TIMELINE

1609 First use of the telescope for the systematic study of space.
1781 Discovery of Uranus doubled the diameter of the known Solar System.
1863 Anlysis of starlight shows stars are made of the same elements as those onEarth.

1923 Astronomers observe galaxies other than the Milky Way.

1963 Quasar is discovered.
1987 Supernova.
1987 A explodes.

1999 Hubble telescope sights 18 other galaxies up to 65 million years away.