Eclipses, Occultations and Transits

An eclipse is the result of the total or partial masking of a celestial body by another along an observer's line of sight. Solar eclipses result from the Moon blocking the Sun relative to the Earth; thus Earth, Moon and Sun all lie on a line. Lunar eclipses work the same way in a different order: Moon, Earth and Sun all on a line. In this case the Earth's shadow hides the Moon from view. An occultation occurs when a celestial object is eclipsed by the Moon or another solar system body. A transit is either the act of one celestial body passing in front of another or the time at which a celestial object is highest in the sky. The time at which a celestial object crosses the meridian is called the transit time.

Radio Programs

A New Cycle Beginning a new lunar cycle Friday, May 24, 2013
Annular Eclipse A ring of fire above the Pacific Ocean Thursday, May 9, 2013
Moon and Spica Illumination from a disappearing act Thursday, February 28, 2013
Epsilon Geminorum A star by the numbers Thursday, January 17, 2013
Feeble Eclipse Earth casts a feeble shadow on the Moon Tuesday, November 27, 2012
Solar Eclipse Diving into a natural wonder Monday, November 12, 2012
Eclipse Watcher Risking life and limb for a solar eclipse Sunday, August 19, 2012
Cloudy Skies A cruel twist of nature Saturday, August 18, 2012
Solar Spotters Getting a better bead on the Sun Wednesday, June 6, 2012
Venus Transit II A last-in-a-lifetime event Tuesday, June 5, 2012
Venus Transit Measuring out a solar-system ruler Monday, June 4, 2012
Partial Lunar Eclipse Taking a “bite” out of the Moon Sunday, June 3, 2012
Celestial Geometry A hubbub over celestial geometry Saturday, June 2, 2012
Transit and Eclipse Lining up with Earth and the Sun Friday, June 1, 2012
Annular Eclipse II Cycling through centuries of eclipses Sunday, May 20, 2012
Annular Eclipse A ring of fire in the afternoon sky Saturday, May 19, 2012
Happy Coincidence A beautiful scientific coincidence Friday, May 18, 2012
Clockwork Eclipses Ticking off the hours until a solar eclipse Thursday, May 17, 2012
Balloon Ride Taking a balloon ride for science Saturday, April 7, 2012
Rings of Uranus A dark discovery for a giant planet Thursday, March 8, 2012

Featured Images

Solar eclipse of August 19, 1887, from near Berlin
Fire in the Sky Saturday, August 18, 2012
June 5, 2012, Venus transit from International Space Station
Seeing Spots Saturday, June 9, 2012
Diagram of Venus transit of June 5, 2012
Sun Spot Monday, June 4, 2012
Partial lunar eclipse of June 4, 2012
Lunar Nibble Saturday, June 2, 2012
Illustration of annular eclipse of May 20, 2012
In the Zone Friday, May 18, 2012

FacebookTwitterYouTube

©2013 The University of Texas McDonald Observatory