NASA has completed this Tuesday night one of its most striking missions in recent times: it has launched a spacecraft to deliberately crash it into an asteroid. It’s a rehearsal in case humanity needs one day to stop a giant space rock from killing life on Earth.
It may sound like Science fiction, but the DART (Double Asteroid Redirection Test) is a real experiment.
Broadcast live on NASA television, the aircraft took off at 10:21 p.m. local time on Tuesday (06:21 GMT) aboard a SpaceX rocket from Vandenberg Space Force Base in California.
His target is Dimorphos, a “moon” of about 160 meters (two statues of liberty) wide, surrounding a much larger asteroid called Didymos (780 meters in diameter). Together, they form a system that orbits the Sun.
“Asteroid Dimorphos, we’re coming for you!”NASA tweeted after the launch.
The impact should occur in autumn 2022, when the pair of rocks are 11 million kilometers from Earth, the closest point they can get to.
What we are trying to learn is how to deflect a threat“NASA chief scientist Thomas Zuburchen said in a press conference call about the $ 330 million project and the first of its kind.
To make it clear: asteroids pose no threat for our planet. But they belong to a class of bodies known as Near Earth Objects (NEOs). These are asteroids and comets that come within 50 million kilometers of our planet.
NASA’s Planetary Defense Coordination Office is most interested in bodies that have a size greater than 140 metersSince these have the potential to devastate cities or entire regions with an energy several times higher than that of normal nuclear bombs.
They know each other 10,000 near-Earth asteroids 140 meters or more in size, but none have a significant chance of impact in the next 100 years. But – an important caveat – it is estimated that only 40% of these asteroids have been found to date.
Impact at 24,000 km / h
Planetary scientists can create miniature impacts in laboratories and use the results to create sophisticated models of how to deflect an asteroid. But these models are based on flawed assumptions, so they want to run a real-world test.
The DART probe, which is a box with the volume of a large fridge and limousine-sized solar panels on each side, will crash into Dimorphos at something more than 24,000 kilometers per hour, which will cause a small change in the movement of the asteroid.
Scientists say that these rocks are a “Ideal natural laboratory” for the test, because Earth-based telescopes can easily measure the variation in brightness of the Didymos-Dimorphos system and calculate the time it takes for Dimorphos to go one full circle around its big brother.
Its orbit never intersects our planet, providing a safe way to measure the effect of the impact, which is scheduled to occur between September 26 and October 1, 2022.
Andy Rivkin, head of the DART research team, said the current orbital period is 11 hours and 55 minutes. The team expects the hit to reduce Dimorphos’ orbit by about 10 minutes.
There is some uncertainty about the amount of energy to be transferred with the impact, since the internal composition and porosity of the small moon is unknown. The more debris generated, the more push Dimorphos will receive.