Summer solstice, the longest daylight of the year, occurs on June 21. This is also the shortest night of the year, a sadness for us northerly star gazers. Still, the weather is warm, the lightning bugs twinkle in the trees and bushes, and the summer starscape is quietly beautiful.
A few minutes past 6 PM EDT on 5 June 2012, there will be an astronomical event which will not happen again until 10-11 December 2117. This rare event is a transit of Venus across the Solar disk. A transit is a type of eclipse. But unlike a typical eclipse, where the eclipsing object can block the entire Sun, a transit blocks only a small fraction of the Sun. To learn more about transits in general, and this transit in particular, come to the talk at the Venus Transit Party, or check some of these Venus Transit resources.
Evening Sky: Mars and Saturn are still high in the sky towards the south-west. At magnitude +0.5, they both outshine the nearby bright star Spica in Virgo. Towards the middle of the month, Mercury starts a month-long evening apparition. In the last half of June, Mercury sets about 1.5 hours after sunset, towards the West-Northwest.
Pre-dawn Sky: For those who out before dawn, the morning sky holds some treats. Jupiter has emerged from behind the sun, and will rise about 45 minutes before sunrise at the start of the month. By the end of the month, Jupiter will rise 2 hours before sunrise. Looking East-Northeast about half an hour before sunrise on the 17th, the waning crescent moon will be just to the left and slightly below Jupiter.
That’s all for this month. And, as the great Jack Horkhemier used to say, Keep Looking Up!
Helen Hart, 1 June 2012; references: Joe Spargo’s June Skies article; the Astronomical Calendar, Starry Night planetarium program, USNO Astronomical Data Services.