astronomical phenomenon: the crossing of the smallest planet of our solar system, Mercury, in front of the solar disk. Mercury, whose orbit will bring it directly between the Earth and the Sun, it will appear like a dark dot -1/150ÏŒ of the diameter of the Sun – crosses slowly over 7,5 hours the brilliant disk of our star.
Something similar had happened in 2006, but the crossing then it was not visible from Greece. It will happen again on November 11, 2019, so it will be visible again from our country, while the next crossing will take place in 2032. On average, in a century happening 13 or 14 crossings of Mercury. The first was noticed by the French astronomer Pierre Κασεντί in 1631, two decades after the invention of the telescope. According to astronomers, the crossing of the 9 May will be visible from Greece for the most part, but the Sun will set an hour before the end of the phenomenon, and so it will not be possible to observe the exit of Mercury from the solar disk. The “input” of the planet to the Sun is expected to take place on 14:12 (cet), so in this first contact, the Mercury will be tangential to the outside of the Sun. After three minutes the planet has now entered a whole and is tangent internally to the solar disk. During the next six hours, Mercury will appear to be “traversing” of the solar disk, reaching to the deepest point of the crossing at 17:57. The phenomenon will end at 21:42, when the Sun has set, so the end of the crossing will not be visible from Greece. The phenomenon will be visible in its entirety from Western Europe, West Africa, as well as the eastern Americas, North and South. Experts point out that the observation of the crossing can only be done with special solar filters on telescopes or binoculars, not with naked eyes or with just sunglasses.
Prolonged observation of the Sun, even when he is low on the horizon, it is dangerous without special filters, otherwise you risk serious and permanent eye damage, even blindness. Mercury completes a full orbit around the Sun every 88 days (the year) and passes between Earth and the Sun every 116 days. But usually the planet seems under or over the solar disk, and not in him.
Because Mercury is the closest planet to the bright Sun, moving at a distance of only 46 to 70 million. km. from this, it is difficult to study with telescopes from the Earth. The temperature on its surface ranges from minus 170 to over 400 degrees Celsius. It rotates so slowly around its axis, that displays the unique peculiarity of the day (one full rotation) is twice the duration of the year (a complete orbit around the Sun). It is a dense planet with an “iron heart” proportionately larger than the core of iron of the Earth, while the surface shows signs of volcanic activity. Up to now, two missions of the American Space Agency (NASA) have visited the planet: the ship “Mariner 10” three times in the two years 1974-75 and the “Messenger” in 2011-15.
The mission BepiColombo the European Space Agency (ESA) and the Japanese Space Agency (JAXA), which will be launched in 2017 or 2018, will reach Mercury in 2024. Anyone who wants, can monitor the passing of Hermes online through the telescope Slooh at: here
Did you know? What phenomenon will be visible from Earth today?
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