May 2020

Phases of the Moon

Mercury - Meeting with Venus

Mercury is on May 4th behind the Sun and then moves quickly to the east of Sun. In the last decade of May, it begins its visibility near the north-western horizon. In contrast to its visibility in February 2020, this time the planet Venus and our Moon help in finding Mercury about one hour after sunset. About 10 degrees over the NW horizon, Venus moves westward while Mercury moves eastward. They meet on May 22 with the angular distance of only 1.2 degrees! Moreover, on May 24, the very thin Moon will be also nearby. Use binoculars to see this nice and rare events. The greatest eastern elongation (i.e., the maximal angular distance from the Sun) reaches Mercury on June 4.

Venus - End of the Snow

The planet was for several months the brightest object on the western sky after sunset (of course, not counting the Moon). But now it moves towards the Sun (in angular sense), its visibility at the evening gets shorter and shorter and its brightness decreases from (-4.&) mag down to (-4.0) mag. in the last week of May, Venus sets down in bright sky short after the sunset. In the telescope, one can observe that the illuminated part of Venus rapidly decreases, too: from 24 per cent on May 1st to only 2 per cent at the end of month. However, since Venus moves towards our Earth at the same time, its angular diameter rapidly increases during May!