Driftless Dark Skies: Solstice Full Moon

June 8, 2016 by John Heasley

photo by NASA

photo by NASA

We get to enjoy a Full Moon on the Summer Solstice this year on June 20.  A Solstice Full Moon is a relatively rare event happening about once every 19 years.  The exact moment of the solstice is 5:34 pm.  That’s when Earth’s axis is tilted exactly towards the Sun.  You’ve already noticed how this has led to longer days.  On the Winter Solstice we were down to just over nine hours of sunlight.  Now we have almost 15 ½ hours.  The Sun is tracking higher in the sky, rising more in the northeast, and setting more in the northwest. 

It’s the opposite for the Full Moon in the summer.  It is only visible for 10 hours, tracks low in the sky, rises in the southeast, and sets in the southwest.  Because the Moon is lower in the sky, its light passes through more of our atmosphere.  The blues get scattered while the yellows reach our eyes giving the moonlight more of a golden color—honeymoon! 

Besides Honey Moon, this month’s moon is also known as the Rose Moon (because they start blooming) and the Strawberry Moon (because they are so fresh and tasty here in the Driftless Area).  The Ho-Chunk, who have long made this area home, call it Mąįna’ųwira (Earth Cultivating or Hoeing Moon).  The Moon is 100% full at 5:04 am on June 20, so it should appear equally full the evenings of the 19th and 20th.  Watch for it rising in the southeast on Sunday at 7:55 pm, setting in the southwest on Monday at 5:48 am, and rising again on Monday in the southeast at 8:47 pm. 

Jupiter, Mars, and Saturn are all bright and beautiful this month.  Look for Jupiter in the southwest after sunset.  It’s brighter than any star and does not set until after midnight.  Mars is closer to Earth than it has been for 11 years.  Watch for its amber color in the south as the sky darkens.  If you can get a look through a telescope, you should be able to see the polar cap and other surface features.  Saturn is just to the east of Mars and a paler shade of yellow.  Its rings are magnificent through a telescope.  The red supergiant star Antares is just below Mars and Saturn.  I think of it as the beating heart of the Scorpion. 

The Waxing Crescent Moon is just below Jupiter on June 11 and the Waxing Gibbous Moon is nicely clustered with Mars and Saturn on June 16-18.  Enjoy the many moons over our Driftless Area. 

John Heasley is an astronomy educator and stargazer who enjoys connecting people with the cosmos. He volunteers with NASA/JPL as a Solar System Ambassador. For more information about stargazing in southwest WI, like Driftless Stargazing LLC on Facebook and find out whenever there’s something awesome happening in the skies. Driftless Dark Skies appears monthly in the Voice of the River Valley.