2016 saw the launch of the Osiris-Rex spacecraft with a bold mission: to meet an asteroid, collect samples and bring them back to Earth. A 7-year expedition involving Canadian researchers.

The asteroid in question is called Bennu. At a height of 500 meters - about the size of the Empire State Building in New York - it revolves around the Sun and passes near our planet. Bennu is one of the asteroids known as NEOs, that is to say, who evolve near the Earth. Like others, it is part of the asteroid belt, located between Mars and Jupiter.

Bennu, named after an Egyptian deity, has the advantage of being located at a reasonable distance from the Earth, which allows to go there in a relatively short time. In this case, Osiris-Rex will take a little less than two years to get to the asteroid.

This mission could even pave the way for the possibility of deflecting an asteroid threatening the Earth. Bennu himself would represent a certain threat to the Earth, but imprecise and expected in a few hundred years.

The collection of samples on Bennu will be done in a very special way: the probe will approach the asteroid and take its samples for just five seconds.

But what will they look for up there that we do not find here below? First, precious metals like platinum. Metals whose needs, especially for electronic equipment, are more and more important and are very rare on Earth. For example, it is estimated that a 500-meter asteroid could contain more platinum than has ever been extracted from the earth's subsoil. What excite some lusts.

The second precious element in space is water. It may seem paradoxical, but water in space is a way to get oxygen and hydrogen ... fuel for rockets. Today, sending fuel into orbit is prohibitively expensive. If it could be manufactured directly on site, it would provide the opportunity to refuel without the expensive need to escape the gravitational pull.