Asteroids, more than just potentially dangerous rocks, are in their own right geologically diverse little worlds that tell the story of the origin of the solar system, but are still unknown. The Hera probe, which will be launched after the DART mission, aims to explore these “uncharted lands,” according to AFP.
DART mission image NASA/Johns Hopkins Applied Physics Laboratory
From Monday night to Tuesday, NASA’s DART mission will attempt to deflect an asteroid from its path by colliding with Dimorphos, a small “moon” that orbits a larger asteroid, Didymos, located 11 million kilometers from Earth. This experiment aims to reduce the orbit of the smaller asteroid around the larger asteroid, so that NASA engineers can see if humanity is able to voluntarily change the course of the asteroid that threatens our planet.
“Such a system of two asteroids is an ideal test bed for a planetary defense exercise, but it is also an entirely new environment,” Summarized by Ian Carnell, HERA mission coordinator at the European Space Agency (ESA), according to Agerpres.
HERA is named after the Greek goddess of marriage, and the European probe will be launched in October 2024, with an expected arrival in 2026 at the asteroid Demorphos. His goal: to return to “Crime scene” To assess the consequences of the effect induced by DART.
Thus, the test related to the deflection of a small asteroid will be fully documented, thanks to the information that will be collected by the devices on board the HERA probe (video cameras, lasers, high-resolution images, radar). The information obtained will help planetary defense experts to complete the computer models used with a high degree of reliability to extrapolate scenarios related to the impact on the asteroid.
“We need to know the nature and composition of asteroids, because they do not represent the same danger depending on the texture of the rock,” Bhavya Lal, NASA’s co-director, confirmed this week’s International Aeronautics Conference in Paris.
Scientists expect to be surprised by the results of these investigations.
“Because we know nothing of these orbs,” said Patrick Michel, HERA Mission Principal Investigator. “It’s a new world we’ll discover”he added.
This astrophysicist believes that asteroids “They are not simple boring rocks from space, but wonderful and intricate little geological worlds, with craters, basins, rock fields, and particle spitting.”
But researchers know very little about these regions due to the fact that the gravity on their surface is very low compared to that on Earth: the behavior of matter there. “Quite paradoxically, we can’t just rely on images to see how these asteroids behave, we have to touch them”Patrick Michel explained.
One example: a small explosion on the surface of the asteroid Ryugu (discovered in 1999) created a 15-meter-high crater, much larger than computer simulations predicted.
Also, although astrophysicists believed that the asteroid’s rock was solid, “Its surface behaves surprisingly like a liquid during impact.”
Back in time
Binary systems such as Didymos and the Dimorphos satellite make up about 15% of known and unexplored asteroids so far. With a diameter of 160 meters (the size of the Great Pyramid of Giza), Dimorphos will be the smallest asteroid ever discovered by humans At the end of the mission, a small satellite will attempt to land on the asteroid’s surface, to measure its bounce.
Such unprecedented documents will help astrophysicists go back in time, because asteroids are excellent “Holders of the History of the Solar System”, Patrick Michel said. These tiny telluric bodies have preserved the memory of the original formation of the solar system and its planets, which formed as a result of the collisions.
“Today, we are in an age when all solid surfaces in the Solar System contain craters. But to find the original scenario, we need to understand what happens when two objects collide. Not in a lab, but on a real scale, thanks to the DART-HERA mission duo,” Scientists explained.
The DART mission was launched in November 2021 from a base in California. After a ten-month journey, the American probe will hit the asteroid Demorphos on Monday evening at 23:14 GMT at a speed of more than 20,000 kilometers per hour.
The spacecraft is no larger than a car, and its target diameter is about 160 meters (half the height of the Eiffel Tower).
There is no reason to panic, because Demorphos is in no way a threat to the Earth: its orbit around the Sun passes at a distance of 7 million km from our planet.
The moment of impact has been announced as an amazing moment and can be viewed live on the US Space Agency’s website.
The goal is not to destroy the asteroid, but to twist it slightly through it Kinetic effect technology“.
Dimorphos is a satellite of the asteroid Didymos (780 meters in diameter), which orbits completely in 11 hours 55 minutes. The goal of the DART mission is to reduce Demorphos’ orbit around Didymus by about 10 minutes.
This change can be measured from Earth by observing the variation in brightness when the small asteroid passes in front of the larger asteroid.
To reach such a small target, the spacecraft will be headed for an autonomous flight for four hours, much like a self-guided rocket.
His video camera, Draco, will capture the first images of the asteroid at the last minute, at a rate of one image per second, visible directly on Earth with a delay of just 45 seconds. Three minutes later, a shoebox-sized satellite, called LICIACube that was launched a few hours before the DART probe, will pass within 55 kilometers of the asteroid to photograph the effects of the impact. The images will be sent back to Earth in the coming weeks and months.
The Hubble and James Webb telescopes will also monitor the event.
Very few known asteroids are considered dangerous to Earth, and none of them will come close to our planet in the next 100 years.
“But I guarantee you that if you wait too long, such a cosmic body will appear.”said Thomas Zurbuchen, science director at NASA.
Nearly 30,000 asteroids of all sizes have been cataloged near Earth (called Geocruisers, as their orbit intersects Earth’s). About 3,000 new asteroids are discovered each year.
Scientists say that all those whose diameters are more than one kilometer have already been detected. But they also say that at the moment, only 40% of asteroids more than 140 meters in diameter are known — and capable of destroying entire regions on Earth.
If the DART probe misses its target, it will have enough fuel to make another attempt in two years.