“Tonight the earthlings will be able to sleep better”. Elena Adams, the systems engineer for DART, NASA’s mission to crash a ship into an asteroid, said it only half jokingly. It was shortly after the object developed by the Johns Hopkins University Applied Physics Laboratory impacted a small celestial body millions of kilometers from our planet.
“Our first planetary defense mission It has been a success» celebrated. The objective was to study how the trajectory of an asteroid heading towards Earth with catastrophic power can be changed. It is an issue that has fascinated science fiction and has reached the collective imagination with films like ‘Armageddon’ or the most recent ‘Don’t look up’. But which, in turn, is as real as the universe itself. 65 million years ago, a meteorite with a diameter of ten kilometers crashed into what is now the Yucatan Peninsula, causing widespread destruction across the planet. Extinct much of the flora and fauna, including dinosaurs.
The possibility of impacts with this destructive capacity is low. They occur once every ten years and no risk in sight.
But the impact of other smaller asteroids is very dangerous. One that exploded in 1908 on the Tunguska River in Siberia was only fifty meters in diameter, but it blew up 80 million trees in an area of 2,100 square kilometers. Another smaller one, with a diameter of twenty meters, also in Russia, in Chelyabinsk, emitted in 2013 an energy equivalent to thirty nuclear bombs like the one that fell in Hiroshima.
Governments and space agencies take that threat more and more seriously and projects for monitoring meteorites with the potential to impact the earth have multiplied.
The DART spacecraft was launched from the Vandenberg Space Base in California in November of last year. Have the size of a refrigerator large (‘dart’ means ‘dart’, in English) and has traveled through space a distance of more than eleven million kilometers from Earth until this Friday it found its objective.
It is Dimorphos, a small asteroid that orbits around a larger one, Didymos. At 1:14 a.m. Spanish time, as planned by the NASA team, the spacecraft impacted Dimorphos.
The camera embedded in the spacecraft sent images of its target live to Earth. Every few seconds, it looked closer and closer to the asteroid. In the last photographs, the rocky and rough surface of Dimorphos, which has a diameter of 150 meters, was observed in detail. At that time, the ship was traveling to 14,000 kilometers per hour.
“We have an impact,” confirmed the live broadcast of the US space agency at that time. “It’s a historic event,” Ed Reynolds, head of the Johns Hopkins project, said afterward. Scientists from this university detailed that the ship had impacted at a distance of 17 meters from the center of the asteroid. Almost as hit the target’s eye.
Now it remains to be seen the exact result of the mission: what effects the impact has on Dimorphos’s trajectory. The expectation of scientists is that the speed of the asteroid will increase in its orbit around Didymos. Until now, according to measurements from Earth, it took 11 hours and 55 minutes to complete one orbit. It is now expected to do so seven minutes faster and to be heading towards the larger asteroid.
“In the next months we will have an exact confirmation of what is the change that is achieved, ”said Adams. The images of the impact and its result will serve to obtain more information about the composition of the asteroid and the result of the mission. Scientists expected that the impact would have created a cloud of debris between ten and twenty meters high, depending on the composition of the meteorite.
Dozens of high-capacity telescopes around the world had their eyes on the mission, although the distance it’s too far enough to feel the impact. Just like the James Webb or Hubble Space Telescopes. The best witness has been LICIACube, a small ship, the size of a shoebox, created by the Italian Space Agency, which has followed in the footsteps of the DARTS mission in order to take pictures. These, shipped with a more rudimentary system, are expected to arrive in the next two days to the earth.
To see even more details, we will have to wait until four years from now. The European Space Agency plans the launch in October 2024 of a ship, Hera, which will reach Dimorphos at the end of 2026 to, among other experiments, evaluate the result of the impact.