Thousands of pieces of "space junk" orbit our planet.
Click on image for full size
Image courtesy of ESA.
Whether on Earth or in Space, human activity creates waste. Like the Earth's environment, the space environment is getting more and more cluttered. There are currently millions of man-made orbital ruins that make up "space junk". Unfortunately, the past 45 years of space exploration have generated a lot of junk. Orbital debris includes things such as hatches blown off space modules, paint fragments from the space shuttle, or satellites that are no longer in use.
Most space junk is very small (for example, paint flecks). But there are thousands of objects orbiting Earth that are bigger than a baseball. These objects are tracked by ground-based radars.
Human-made debris orbits at a speed of roughly 28,000 km/hr (17,500 miles/hour)! Think of the damage even a small speck of paint could do if it hit a spacecraft at such a high speed! Even an object as small as small as a grape has enough kinetic energy to permanently hurt a medium-sized spacecraft!
Some spacecraft have shielding to protect from damage caused by space junk. It is also sometimes possible for a spacecraft to move out of the way to avoid getting hit by debris. The Center for Orbital and Reentry Debris Studies (CORDS) helps space mission controllers plan so as to avoid impacts between their spacecraft and space junk.
Shop Windows to the Universe Science Store!
Our online store
on science education, classroom activities in The Earth Scientist
specimens, and educational games
You might also be interested in:
You may think that most objects in space that orbit something else move in circles, but that isn't the case. Although some objects follow circular orbits, most orbits are shaped more like "stretched...more
In February 2009 two satellites in Earth orbit crashed into each other and were destroyed. This was the first time ever for a major collision between two satellites in Earth orbit. The satellites were...more
The Hubble Space Telescope (HST) was one of the most important exploration tools of the past two decades, and will continue to serve as a great resource well into the new millennium. The HST found numerous...more
Driven by a recent surge in space research, the Apollo program hoped to add to the accomplishments of the Lunar Orbiter and Surveyor missions of the late 1960's. Apollo 11 was the name of the first mission...more
Apollo 12 was launched on Nov. 14, 1969, surviving a lightning strike which temporarily shut down many systems, and arrived at the Moon three days later. Astronauts Charles Conrad and Alan Bean descended...more
Apollo 15 marked the start of a new series of missions from the Apollo space program, each capable of exploring more lunar terrain than ever before. Launched on July 26, 1971, Apollo 15 reached the Moon...more
NASA chose Deep Impact to be part of a special series called the Discovery Program on July 7, 1999. The Discovery program specializes in low-cost, scientific projects. In May 2001, Deep Impact was given...more