Venus Transit
Posted: May 21 2012 12:48 pm
Okay everyone that wants to do something that can't be done again in your lifetime the Venus Transit is coming up in two weeks. So if you have your set up for observing the sun you can see or photograph this too...
A transit of Venus across the Sun takes place when the planet Venus passes directly between the Sun and Earth, becoming visible against (and hence obscuring a small portion of) the solar disk. During a transit, Venus can be seen from Earth as a small black disk moving across the face of the Sun. The duration of such transits is usually measured in hours (the transit of 2004 lasted six hours). A transit is similar to a solar eclipse by the Moon. While the diameter of Venus is almost four times that of the Moon, Venus appears smaller, and travels more slowly across the face of the Sun, because it is much farther away from Earth. Observations of transits of Venus helped scientists use the principle of parallax to calculate the distance between the Sun and the Earth.
Transits of Venus are among the rarest of predictable astronomical phenomena. They occur in a pattern that repeats every 243 years, with pairs of transits eight years apart separated by long gaps of 121.5 years and 105.5 years. The periodicity is a reflection of the fact that the orbital periods of Earth and Venus are close to 8:13 and 243:395 commensurabilities.
The next transit of Venus will be on 5 and 6 June 2012, and it will be the last Venus transit this century. The prior transit took place on 8 June 2004.
