CONTENTS NOT JUST ANOTHER STAR 4 UNIQUE URANUS 8 RINGS AROUND URANUS 12 MOVING AROUND THE SUN 14 SPINNING SIDEWAYS 16 MOONS 20 VOYAGER 2 EXPLORES URANUS 24 BACK TO THE ICE GIANTS 28 GLOSSARY 30 FOR MORE INFORMATION 31 INDEX 32
4 NOT JUST ANOTHER STAR At its brightest the planet Uranus is just barely visible to someone on Earth looking up at the night sky So ancient astronomers could see Uranus but they could not tell that it was a planet In contrast the planets Mercury Venus Mars Jupiter and Sat urn are easily seen shining in Earth’s night sky to someone who knows where and when to look Astronomers could tell that these bright objects were planets by the way they moved People on Earth can barely see Uranus marked in green above without using a telescope
5 The planet Neptune was discovered after Uranus in 1846 That was less than two hundred years ago What else might we discover in another two hundred years THINK ABOUT IT After the telescope was invented in the early 1600s Uranus was seen several times Those who spotted it though thought Uranus was just another star Then in 1781 an English astrono mer named William Herschel discovered what he thought was a curious star or per haps a comet This unusual object soon proved to be a planet Uranus William Herschel built his own tele scopes using very large mirrors to ob serve the night sky
