Venus Transit Half Hoops
A transit of Venus across the Sun takes place when the planet Venus passes directly between the Sun and Earth becoming visible against 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 June 2012 lasted 6 hours and 40 minutes.
Transits of Venus are among the rarest of predictable astronomical phenomena. They occur in a pattern that generally repeats every 243 years, with pairs of transits eight years apart separated by long gaps of 121.5 years and 105.5 years.
The last transit of Venus was on June 5 and 6, 2012, and was the last Venus transit of the 21st century. The next transit of Venus will be in December of 2117.
Venus transits are historically of great scientific importance as they were used to gain the first realistic estimates of the size of the Solar System.