In just one day, the Earth experienced the missed collision with the asteroid 367943 Duende and the explosion in the atmosphere of another asteroid, injuring more than 1000 people.
It was February 15th in 2013, was the day many realized that Earth is a vulnerable bubble.
Asteroids are a direct connection between our planet and interplanetary space. Craters like the Barring in Arizona remind us of this: the dinosaurs went extinct due to the impact with an asteroid not far from there.
Yet somewhere in the universe asteroids can also carry life from one planet to another. The world awaits new landings on the moon and then on Mars, but I say: let's remember the asteroids, here are at least 4 good reasons to do so.
They can also kill us.
The Chelyabinsk incident was filmed by a camera car, no one had noticed the meteor before. Fortunately, no direct victims of the explosion were recorded. We may not be so lucky next time. Ditto for the recent Puerto Rico accident, fortunately without consequences.
Going only to the asteroids already known, there is only a slim possibility that they could collide with the earth in the coming decades.
Among them, 6 are those with an “unpleasant” trajectory that can affect us in the next 150 years.
They can contain water
Astronomers debate the origins of water on Earth, how it could have arrived billions of years ago, carried by comets and asteroids.
NASA's Dawn spacecraft visited Ceres, the largest known asteroid, and found water on its surface. It is no coincidence that NASA itself classifies Ceres as an "ocean world".
They tell us how the solar system was formed
The surface of the asteroids is not affected by erosion like that of the Earth because the asteroids have no atmosphere.
This means that the craters on the asteroids are in a perfect state of conservation, presenting a perfect photograph of how much our solar system has gone through during the last 4 billion years.
In other words, asteroids function as real "time capsules" that tell us about the universe.
They tell us how the solar system will die
In 6 billion years ago, when the Sun has exploited all its hydrogen, it will begin to change becoming a white dwarf. It is a last stage for a star. During this transformation, the Sun enlarged until it swallowed up Mercury, Venus and perhaps us too.
At least 5 planets in the solar system, however, will survive this transformation. And with them several asteroids.
It is therefore clear that the analysis of asteroids from other points in the universe can tell us a lot about their interaction with other white dwarfs, and about the process of "extinguishing" that characterizes star systems. However, they can also tell us a lot about the ideal places to host us when we start a space colonization.