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Mankind is an equal-opportunities polluter, dirtying not just our planet but also space.

And it's getting worse. The video above, a visualisation of the increase in space debris, was created by Stuart Grey, a lecturer at University College London, and released by the Royal Institution of Great Britain. Starting with 1957 when the first spacecraft Sputnik I went into space, it covers the steady rise in space junk up till 2015.

What's in there? Pieces of old satellites, used rocket stages, and fragments from collision, erosion and disintegration of spacecrafts. NASA has been keeping track of about 20,000 pieces of debris that are bigger than an apple, and a total of about half a million pieces of space junk that are larger than a marble.

These objects travel at speeds of up to 17,500 miles per hour and, though small, can cause significant damage to any object they collide with.

A report in the International Business Times says, "Beginning with Sputnik I in 1957, closely followed by Explorer I a few months later, there were already more than 200 objects in orbit over Earth when Yuri Gagarin made the first manned flight into space in 1961. Less than 20 years later, in 1980, nearly 5,000 objects in orbit could already be tracked. As space programmes extended their reach, debris began to be left farther away from Earth.

"Another 20 years later, in 2000, the number of tracked debris stabilised at about 9,000 objects. However, a Chinese missile test in 2007 alone added 2,000 pieces of debris, and a collision between a defunct Russian satellite and a functioning commercial satellite in 2009 added another 2,000 pieces of junk to the planet's orbit. The largest piece of debris is about the size of a bus, according to Grey’s visualisation."

Scientists track space junk to ensure that it doesn’t collide with functioning satellites, and the International Space Station has to periodically move out of the way of space debris to avoid being hit. In 2006, the space shuttle Atlantis collided with a fragment of microchip – the tiny piece of debris blew a hole in the shuttle’s cargo bay radiator panels, and in 2013 a small stone went through the ISS's solar array.

NASA's website states, "NASA and other space agencies are doing many things to reduce the problem of orbital debris. The upper stages of launch vehicles, and some satellites, are being placed in lower orbits. This location will cause them to re-enter the atmosphere and burn up sooner.

"Since 1988, the United States has had an official policy to keep the creation of new orbital debris to a minimum. NASA even has an Orbital Debris Program Office at Johnson Space Center in Houston, Texas. This office looks for ways to create less orbital debris. It also looks for ways to get rid of debris that is already in space. Many US aerospace companies also follow guidelines to reduce the creation of debris. The Russian, Japanese, French and European space agencies are keeping the creation of new debris low, too."

Possibly the only value that the orbiting junk has yielded so far is the storyline of the film Gravity. Astronauts making repairs to the Hubble Space Telescope stray into the path of fast moving debris and most die as a result, leaving one woman to fend for herself.