06/18/2021 – Ephemeris – Summer* will start Sunday night

This is Bob Moler with Ephemeris for Friday, June 18th. Today the Sun will be up for 15 hours and 34 minutes, setting at 9:31, and it will rise tomorrow at 5:56. The Moon, 1 day past first quarter, will set at 2:41 tomorrow morning.

Summer is just a couple of days away, though we have already been sweltering through a very hot first half of June. Summer will officially arrive for us on Earth’s Northern Hemisphere at 11: 32 pm, June 20th. If you are south of the equator, winter will arrive. If you are listening to this on the Internet, or reading this on my blog, it’s 3:32 UT, June 21st. And to be season agnostic, it’s the June solstice. From the 20th to the December solstice, the first day of winter for we northern hemispherians, (I think that’s a word) the daylight hours will get shorter as the Sun heads south. Solstice means Sun standstill as it stops its northerly motion and will, after Sunday, head back south again. The Northern Hemisphere will still be heating up for another month.

The astronomical event times given are for the Traverse City/Interlochen area of Michigan (EDT, UT – 4hr). They may be different for your location.

* Summer in the Northern Hemisphere only. Winter starts in the Southern Hemisphere.

Addendum

The Sun’s path through the sky on the summer solstice day from Traverse City, MI. The Sun is plotted every 15 minutes. The Sun’s motion is constant. The closeness of the Sun plots at higher altitudes is an artifact of portraying a hemispherical sky on a flat screen. It is a stereographic projection. Created using my LookingUp program.

Earth and magnified local area near summer solstice. Image taken near local noon June 17, 2020. Credit NOAA DSCOVR satellite orbiting the Sun-Earth L1 point 994,970 miles (1,601,432 kilometers) sunward from the Earth.