Tag Archives: planetary astronomy

On This Day…1781

On This Day... 13 March 1781

On this day in 1781 William Herschel discovers Uranus.

Uranus is the seventh planet from the Sun. It is the third largest planet according to its radius and the fourth largest planet by mass in the Solar System.

Uranus is named after the ancient Greek deity of the sky Uranus who according to mythology was the father of Cronus and the grandfather of Zeus.

Even though Uranus is visible to the naked eye just like the five classical planets, it was never recognized as a planet by ancient observers because of its dimness and slow orbit.

Sir William Herschel announced its discovery on13 March, 1781, expanding the known boundaries of the Solar System for the first time in modern history.

Uranus was also the first planet discovered with a telescope. 


On This Day…1977

On This Day... 10 March 1977

On this day in 1977 rings were discovered encircling Uranus. 

Astronomers James L. Elliot, Edward W. Dunham, and Douglas J. Mink confirmed the existence of a planetary ring system around the planet Uranus on 10 March 1977.  A Uranian ring system had been suspected since observations made by William Herschel made in 1789.

A system of 13 rings has been discovered to date. 


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