Summer Solstice – the longest day of the year on June 21!

Summer is officially here as the Summer Solstice heralds it’s beginning on Wednesday at 12:24am! Summer officially begins on this day – so it is time to celebrate!   Here is your guide to the sky for June 19 to 25, 2017…

Sun Stands Still, New Moon, and a change in seasons..

The Summer Solstice marks the longest day and shortest night of the year, and here in the Northern Hemisphere this year it is on June 21 at 12:24 am EDT. On this day, the Sun rises at its position farthest north of east, reaches its highest altitude in the sky at noon, and sets farthest north of west. Ancient cultures knew that the Sun’s path across the sky, the length of daylight, and the location of the sunrise and sunset all shifted in a regular way throughout the year, today we often do not pay as much attention to this, but it is an important part of the march of seasons.

Solstices are astronomical events, caused by Earth’s tilt on its axis and its motion in orbit around the Sun, and we get two per year – summer and winter – which are the extremes of our seasonal cycle.  The reason for these events, and our seasons as a whole is that planet Earth is tilted on its axis by 23-and-a-half degrees. At the June solstice, Earth is positioned in a way which our North Pole is leaning most toward the Sun, the converse is true at the December solstice. All locations north of the equator have days longer than 12 hours at the June solstice. Meanwhile, all locations south of the equator have days shorter than 12 hours.  The farther from the equator you are, the greater the effect.

Summer Solstice celebrations have taken place since antiquity. In ancient times, the date of the June Solstice was used to organize calendars and it also was a popular time for weddings. Stonehenge’s unique stone circle was erected around 2500 BC in order to establish the date of the Summer Solstice. Observers would stand in the center and watch to see the Sun rises over the heel stone on the Summer Solstice. Some Native American tribes such as the Sioux held ritual dances to honor the Sun. Preparations for the event included cutting and raising a tree that would be considered a visible connection between the heavens and Earth, and setting up teepees in a circle to represent the cosmos. Participants painted their bodies in the symbolic colors of red for the sunset, blue for the sky, yellow for lightning, white for light, and black for night.  Many culture in Europe held mid-summer celebration honoring fertility.

Sunrise this week is 4:49 am and sunset at 8:25 pm with the Sun crossing into Gemini at the end of this week.  New Moon takes place on Friday at 10:31 pm and the Moon is at apogee that day as well.

Constellations – Hercules our hero

Over the last few weeks we have explored the constellation of the Summer Triangle getting ready for the season which starts on Wednesday, but what about one of the great hero’s in the night sky, Hercules?  Hercules is a bit faint but the Summer Triangle and Bootes frame this constellation, so look between them for the “keystone” marking his body.  From there you can find the faint arms and legs which seem to be flailing in all directions. Hercules is known for his labors, and a number of them are visible as other constellations in the sky such as Leo the Lion, Hyrda the water snake, and even Draco the Dragon to name a few.  Once you find Hercules use binoculars to see M13 o Messier 13 an exquisite globular cluster in his eastern side.  This faint ball is made up of close to a half a million stars and is one of the largest globular clusters visible in the northern hemisphere.

June 21 at 9:30 pm – star chart by

Planets in the Sky – All but Mars this week!

Mercury is low on the horizon just prior to sunrise this week.  While Venus in Aries rises around 2:40 am and is high in the east at dawn.  Look for it in the constellation of Aries.  Jupiter and Saturn are in the evening sky as bright beacons.  Jupiter is high in the southwest at sunset in Virgo, while Saturn in Ophiuchus is in the southeastern sky.  It starts low in the east at sunset becoming better as the night progresses.  Mars is still lost in the glow of sunset this week.

Celebrate the coming of Summer with some stargazing, check out Hercules, look for Jupiter and Saturn in the evening sky, or bright Venus in the morning before dawn.  Happy stargazing and keep your eye on the sky!

Shawn Laatsch

About Shawn Laatsch

Shawn Laatsch is the director of the Emera Astronomy Center and Jordan Planetarium at the University of Maine. He started his astronomy education career in 1984 and has directed planetariums in university and science center facilities, taught undergraduate astronomy courses, and given numerous lectures around the globe. He serves as President (2017 & 2018) of the International Planetarium Society, Inc. the world’s largest organization of planetarium professionals. Shawn has a passion for sharing astronomy and stargazing with people of all ages.