| Venus will appear against the background of the Sun again This morning is a holiday for astronomers in the Eastern Hemisphere. In this part of the Earth on June 8 you can observe a rare spectacle - the passage (transit) of Venus across the disk of the Sun. The last time scientists had such an opportunity was more than a century ago - in 1882. This time, Venus will be visible against the background of the solar disk for almost 6 hours - from 9.20 to 15.24 Moscow time, and this astronomical miracle can be observed throughout almost the entire territory of Russia. If, of course, the weather permits - when the sky is covered with clouds, you can forget about observations. Just remember: looking at the Sun without eye protection is dangerous, there is a risk of getting a retinal burn and losing your vision. Observations require special equipment; banal dark glasses are unlikely to help here.
From a formal point of view, the passage of Venus is no different from an ordinary partial or total solar eclipse. Only they occur when the Moon appears between the Earth and the Sun. But the apparent size of our planet’s satellite is quite large, and it is capable of almost completely obscuring the solar disk. Venus is located much further from us, and although the diameter of the second planet is comparable to that of Earth, it is not able to organize a full eclipse. From Earth, Venus will be visible only as a small black speck, almost a dot against the background of the bright Sun. Therefore, it is best to view this passage through a telescope equipped with special darkening filters.
Transits of Venus occur, although rarely, but quite regularly. If you cannot see the transit today, then in eight years this phenomenon will repeat. True, we may not wait until the next time - Venus will appear against the background of the solar disk only at the end of 2119.
For the first time, Venusian transits were predicted by the German astronomer Johannes Kepler, who calculated the laws of celestial mechanics. He also calculated the frequency of these passages: in his opinion, paired appearances of the second planet in the sun’s rays should have occurred every 120 years. True, Kepler could not live to see the transit he predicted, which occurred in December 1631. And in Russia, the most famous passage of Venus happened in 1761: as school textbooks say, Mikhailo Lomonosov, observing this phenomenon through smoked glass with his own hands, discovered an atmosphere on Venus. Previously, transits of Venus and Mercury through the Sun were very important for astronomers: these phenomena made it possible to calculate distances between objects in the Solar System with high accuracy. Now the passages of planets have become the object of entertaining astronomy, and scientists are no longer promised great scientific discoveries. However, they play a big role, for example, in attracting the attention of a curious public to the dry science of space.
In addition, scientists now intend to use similar observations to detect planets in other star systems. When such a planet, which cannot be seen even with the help of the most precise instruments, finds itself between a telescope located on Earth and a distant star, the brightness of the latter weakens slightly. If such fluctuations in brightness are observed regularly, then we can not only assume the presence of a large planet, but also calculate the periodicity of its revolution and even try to predict its size. In particular, proposals have been put forward to launch a special satellite into low-Earth orbit that will search for distant planets. Orbital observations of space objects are more accurate due to the fact that flying telescopes are not interfered with by the layer of the earth's atmosphere. So far, however, none of the leading space powers has decided to implement such a project. Vladimir DZAGUTO |
|
