When Sputnik 1 became the first artificial satellite to circle the globe on October 4, 1957, people all over the world tuned in to hear its distinctive bleep. From certain locations, it was also possible to see the satellite as a point of light tracking across the sky.
There are now thousands of man-made objects circling the globe. These include the International Space Station, the Hubble Space Telescope, working satellites, dead satellites, discarded rocket stages, fragments from break-ups and other space junk. As has already been mentioned, installations around the world track about 10,000 of these objects, all of which are larger than a melon. There are probably thousands of smaller pieces that are not tracked.
Hundreds of these orbiting objects are visible to the naked eye and thousands more are visible with the aid of binoculars or a telescope. With so much orbiting the Earth, it can be quite difficult to imagine the interest that the first man-made satellite caused. Sputnik 1 was the dawn of a new age. Radio stations broadcast the signal emitted by the satellite, while other radio stations closed down to enable listeners to tune their shortwave radio receivers to the bleep.
KeywordsInternational Space Station Satellite Laser Range Deep Space Space Debris Geosynchronous Orbit
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