Chasing Comets, Asteroids, and Mysterious Space Objects

Chasing Comets, Asteroids, and Mysterious Space Objects — page 5
Why Study Comets and Asteroids No astronauts have ever visited a comet or an asteroid but in recent decades astronomers have sent many spacecraft to study them Astronomers also use powerful telescopes to learn more about comets and asteroids Telescopes on Earth are often built on mountains and in deserts where the air is clear Other telescopes are in orbit above Earth’s atmosphere where the view of space is clearer still Comets streaking across the sky have fascinated people for thousands of years Ancient peoples saw them as omens or signs that warned of disasters to come It was only natural for people to try to learn more about these phenomena Asteroids on the other hand are smaller and only rarely come close enough to be visible from Earth For that reason they were not even discovered until 1801 Scientists use telescopes to monitor asteroids such as this one and their journeys through space 6