Asteroid defense: Hera probe prepares to embark on 11 million kilometer journey

Her name is Hera, after the Greek goddess of marriage. The small probe, weighing just over a ton and barely the size of Twingo, is about to embark on an 11 million kilometer journey to the asteroid Dimorphos. Its goal: to collect data for better protect yourself from possible collisions with these celestial objects and not end up like the dinosaurs.

To better understand the European Space Agency’s (ESA) Hera mission, we have to go back two years: in September 2022, Dimorphos becomes the target of the Dart mission. This 600 kg probe developed by NASA falls on purposeat a speed of 24,000 km/h, on the surface of an asteroid the size of a football field, to divert its trajectory.

Mission Complete : While Dimorphos, orbiting the larger asteroid Didymos, takes nearly 12 hours to orbit its 800-meter-diameter larger sister, the impact shortens that orbit by more than half an hour. “This Dart probe deflection method is one of the most effective that can be used.”– confirms Juan-Luis Cano, planetary defense specialist at the European Space Agency.

The Hera probe, after two years of travel, will return to the crime scene to observe what is happening. consequences of the Dimorphos impact, such as the size and morphology of the crater.. “The dart was destroyed during the impact, so we need to return to the site to understand what form Dimorphos is in today.”explains Ian Carnelli, program manager at ESA, the European Space Agency.

Hera will be equipped with 12 toolsincluding two types of “Cube-Sat” “The drones, travel companions, which we will deploy near the asteroid, explains Ian Carnelli. They will fly very close and perhaps land on the surface, and therefore measure gravitational properties, thermal properties, to finally understand how these double asteroids form and how we can interact with them.. So the question is, who are we dealing with if, in the distant future, we need to deflect an asteroid to save Earth?

“The bricks from which the solar system was formed”

Because the other goal of the mission is “understand the history of our solar system“, explained in 2022 astrophysicist Eric Laguadec on France Bleu. “Our solar system was formed more than 4.5 billion years ago. Planets, including Earth, were formed by the accumulation of small asteroids. Therefore, if we want to understand how the Earth was formed, we must understand how these asteroids are formed (…) the structure of these building blocks from which the Solar System was formed.”.

“Asteroids are far from boring pebbles, but real geological worlds with avalanches, craters, and basins. But we’re still at the stage where we’re trying to understand what we’re observing and their behavior.“Adds Patrick Michel, scientific director of the Hera mission, researcher at the Côte d’Azur Observatory and asteroid specialist. These celestial objects really “behavior that defies our intuition because their environment is very different from that on Earth” – the expert emphasizes.

Are asteroids really a threat?

“At the moment we are observing asteroids and we understand that there are no potentially dangerous ones in the next century,” – says Eric Laguadec. “The problem is that there are hundreds of thousands of asteroids that we don’t know about.” continues Juan-Luis Cano, planetary defense specialist at ESA. “Some can be a threat, it all depends on their size. A 50-meter object crashing into the city would be a real disaster. And 50 meters is not a very large size.” for an asteroid. Without going that far, in 2013 in Russia almosta thousand people were injured consequences of a meteor shock wave with a diameter of 15 meters.

Hence the different missions. Hera, which is currently located in the Netherlands, near The Hague, in the hangars of the European Space Technology Center, where it is undergoing numerous tests, will deliver his flight is in October from the USA. Arrival at Dimorphos is planned for 2026. And in 2029, the passage of the asteroid Apophis at a distance of about 32,000 km from Earth will provide a new opportunity, “natural laboratory” to study these stars, according to Patrick Michel. A mission is also being prepared to study the behavior of Apophis during its passage, without the need to touch it, since it will be visible from the ground.