"Let's go burn down the observatory so this will never happen again."

People (like my friend "Dezmond") are rightfully excited about the photos that are starting to come back from Mars. Like anyone with a faint pulse and a rudimentary imagination (and I like to think I have a little more than that), I'm fascinated by deep space.

Exploring Mars is the fun part. In this month's Atlantic, Gregg Easterbrook writes about the scary part: The discovery of an increased likelihood that a comet or meteor could explode on or near our planet's surface, causing catastrophic damage. Or, as the Incredible Hulk might put it, the chances that rock smash Earth.

The whole piece is worth reading, if you're interested in this kind of thing; meaning, if you're interested in your survival. Easterbrook writes:

These standard assumptions—that remaining space rocks are few, and that encounters with planets were mainly confined to the past—are being upended. On March 18, 2004, for instance, a 30-meter asteroid designated 2004 FH—a hunk potentially large enough to obliterate a city—shot past Earth, not far above the orbit occupied by telecommunications satellites.

As is made clear, this was not a big asteroid, and obliterating a single city would be lucky compared to other potential outcomes. You can see a brief video of that asteroid (on a loop) by going here. (A meteor zooms by toward the end, trying to steal the show. Don't encourage it.)

As you might imagine, Easterbrook thinks the lack of funding and research for this sort of thing -- against a renewed fever for getting back to the moon -- is misguided. In any case, the piece is a good reminder of how unfathomably large the universe is:

As for extending our presence, a manned mission to Mars is at least decades away, and human travel to the outer planets is not seriously discussed by even the most zealous advocates of space exploration. Sending people “beyond” the solar system is inconceivable with any technology that can reasonably be foreseen; an interstellar spaceship traveling at the fastest speed ever achieved in space flight would take 60,000 years to reach the next-closest star system.