On June 5, 2012, the planet Venus will move across the face of the sun. Such transits of Venus are among the rarest of planetary alignments, and they come in pairs that are eight years apart but separated by more than a century. Transits of Venus inspire public fascination and scientific activity. Historically, this rare alignment is how scientists have measured the size of our solar system, specifically the distance between the Earth and the sun, which is now identified as the “astronomical unit.” During the 1761 transit, observers noticed a fuzzy halo of light surrounding the dark spot of Venus, visible only when Venus was at the sun’s edge. Scientists of the time concluded that Venus must have an atmosphere, and later scientists confirmed that it does: a dense atmosphere of mainly carbon dioxide with clouds of sulfuric acid.
Dr. Odenwald presented “A Rare Astronomical Event: Transit of Venus” at the Library of Congress in May 2012, and here we offer the slides from his illustrated lecture.
Questions and comments can be posted on the discussion thread on Starship Asterisk.
The original PowerPoint slides are available here: http://spacemath.gsfc.nasa.gov/SED12/TransitVenus2012.ppt
Space Math @ NASA – Transit of Venus 2012 Resources
NASA: 2012 Transit of Venus
Transit of Venus .org
How to Make a Sun Viewer
Local Transit Times
NASA Eclipse Website