898 The number of active satellites currently in orbit around Earth, according to the Union of Concerned Scientists’ Satellite Database. The countries that have the most satellites in orbit: the United States, with 463; Russia, with 90; and China, with 48.
30 The number of days it will take a satellite to fall to Earth from a low altitude of 190 miles. Satellites at 250 miles—where the International Space Station resides—would come down in a few years without a boost, says Nicholas Johnson, NASA’s chief scientist for space debris. Objects in geostationary orbit—above the dragging effects of Earth’s atmosphere—could take more than 1 million years to fall.
17,300 The estimated number of pieces of debris larger than 10 centimeters in diameter that are being tracked by the U.S. Space Surveillance Network. The SSN also tracks more than 300,000 objects measuring between 1 and 10 cm and billions that are much ...
