Awash in Daylight
Hidden amid the year’s shortest night, the sky beckons
With days upon days of scorching weather already, you might be surprised that summer begins only this week, on June 21, with the summer solstice. On this day, the sun reaches its farthest point north in the sky, 231⁄2 degrees north of the equator directly over the Tropic of Cancer. That morning the sun rises at 5:40 and sets 14 hours, 55 minutes later at 8:35.
Although summer solstice does indeed provide us with the most daylight of the year, it is by no means the hottest time of year; that is still to come. Like a bear slowly waking from hibernation, the bodies of water and the masses of land in the northern hemisphere are much slower to warm than the air. So even though our days grow shorter after Tuesday, the Northern Hemisphere continues to grow warmer in what is called the lag of the seasons. Only after autumnal equinox, when the length of night outpaces that of day, will it begin to cool.
The waning gibbous moon rises in late-evening at week’s end, and by last-quarter phase Wednesday it rises an hour after midnight.
Sunset reveals Saturn high in the south-southwest, the lone evening planet, but don’t confuse its brighter, yellow glow with blue Spica far overhead. Looking at the ringed planet, you may think you’re seeing double, as Saturn pairs with the star Gamma Virginis, or Porrima, just one-quarter degree above. Better yet, Porrima is itself a binary star, distinct when viewed with even a modest telescope aimed toward Saturn.
Saturn sets due west at 2am, and within an hour Jupiter rises due east. Old Jove rises several minutes earlier each night, and by mid-August will appear before midnight. In the lingering darkness just before dawn, scan the east horizon for Venus. Much dimmer Mars hides midway between Venus and Jupiter, more easily spotted with binoculars now but rising higher each night.