Space junk to come crashing down
Global warming may cause satellites to fall back to Earth.
Don’t look now, but there are tons of junk floating over your head.
In the past half-century we’ve launched thousands of artificial satellites into space, and they remain up there, circling our planet, whether they’re operational or not. NASA’s Orbital Debris Program estimates there are more than 6,000 tons of space junk in lower Earth orbit.
Ignoring for a moment that we’ve actually managed to pollute space (space!), the orbiting junkyard would seem to be a threat only to other satellites and spacecraft — that is, as long as it stays up there in orbit.
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But scientists are now concerned that global warming may cause more collisions between “dead” satellites and space debris, in turn increasing the risk of space junk crashing down to earth.
If you want to know what kind of impact a crashing space object can have on Earth, visit a town-sized impact site like Meteor Crater in Arizona. Or ask a dinosaur. Many of them are still bitter.
The problem is carbon dioxide emissions are cooling the upper atmosphere where most satellites and debris orbit. Though the greenhouse effect warms the lower atmosphere, where gases are trapped and heated by the sun, carbon dioxide has the opposite effect at greater altitudes. A cooled upper atmosphere exerts less “drag” on satellites, so that rather than orbiting through a thick soup they stream through a thinner thermosphere. The cooled upper atmosphere allows the debris to draw collectively closer to Earth and increases the chances of pieces crashing into one another.
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Even a tiny paint chip in orbit becomes a missile capable of smashing a satellite into thousands of pieces. With more debris comes a greater chance of collisions (a scenario known as the Kessler syndrome, named for Don Kessler, the "father of space junk") and more space scraps potentially in uncontrolled descent toward Earth.
A similar phenomenon is what caused Skylab to crash down. Space.com notes that nobody was hurt when pieces of Skylab rained down southeast of Perth, Australia, though the nearby town of Esperance did charge NASA $400 for littering. We also dodged disaster when the Russian space station Mir, which was as large as six school buses, fell into the South Pacific near Fiji.
But with more satellites in orbit, more collisions, and a thinning upper atmosphere, we won’t always be so lucky. More frightening was when the nuclear-powered Cosmos 954, a Soviet spy satellite, came down and spread radioactive debris over northwestern Canada.
We earthlings have become reliant on artificial satellites for communication and scientific experimentation, and we've left the dead ones up there based on the principle that what goes into orbit, stays in orbit. Until it doesn’t.
Photo: Pete Turner/Getty Images
The good news is that approximately 100 tons (per NASA) of natural and man-made space debris falls every DAY! Mother Nature is tidy-who knew. If we could find a way to put less clutter up there, the skies would get clearer naturally. I'm pulling for super-conductor powered anti-gravity ships. Humor me, they said faster-than-sound was impossible, too. Have a Nice Day.....Chicken Little
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