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Space is where our future is — trips to the Moon, Mars and beyond. Most people would think that apart from comets (彗星) and stars, there is little else out there. 1． Scientists are now concerned that if we don’t clean it up, we may all be in great danger.

The first piece of space junk was created in the year of 1964, when the American satellite Vanguard I stopped operating. 2． However, since it kept orbiting around the Earth without any results, scientists became increasingly comfortable abandoning things that no longer served any useful purpose in space.

3． The junk varies from tiny pieces of paint chipped off rockets to cameras, huge fuel tanks, and even odd items like the million-dollar tool kit that astronaut Heidemarie Stefanyshyn Piper lost during a spacewalk.

The major problem with the space trash is that it may hit working satellites and damage travelling spaceship. In addition to this, many pieces of junk may crash with each other and break into pieces which fall back to the Earth. 4． Ground stations have been built to monitor larger pieces of space trash to prevent them from crashing into working satellites or space shuttles. 5． They will stop littering in space and to clean up the trash already there.