Similar to an eclipse, they are among the rarest predictable celestial phenomena. The last one for the 21st century occurred on 5/6 June 2012. They are historically of great scientific importance as they were used to gain the first realistic estimates of the size of the Solar System. Observation for the first time in 1639 provided an accurate estimate of the distance between the Sun and the Earth. Answer?
Transit of Venus the last Venus transit of the 21st century; the prior transit took place on 8 June 2004. The previous pair of transits were in December 1874 and December 1882. The next transits of Venus will take place on 10–11 December 2117, and 8 December 2125. 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. Observations of the 1639 transit, combined with the principle of parallax, provided an estimate of the distance between the Sun and the Earth that was more accurate than any other
The Eclipse, or the Courtship of the Sun and Moon The Eclipse, or the Courtship of the Sun and Moon The Eclipse: Courtship of the Sun and Moon (originally L'éclipse du soleil en pleine lune) is a French silent film made in 1907 by director Georges Méliès. A professor of astronomy gives a lecture instructing on an impending solar eclipse. The class rushes to an observation tower to witness the event, which features an anthropomorphic Sun and Moon coming together. The Moon and the Sun lick their lips in anticipation as the eclipse arrives, culminating in a romantic encounter between the two celestial bodies. Various heavenly bodies, including planets and