Duck and cover, 21st Century-style

Thursday was a close call for the International Space Station when a piece of space debris the size of a marble hurtled past and within just three miles, as reported by CNN. Station crew were ordered into the Soyuz capsule just in case an emergency evacuation was necessary, the article stated.

The International Space Station was nearly taken out by a chunk of satellite debris the size of a marble. Photo: NASA.

The idea that something barely a centimeter across can be that big a danger is pretty eye-opening, given that the amount of junk circling our planet runs into the tens of millions of objects, according to NASA’s Orbital Debris Program. And while the program’s websie says the space station should be tough enough to handle an impact by debris up to a centimeter in size, the real danger comes from the 200,000 objects that range from one to ten centimeters in size, and the 17,000 that are even bigger than that.

Not all the debris shares the same orbital altitude as the space station, of course, but there’s plenty of stuff circling Earth at varying altitudes, which could put any number of commercial and government satellites at risk. The best recent example is the Feb. 10 collision of the Cosmos 2251 satellite (a defunct Russian communications rig) and the privately owned Iridium 33 satellite. That orbital wreck produced more than 500 pieces of debris, all of which is being tracked (the folks at spaceweather.com are on top of new developments in that arena). Some small pieces have started falling into the atmosphere — nothing big enough to survive re-entry, it is believed — but it could be years before it’s all cleared out of orbit and indeed may never be.

And by then, even more junk — from other collisions or just the flotsam that accompanies a standard launch — will join the orbital traffic jam. Bonus: Space Weather has a user-submitted video showing the leftover chunk of Iridium 33 passing through the star field at this link.