Asteroid Discoveries, 1980 - 2010

Check out this fantastic new video, which shows all of the asteroids in a time lapse as they were discovered over the last 30 years. In the bottom left corner, you can see the year and the number of asteroids steadily climbing:



Notice the huge increase in discoveries towards the end of the 1990s. That's thanks to automated systems like the LINEAR project, which has discovered over 226,000 objects since its inception. Like most illustrations of the solar system, though, this animation is not drawn to scale; the Main Belt look crowded here, but the actual distances between the asteroids are still very large.


I like to think about asteroids. There are so many of them, far more than can probably ever be named. They can seem commonplace and, compared to the pantheon of the planets, they may be mere afterthoughts. They tumble slowly through the blackness of space, utterly unaware of themselves, drifting endlessly on their lone path around the Sun, gently tugged by something or other over the eons. Nothing drives them but the elegant machinery of the universe.

Occasionally two of these austere mountains will meet each other on the lonely road, smash into each other, and cast their smithereens in all directions. Some of those bits may find their way to the Earth, burn up as they rocket to the ground or, astonishingly, survive the trip and end up in a field in Maine, or a car roof in Rome. They will be studied or sold, and put on display. And we know that these rocks are hearty travelers, so we can handle them.

Whenever I get the chance to hold a meteorite I think about how it got here. This small, heavy iron rock is just a tiny fragment of an enormous primordial monolith, and there’s no telling how long ago it was utterly destroyed – or at least transformed radically. Its precise history is unknowable, but its lineage is as ancient as our own.

The asteroids have orbited lazily since the birth of our solar system, intermittently disturbed, and sometimes pieces of them, quite by accident, end up here. But until their fiery arrivals here on Earth, these rocks had known only cold nothingness for billions of years. A rock from the sky reminds me how empty and lonely it is in the vast depths of interplanetary space, to say nothing of the inconceivable distances to our neighboring suns. In realizing how helplessly isolated we are from the friends that may await us among the stars, we can begin to understand at last the preciousness of our fragile world, and the imperative of its protection.