Bennu, never before so close to the asteroid

OSIRIS-Rex, the small probe of the NASA which is travelling around the asteroid Bennu, doesn’t let anyone talk a lot about itself. However it’s working no stop, by giving us astonishing images filled with informations and by making things that the human was never able to do before.

But there is much, much more in the mission of OSIRIS-Rex, the asteroid around which it orbits is considered one of the potentially dangerous ones for the planet Earth. But it’s still not all. It’s believed already for a while that Bennu is a twin of that asteroid that million of years ago brought the life on our small planet.

How many secrets hidden in a such small cosmic stone, which has a diameter of just half kilometer.

The discovery of Bennu

Bennu was discovered recentelly, in the 1999, exactly. It’s been considered an asteroid Apollo, which means is part of a group of asteorids really close to Earth and so potentially dangerous for it. Furthermore Bennu is in the category of the carbonaceus asteroid of type B, which could so hide inside it the building blocks of life.

The mission of the NASA OSIRIS-Rex provided to reach one of the asteroids of this band and to examinate it closely, both to understand the characteristics of it and to avoid a catastrophe in case the probabilities of impact will increase.

At the end it’s been chosen as the target of the mission right the asteroid Bennu. The launch happened in the 2016 and OSIRIS-Rex reached its final orbit the 3rd December of the 2018. Since there it’s examinating the asteroid, by shooting incredible images that send back to Earth. Recentely it made a record, by shooting a picture at just 600 meters from the surface, with a precision of 50 centimeters.

But the mission has still so many challenges for OSIRIS. It will have, infact, to directly land on the asteroid, during the 2020, to collect samples from the ground and bring them back home, on Earth. The return is predicted for the 2023.

The discoveries during the first months of permanence in Bennu’s orbit

It’s been now seven months that OSIRIS-Rex is in orbit around the asteroid and what did we discover until now? Bennu is filled with water, which is trapped in the underground by a huge number of hydrate minerals. The surface is covered by craters, caves and holes, which is sign of its long and troubled travel through the Solar System.

Finally, it would seem that Bennu once was a part of a much bigger object, which crushed, probably after an impact, happened, likely, between the 700 million and 2 billion of years ago.

The discovery of the water on the asteroid seems to conferme the hypothesis that it arrived on the Earth brought by a Bennu’s twin.

“It’s the confirme about how much the water is important on the asteroids, which are considered the responsible of the injection of water on the Earth. The Earth took shape in a dry zone and only after the impact with asteroids like Bennu it obtained organic matter and water of extraterrestrial origin”, explains John Brucato, author of some of the researches about Bennu.

Finally, it would seem that Bennu, during its long travel through our solar system, englobed parts of other asteroids, which came from other places of the solar system and from different ages, becoming an incredible source of informations about the whole system.

A danger for the Earth

We mentioned about the fact that Bennu is a possible threat for the Earth. By the way the informations that we took by getting such close to it are much more important than every hypothetical apocalypse. Even because the asteroid won’t get close to Earth before than hundred years. We so have all the time to be prepared for its arrival.

Currently the probabilities estimated that in the next century Bennu will hit the Earth are about 1 on 2700 and the instruments that we have now aren’t enough to avoid the catastrophe. But we have more than a century to prepare ourselves and for sure we will find a way to stop the threat.

Meanwhile we should go on looking for what this small and precious asteroid is hidding, to find out some of the universe’s mysteries and maybe the origin of the life on the Earth.

This post is also available in: Italiano