AST101H1 Lecture Notes - Lecture 4: Metallic Hydrogen, Axial Tilt, Geology Of The Moon

• School: UTSG
• Department: Astronomy & Astrophysics
• Course: AST101H1
• Professor: Ian Shelton

Document Summary

Discovery on march 13, 1781, while continuing a project to chart all stars down to the eighth magnitude, william herschel observed that one of the stars that came into view appeared as a small disk. At first, herschel suspected that the object was a comet, but other astronomers quickly showed that it was a planet orbiting the sun beyond saturn. This was the first planet to be discovered that was not known in ancient times. After herschel"s discovery, astronomers looked through records of previous observations and found some 20 cases where uranus had been seen. However, it had been mistaken for a star, since earlier observers did not have telescopes as good as herschel"s and could not see the disk. Spacecraft exploration nasa"s voyager 2 is the only spacecraft to have visited the planet. Launched in 1977, voyager 2 made its closest approach to uranus on january.