How do spacecraft get through the asteroid belt safely?
Being the pilot of a spaceship in a sci-fi movie is very difficult, especially when you are trying to elude pursuit by driving your ship at breakneck speed through the asteroid belt, because there are countless rocks side by side.
Passing through that commotion requires exceptional concentration and infinite skill, but also insane courage.
Just imagine that a mountain is falling on you and you have nowhere to turn because huge stones are rushing all around you and they are all aiming right at you.
It’s especially difficult when your ship’s turbo jet fails to avoid collisions with asteroids.
However, this is the case in science fiction literature and especially in films where visually it is much more dramatic than in books.
In reality, the passage through the asteroid belt, and we mean the densest one between Mars and Jupiter, is safe as far as collisions are concerned that rocket experts don’t even think about it.
At first glance it seems strange because there are so many asteroids. Only those whose diameter exceeds one kilometer are over one million – and that’s according to more modest estimates.
In a slightly more relaxed way, the number of kilometer-long asteroids rises to two million.
Of course, the number of asteroids increases drastically with their smaller diameter, so the number of such is not known, but it is estimated at billions.
And believe us, if a rock of only half a meter hits your ship, or even smaller than that, due to the high speed with which that rock moves in relation to you, that would be the end of your mission and life.
Still, engineers don’t think much about that problem, not only because they have much bigger other concerns about flight, but also because the path the asteroids fly and the way they spread out is big – between 1 and 1, 5 billion kilometers.
It’s hard to describe how much it is but take it this way. Put one grain of sand on the road, measure one kilometer from it, then put another grain on the ground, and you have proportionally reduced the size of the asteroid and the distance between them.
In nature, the average distance between two asteroids of the main asteroid belt is only slightly less than one kilometer.
Of course, in some places, asteroids are grouped into families, so their mutual distance is somewhat greater, but it is still a gaping space between two interplanetary rocks.
And in that proportion, your ship is much smaller than an imaginary grain of sand.
So, it turns out that it is much more difficult to hit an asteroid with your rocket than to avoid it.
Of course, this doesn’t mean that mission planners completely ignore asteroids and their trajectories, but they just don’t bother much because the probability of a collision is minimal: one in a billion!
