Astronomers have just catalogued the 40,000th near Earth asteroid, a milestone that marks humanity's transformation from passive targets to active defenders of our planet. These space rocks, ranging from house sized boulders to some the size of mountains, follow orbits that bring them uncomfortably close to Earth. Each discovery adds another piece to our planetary defence puzzle, though current surveys have found only about 30 percent of the mid sized asteroids that could still cause regional devastation if they struck our world.
English
Arabic
French
Spanish
Portuguese
Deutsch
Turkish
Italiano
Russian
Romaian
Portuguese (Brazil)
Greek