Status: 11/23/2021 8:07 p.m.
The space agencies of the USA and Europe are starting a spectacular experiment in defense against asteroids: The DART space probe is to be launched into space today and hit a double asteroid.
What would humanity do if a giant asteroid crashed toward Earth? So far only Hollywood has found an answer to this. US actor Bruce Willis set out on a sure-fire path into space to blow up an asteroid in the disaster film “Armageddon” a good 20 years ago. Now, for the first time in the history of space travel, science is trying to change the trajectory of an asteroid.
For this purpose, the refrigerator-sized probe DART (Double Asteroid Redirection Test) starts on its mission from Vandenberg Space Force Base in California. The target of the probe is the double asteroid Didymos – Greek for “twin”. It consists of a larger asteroid, which is the namesake, and a smaller asteroid. It’s called Dimorphos, has a diameter of 160 meters and circles around the larger moon at a distance of 1.1 kilometers. The DART probe is supposed to hit the smaller asteroid.
An illustration shows the DART probe and the double asteroid Didymos.
Image: AFP
Push out of orbit?
“Next year we will reach the asteroid at the end of September or in the first week of October and fly directly into it to find out how much we can move it,” explains Thomas Zurbuchen, NASA’s director of science. “Then ESA will launch a probe and look at the crater for additional information about the experiment.”
Will it be possible to change the orbit of asteroids with such an impact? Can you just push them away? And could one divert asteroids that are heading for Earth in this way in the future? The scientists want to find out.
Nobody on earth has to worry about the double asteroid: it serves as a “test object” and will fly past the earth at a distance of ten million kilometers in the coming year.
ESA probe HERA will follow in 2024
After the impact of the NASA probe, the ESA probe HERA – named after the Greek goddess – is to fly to the double asteroid in a follow-up mission in October 2024.
Michael Küppers, ESA project scientist for HERA, explains: “With the NASA experiment and observations of the double asteroid from Earth, one would see how the period of the small asteroid changes around the large one To determine the efficiency of the momentum transfer from the probe to the asteroid, one has to know the mass of the moon. “
To do this, the ESA probe will examine the asteroid in detail with scientific instruments and cameras. Two so-called CubeSats – satellites the size of a shoe box – are also supposed to land on the asteroid. “HERA then measures the mass of the asteroid to see how efficient the orbit change really is. HERA will also look closely at the impact crater. We also want to study the properties of Dimorphos in order to be able to scale the results of the impact,” explains Küppers.
So the scientists want to find out how transferable the results would be if an asteroid really hurtles towards Earth.
This is what the impact of the DART probe on Dimorphos should look like.
Image: dpa
Distract or blow up asteroids
At the moment around 27,000 so-called NEOs (Near-Earth-Objects) are known, i.e. near-earth asteroids and comets. Didymos is one of them. However, according to ESA scientist Küppers, less than ten percent are at risk of hitting the earth. In addition, many of them do not pose a major threat, as they are only a few meters tall.
“If it were a small asteroid, say the size of a football stadium, flying at a moderate speed, distraction would be the simplest idea,” says NASA Science Director Zurbuchen. “There are many ideas to ward off a large asteroid. One would be to split the asteroid, for example by exploding it with a bomb. But nobody has ever tried that in practice.”
Be prepared for risks early
Climate scientist Georg Feulner from the Potsdam Institute for Climate Impact Research explains what serious consequences it can have if a large boulder hits the earth: “66 million years ago, a huge asteroid impact triggered a major mass extinction, to which the dinosaurs in particular played a role Victims fell. “
The better you know risks, the better you can protect yourself against them – this was not least taught by the climate crisis and the corona pandemic.
Should the asteroid defense mission of NASA and ESA be successful, one would have an instrument at hand to defend the planet earth against asteroids in an emergency.