When I was a kid I was hit with a Big Gulp that was jettisoned from a passing car... it tasted like Mountain Dew. Needless to say, ever since I have been uneasy about being the target of projectile litter, so imagine my discomfort when I read that a 1,400-pound tank of toxic ammonia coolant is plunging to earth.

Apparently the refrigerator sized piece of litter was jettison from the International Space Station on July 23rd, 2007 and has been making it's way back from wince it came. It's expected to land sometime today.

It is expected to break up upon reentry, but scientists expects 15 pieces of the tank to survive the re-entry, ranging in size from about 1.4 ounces to nearly 40 pounds.

Mike Suffredini, NASA's space station program manager speculated, "If anybody found a piece of anything on the ground Monday morning, I would hope they wouldn't get too close to it."

Apparently terrestrial space trash is not uncommon. According to the European Space Agency, as of 2003 there were approximately 10,000 cataloged pieces of space debris floating around our planet made up of...

• miscellaneous fragments — 41%
• old spacecraft — 22%
• rocket bodies — 17%
• mission-related objects — 13%
• operational spacecraft — 7%

A main propellant tank of a Delta 2 launch vehicle which landed in Georgetown, Texas, on Jan. 22, 1997.

Luckily, of those that trash that makes it's way back to earth, the majority burns up reentering the atmosphere. The rest that doesn't burn up crashes here on Earth, and so far no injuries have been reported.

Australian farmer, James Stirton, found this Composite Overwrapped Pressure Vessel on his Outback cattle farm.

The likely hood of this cosmic litter hitting anyone is pretty slim. The earth is 2/3 covered by water and only a small fraction of the land is actually covered by people, but for some reason the idea that 1,400-pound tank of toxic chemicals probably won't hit me is not that comforting. You probably won't get beaned by a discarded soda as you walk down the street either.

Sources: 1, 2, 3, 4, 5