Many people know that trash is a big problem on planet Earth. What many people don't know is that trash has become a problem in outer space too.
Statistically, there are more than 22,000 pieces of junk in space around the earth. And these are just the items that we can see from the surface of the earth by telescopes or radars.
Objects, like bits of old space rockets or satellites, move around the planet at very high speeds, so fast that even a very small piece can break important satellites or become dangerous to people, particularly astronauts. If the tiniest piece of junk crashed into a spacecraft, it could damage the vehicle. That's because the faster an object moves, the greater the impact if the object collides with something else.
To help minimize additional space junk, countries around the world have agreed to limit the time their space tools stay in orbit to 25 years. Each tool must be built to fall safely into the earth's atmosphere, or the mass of gases that surround the earth, after that.
Many scientists are also proposing different ways to clean up space junk. The Germans have been planning a space mission with robots that would collect pieces of space trash and bring them back to Earth so that they can be safely destroyed.
"In our opinion the problem is very challenging, and it's quite urgent as well," said Marco Castronuovo, an Italian Space Agency researcher who is working to solve the problem. Many of these objects are tools that help people use their cell phones or computers.
"The time to act is now; as we go farther in time we will need to remove more and more fragments," he says.
A. One reason that it's urgent is that countries are sending more and more objects into space.
B. There are also millions of smaller pieces of junk that we can't see.
C. Blowing up older satellites with a missile may create thousands of smaller pieces!
D. In the upper parts of the atmosphere, it will burn up.
E. When two objects in space collide, the two objects break into many smaller pieces.
F. Years of space exploration have left tons of "space junk" in orbit around the planet.
