European observations

European observations - William Herschel discovered two...

Info iconThis preview shows page 1. Sign up to view the full content.

View Full Document Right Arrow Icon
European observations (17th–19th centuries) Robert Hooke noted the shadows (a and b) cast by both the globe and the rings on each other in this drawing of Saturn in 1666. Saturn's rings require at least a 15-mm-diameter telescope [105] to resolve and thus were not known to exist until Galileo first saw them in 1610. [106] [107] He thought of them as two moons on Saturn's sides. [108] [109] It was not until Christian Huygens used greater telescopic magnification that this notion was refuted. Huygens discovered Saturn's moon Titan; Giovanni Domenico Cassini later discovered four other moons: Iapetus , Rhea , Tethys and Dione . In 1675, Cassini discovered the gap now known as the Cassini Division. [110] No further discoveries of significance were made until 1789 when
Background image of page 1
This is the end of the preview. Sign up to access the rest of the document.

Unformatted text preview: William Herschel discovered two further moons, Mimas and Enceladus . The irregularly shaped satellite Hyperion , which has a resonance with Titan, was discovered in 1848 by a British team. [111] In 1899 William Henry Pickering discovered Phoebe , a highly irregular satellite that does not rotate synchronously with Saturn as the larger moons do. [111] Phoebe was the first such satellite found and it takes more than a year to orbit Saturn in a retrograde orbit . During the early 20th century, research on Titan led to the confirmation in 1944 that it had a thick atmospherea feature unique among the solar system's moons....
View Full Document

Ask a homework question - tutors are online