On Monday sky-gazers in Germany watched the rare spectacle of a Mercury transit in front of the sun. According to the German Weather Service (DWD), the mini solar eclipse was not seen in many places due to clouds and high fog. Especially in East Germany, however, was the opportunity to observe Mercury in his transit.
In Saxony and Brandenburg, the chances had been good and also in Thuringia, Saxony-Anhalt and Western Pomerania you had at least the late afternoon still had the opportunity. To watch you needed a telescope with special sun filters.
During a Mercury transit, the innermost and smallest planet of our solar system passes between the earth and the sun and becomes visible through a telescope as a small point in front of the solar disk. Sun, Mercury and Earth are then roughly in line. Mercury is the sunniest planet. Its circumference is a good 15,000 kilometers - with the earth it is about 40,000 kilometers.
Highlight of the current astronomy year
Mercury transit is rare because Earth and Mercury revolve around the Sun at different speeds, and the levels of their orbits also diverge by several degrees. For comparison: Mercury takes 88 days to orbit around the sun, the earth is good 365. The last Mercury transit was in May 2016. The next will take place in 2032.
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The current event was therefore the highlight of the astronomy year 2019. In many places sky gazers met. Also, observatories opened or offered live streams. In Germany, however, only about half of the Merkur transit was to be seen because it was then dark.
At 1:35 pm, the small planet came to the edge of the sun and, as a black dot, moved almost exactly over the center of the sun. The period of observations ended at sunset, which is currently in Germany between about 16.00 and 17.00 clock depending on the region.
Never look directly into the sun
A Mercury transit can only be observed with a telescope with additional special equipment or via a projection screen. Experts have previously warned against being exposed to the blazing sun unprotected. There is a danger of blindness. With the naked eye, the planet would not be visible in front of the sun anyway.
Mini solar eclipses are rare, not only with regard to Mercury. From Earth's point of view, only Mercury and Venus can pass through the Sun from all the planets in the solar system. Their orbits are closer to the sun. All the other planets orbit the sun at a greater distance than the earth and therefore never pass between it and the central star.