Look! Up in the sky! It's a bird. It's a plane. It's ... a paper glider?

Cygnus, the swan, has flown solo in the Milky Way for eons, but soon he'll be joined by a gaggle of companions. The Japanese team on the International Space Station will release a constellation of high-flying paper airplanes to research reentry without traditional spacecraft.

These celestial origami will soar at 17,000 miles per hour when they hit the atmosphere. This is scorching along faster than a speeding bullet - by a factor of 20 times a .22 caliber rifle round. At such a speed air would turn a man of steel into glowing vapor, creating a streaking flash across the sky; however, these super-gliders are treated to withstand extreme heat, while quickly bleeding off speed before piercing through denser atmosphere that would cook their goose in an instant. Once fully immersed in air, they'll migrate leisurely down to earth, silently searching for an unsuspecting teacher's chalkboard to strike.

Chicken Little wasn't kidding when she called, "The sky is falling!" Earlier this year, a satellite spiraling back to earth was about to become a shooting star. Shooting satellites seemed like a good strategy to prevent a land strike, and the Navy scored a direct hit that disintegrated US 193 into pieces that were vaporized as a harmless meteor shower.

Annihilation of Skylab wasn't possible when it fell in 1979, and huge chunks of searing metal more powerful than a locomotive smashed into the outback of Australia. One Australian municipality even fined the United States $400 for littering.

Russia's MIR space station was equally spectacular when it augured in near Fiji seven years ago. (HAL's quote in "2001: A Space Odyssey" seemed ironically prophetic: "This sort of thing has cropped up before and it has always been due to human error.")

These events drew stellar media coverage, unlike thousands of other scraps that fall from space every year.

There are 4 million pounds of clutter circling the globe, and far more will be left up there in the future. This debris includes spent boosters, missing gloves, slippery tools, defunct satellites, port-a-potty packages and other miscellaneous flotsam. Some 18,000 items are tracked, with roughly a third of those particles being residual riffraff from the Chinese demolition of a satellite last year. The shrapnel from that test will threaten space systems within 2000 miles of earth for about 40 years.

US 193's destruction also briefly increased the number of fragments, though nearly all of it fell from the heavens in forty days and forty nights. At orbital velocities, tiny objects pack a massive wallop. A marble-sized aluminum ball striking a satellite at 33,000 feet per second would have the same impact as a 60-pound safe traveling 60 mph.

The craters on the moon are visible testament to how powerful cosmic billiards are in our galaxy. Fortunately, Jupiter is a vacuum cleaner with intense gravity that absorbs most extraterrestrial clutter before it reaches the terrestrial planets. Jupiter showcased this superhuman strength in 1994 by crushing Comet Shoemaker-Levy 9 and swallowing the crumbs like a handful of chocolate chips.

Meteor Crater in Arizona is a 50 millennia-old monument proving that Earth still gets clobbered now and then. (I also got clobbered in Meteor Crater for teasing my sister, but that's another story). This crater is a meager divot when compared to a cataclysmic event 65 million years ago that obliterated the dinosaurs and opened the door for mammals to inherit the earth.

Meteor visits are not just ancient history. A mere century ago, the Tunguska meteor blew up about five miles above Siberia, blasting away 80 million trees in an 800-square-mile region with the force of a 10-megaton warhead. As destructive as this event was, Mother Earth was prepared with her shields up: the airbag surrounding our planet blunted this meteor's force, preventing world-wide devastation.

We won't always be so fortunate. Somewhere in the Oort Cloud is a huge chunk of rocky ice slowly tumbling toward our sun. Gravity from the Jovian planets will twist this meteoroid, fracturing it into many smaller pieces. The gas giants will capture some rubble, but some fragments will continue the descent toward the center of our solar system.

Most fragments will harmlessly glide by Earth and continue on their journey, but history shows it is only a matter of time until one finds Earth so attractive that it will just have to drop in. This alien visitor won't listen to our shouts of terror. In space, no one can hear you scream.

Fortunately, a major event like this is unlikely to happen within our lifetime, so there's no need to borrow Chicken Little's umbrella.

If, however, you happen to see a paper airplane fluttering to the ground and can't read the Haiku instructions, please take it to your nearest mild-mannered reporter at the Daily Planet.

Paul Heumphreus is an electronics engineer who resides near St. Peters. He is one of 18 Opinion Shaper columnists for the Suburban Journals of St. Charles County. Opinion Shapers are chosen annually to write five columns on topics of interest to them.