The planet Venus , when moving in orbit every 583.93 days, is between the Sun and the Earth. This configuration is called the “bottom connection”. At such moments, the celestial body can cause partial eclipses, projecting onto the disk of the star. However, the size of the planet Venus is 30 times smaller than the sun. Because of this, when observed through a telescope, a celestial body can be seen against the background of a disk of a star in the form of a small dark circle. However, this phenomenon can be observed without such a device. People can see the passage of Venus through the disk of the Sun even through dark glass. If this planet were in the same plane with the Earth, then this phenomenon would be repeated at each lower connection. However, it tends to an ecliptic of 3.395. Therefore, in the lower connections, the celestial body passes south or north of the sun. This is due to the peculiarities of the movement of this planet. The passage of Venus through the solar disk may be possible if the lower connection should take place near the node of the planet’s orbit.
In the Roman Empire, the Hundred Years Games were held every 110 years. Their motto was: "No one has seen this event before and will never see it again." Such a large gap between the games was chosen so that even the centenarians could not reach the new holiday. The passage of Venus across the disk of the Sun is an extremely interesting event. It happened in 2012 on June 6th. Before that, it happened in 2004. However, it is unlikely that any of those people who have observed this phenomenon will see it again. The passage of Venus across the disk of the Sun is a paired phenomenon. First, there are two summer intersections of the luminary with an eight-year interval, and after that, after 105 years, two winter, also with an interval of 8 years. Further, after 121 and a half years, again paired summer passages occur. The next similar phenomenon will take place in 2117.
Past observations
Nowadays, no one expects great scientific discoveries from the contemplation of the passage of Venus on the solar disk, but in the XVIII century, the scientific world of Europe went on expeditions to distant lands to record these phenomena (1761 and 1769) from different places on the planet. These observations made it possible to know the parallax of our star, the size of the solar system and the distance from the star to the Earth. Lomonosov, thanks to them, was able to determine that Venus has an atmosphere, having made out a thin bright halo near the planetary disk, which arose due to refraction of the rays of the star in atmospheric gas. The passage of Venus across the disk of the Sun in 2012 did not bring any special discoveries.
How to observe such phenomena
Venus’s path through the star’s disk and other events associated with the luminary must be observed through dark glass, which can attenuate intense light. Otherwise, you can seriously injure your eyes. For these purposes, a protective mask of an electric welder is well suited. For observations, it is also possible to use glass smoked on fire or a film folded into several layers, which is illuminated and developed. These accessories are good filters. To safely observe the phenomenon through a telescope, it is necessary to diaphragm its lens somewhere in half, and use dark glass or magnetic disks from old computer disks at the eyepiece.