Timeline of Discovery of Solar System Planets and Their Moons

18th century
Date	Name	Image	Other/Permanent designation	Discoverer(s) and notes
1780s
o: March 13, 1781 p: April 26, 1781	Uranus		7th Planet	Herschel first reported the discovery of Uranus on April 26, 1781, initially believing it a comet.
o: January 11, 1787 p: February 15, 1787	Titania		Uranus III	Herschel. He later reported four more spurious satellites.
o: January 11, 1787 p: February 15, 1787	Oberon		Uranus IV	Herschel. He later reported four more spurious satellites.
o: August 28, 1789 p: November 12, 1789	Enceladus		Saturn II	Herschel
o: September 17, 1789 p: November 12, 1789	Mimas		Saturn I	Herschel
Date	Name	Image	Other/Permanent designation	Discoverer(s) and notes

“A day is sometimes our mother, sometimes our stepmother.”
—Hesiod (c. 8th century B.C.)

Timeline of Discovery of Solar System Planets and Their Moons - 18th Century