There is a lot of junk circling the Earth, and flying around in it is akin to dodge ball in space, some experts say. Satellites, discarded rockets and other bits of technology are speeding around the atmosphere, all moving together to create treacherous conditions. reports that scientists have joined together to call for a cleaning up of space before a serious collision occurs.

Experts estimate that space junk zips around the globe at speeds of up to 25,000 miles per hour with altitudes ranging from hundreds to thousands of miles. It can be made up of broken rocket motors, coolant released by satellites, debris of micro meteor hits, and even bits of paint from rockets. Some experts estimate there are more than 1 million objects speeding around our planet and all but 9,000 of them are smaller than a tennis ball. But it's the larger pieces that have scientists worried. reports on a particularly scary near-collision in space last month. A Chinese rocket and the European Space Agency's (ESA) huge Envisat Earth remote-sensing spacecraft almost had a head-on collision. The two objects were due to speed by each other with only 160 feet between them. The Envisat weighs 8 tons, while the discarded rocket weighs 3.8 tons. If they had hit, experts note that the ensuing debris would have created utter chaos in the atmosphere. Luckily, the Envisat was tweaked a few degrees out of the way to avoid a crash.

Scientists are extremely worried about the safety of the International Space Station, which is currently home to five astronauts from the United States, Japan and Russia. Heiner Klinkrad is the head of the European Space Agency's Space Debris Office in Darmstadt, Germany. As Klinkrad told, "A penetrating object hitting the ISS, and possibly causing a casualty onboard ... I think that would be the most dramatic case we could have." Klinkrad further worries that such an incident might turn public opinion against human spaceflight.

Last year, Russian and United States communication satellites smashed into each other, producing two large clouds of shrapnel. This worried NASA enough that they bumped up the launch of the space shuttle Discovery, giving it a chance of about 1 in 318 of being fatally hit by debris. Since then, scientists have been offering a spirit of international collaboration in fighting the perils of space junk. 

Avoiding space dodge ball is a mission that future space travelers will have to keep in mind. In 1978, NASA researcher Donald Kessler created the so-called Kessler Syndrome, which is the concept that space debris creates more debris. As he told, "The future debris environment will be dominated by fragments resulting from random collisions between objects in orbit, and that environment will continue to increase, even if we do not launch any new objects into orbit."

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