Transits of Venus are so rare because the planet's orbit is tilted just over three degrees from the plane of the solar system. This means that most of the time Venus passes above or below the sun's disk, as seen from Earth. On average, we see four transits of Venus within 243 years. The events happen in pairs spaced eight years apart, and they alternate whether Venus crosses the top or the bottom of the solar disk. This year, for instance, the planet will transit the top of the sun.
Astronomers first used telescopes to observe a transit of Venus in 1639. But it wasn't until 1769 that dozens of scientists scattered across the globe to make detailed measurements of the event, including the famous voyage of British lieutenant James Cook, who had astronomers collecting transit data from the island of Tahiti during his South Pacific expedition.
I lack the special solar filters needed for safe viewing through a camera so my only chance was to try and capture the sun as it set. For fun, I stood in roughly the same spot where I photographed the solar eclipse bracketed by some cottonwood trees.
|Transit of Venus as viewed from Dallas Texas June 5, 2012|
|Passenger jet passing in front of Transit of Venus, plane was approaching DFW Airport|
Under The Bridge Downtown
|White Ibis Flock taking flight near the Continental Street Viaduct with Downtown Dallas in the background June 5, 2012|
Showdown at the water hole
Only a five minute mountain bike ride from the Katy Trail but a world away. This time of year UT Southwestern hosts a large population of wading birds in a rookery located near a parking garage. The adult birds fly the half mile-mile or so from UTSW to the Trinity to feed.
Moonrise Over The Margaret Hunt Hill Bridge
This particular alignment of the moon only happens in early-mid June and again to a lesser extent 28 days later in late June or July.