The Transit of Venus and Mercury is the name given to the passage of these planets in front of the Sun, creating a small dark spot on the solar face.
The Transit of Venus or Mercury is the name given to the phenomenon that occurs when the orbits of Venus or Mercury coincide with the orbit of the Earth and pass in front of the Sun. When this happens, a small spot can be seen on the solar surface.
This phenomenon began to be observed in the 17th century from the work of the astronomer Johannes Kepler , who used the phenomenon as a basis for some scientific evidence and managed to make it possible to predict its occurrence. The first to observe the transit of Venus were Jeremiah Horrocks and William Cabtree, who saw Venus cross the sky in front of the Sun in 1631. Horrocks was the one who made relevant notes of the phenomenon, which were published posthumously in 1641.
→ Frequency of occurrence
Only the transits of Mercury and Venus can be observed, as the orbits of these planets lie between the Earth’s orbit around the Sun. The occurrence of these phenomena depends on an alignment of the orbits of these planets with the orbit of the Earth. The transit of Mercury is more frequent because of its smaller orbit and shorter translation time (88 days). The last transit of Venus took place in 2012 and the next will not happen until the year 2117.
In the 21st century, thirteen transits can be observed and will present average intervals of eight years from one to the other. Most of them will be visible in Brazil.
→ How to observe the transit of the planets?
It is not necessary to use telescopes to visualize this phenomenon. However, observing the Sun is a dangerous task, given the damage that can be generated in vision. To avoid accidents, observations must be made with the help of filters placed on telescopes, special masks placed on the face, etc. There is also the option of an indirect observation. For this, it is enough to project with the aid of a telescope the image of the Sun in the screen.