphos took 11 hours and 55 minutes to complete one circuit of its sibling, but now it takes 11 hours and 22 minutes.
“The change in its orbit was greater than what many of us, including myself, had expected,” said DART mission leader Andrew Cheng of the Johns Hopkins University Applied Physics Laboratory in Maryland.
WHAT WAS DART?
DART was the world’s first planetary defense test mission.
It involved a spacecraft crashing into the small lunar asteroid Dimorphos, which orbits a larger companion asteroid called Didymos.
This was done to slightly alter Dimorphos’ orbit.
The moon has a diameter of about 165 meters and although it poses no threat to Earth, NASA wanted to measure the asteroid’s changed trajectory as a result of the collision.
Post-impact observations from Earth-based optical telescopes and planetary radars measured the change in Dimorphos’ orbit around Didymos.
Before the collision, the time it took the moonlet to complete one circuit of its sibling was 11 hours and 55 minutes, but now it takes 11 hours and 22 minutes.
This demonstration of planetary defense will inform future missions that could one day save Earth from a deadly asteroid impact.
“The kinetic impact of the DART was very effective in deflecting the asteroid Dimorphos.”
Researchers say understanding how DART’s impact changed the moon’s orbit sheds light on how this approach could provide a defense system against potential collisions between space rocks and Earth.
Estimates of how much Dimorphos’ momentum has changed are revealed in five new scientific papers, all published in Nature.
Cristina Thomas and her colleagues at Northern Arizona University determined that Dimorphos’ orbital period had shortened by about 33 minutes, while experts from the Johns Hopkins University Applied Physics Laboratory tried to reconstruct the impact.
They also described in detail the location of the impact site, which showed that it was between two boulders, one of which was scraped by the spacecraft when it made contact with the moon.
DART was launched in November 2021 with the aim of knocking a space rock off course as part of an experiment in planetary protection.
It was the world’s first test of a kinetic impact mitigation technique, using a spacecraft to deflect an asteroid that poses no threat to Earth and adjust the object’s trajectory.
At 19:14 ET on September 26 of last year, DART intentionally crashed into Dimorphos, the asteroid moonlet in the double asteroid system of Didymos.
Two days after DART’s collision, astronomers Teddy Kareta and Matthew Knight captured the massive plume of dust and debris that had blown up from the asteroid’s surface with the SOAR telescope at NSF’s NOIRLAb’s Cerro Tololo Inter-American Observatory.
Jian-Yang Li and colleagues at the Planetary Science Institute in Tucson analyzed observations of this ejecta plume captured by the Hubble Space Telescope.
They said the speed at which this debris was ejected may help explain the momentum change caused by the impact.
The Double Asteroid Redirection Test was launched last November ahead of a year-long journey to collapse on the small asteroid Dimorphos, orbiting a larger one called Didymos.
A space rock the size of Dimorphos (pictured) could cause continent-wide destruction on Earth, while the impact of one the size of the larger Didymos would be felt globally
Separate researchers at the Johns Hopkins University Applied Physics Laboratory also found that Dimorphos’ orbital velocity decreased after the impact.
Cheng and his colleagues said the transfer of momentum from the DART spacecraft to Dimorphos was magnified by the recoil of ejecta streams produced by the impact.
While the asteroid posed no threat to Earth, the hope is that the mission’s concept could work as a strategy to defend our planet from future threats from space.
A space rock the size of Dimorphos could cause continent-wide destruction on Earth, while the impact of one the size of the larger Didymos would be felt worldwide.
NASA has previously emphasized that the asteroids pose no threat to our home planet, but they were chosen because they can be observed from Earth-based telescopes right here on Earth.
The European Space Agency (ESA) is launching a mission in 2024 that will send a probe to Dimorphos and Didymos to study the pair in more detail.
Dimorphos orbits a much larger 780-meter-wide object called Didymos (pictured) 6.8 million miles from Earth
THE EARTH HAS HAD FIVE MAJOR EXTINCTION EVENTS WITH THE MOST FAMOUS A DINOSAUR KILLING ASTEROID
Five times, the vast majority of life in the world has been extinguished in what are called mass extinctions.
Late Ordovician mass extinction
The first of the traditional big five extinction events, about 540 million years ago, was probably the second most serious. Virtually all life was in the sea at the time and about 85% of these species disappeared.
Mass extinction in the late Devonian
About 375-359 million years ago, major environmental changes caused a long-lasting extinction event that wiped out large fish groups and halted the formation of new coral reefs for 100 million years.
Five times, the vast majority of life in the world has been extinguished in what are called mass extinctions. The best known is perhaps the End Cretaceous, which wiped out the dinosaurs. Artist’s impression
End-Permian mass extinction (the Great Die)
The largest extinction event and the one that most profoundly affected Earth’s ecology occurred 252 million years ago. As many as 97% of the species that leave a fossil record are gone forever.
End-Triassic mass extinction
Dinosaurs first appeared in the early Triassic, but large amphibians and mammal-like reptiles were the dominant land animals. The rapid mass extinction that occurred 201 million years ago changed that.
Mass extinction in the end of the Cretaceous
An asteroid slammed into Earth 66 million years ago and is often blamed for ending the reign of the dinosaurs.