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Lunar Phases

The apparent shapes of the Moon as seen from the Earth, which are caused by the Moon’s orbit of the Earth once every 29.5 days. The same phase will fall on the same date of the year according to the Saros cycle, every 18 years, 11 days, and eight hours. See our moon phases page for more information.


Radio Programs

Harvest Moon Sliding back the Harvest Moon October 5, 2017

Thunder Moon The right Moon for the right season July 8, 2017

Moon and Regulus Sneaking up on the celestial lion — after this. February 10, 2017

Moon and Aldebaran Disappearing in the moonlight December 12, 2016

Moon and Aldebaran Going nose to nose with the bull November 14, 2016

Hunter’s Moon Hunting up the Hunter’s Moon October 15, 2016

Short Moon A short night for the full Moon June 19, 2016

Moon in the Middle Phasing in the crescent Moon June 10, 2016

Good Librations Peeking at the far side of the Moon March 21, 2016

Moon and Companions Circling through the stars March 20, 2016

Christmas Moon Lighting up the night December 25, 2015

Long-Night Moon Rudolph gets the night off December 24, 2015

Hunter’s Moon Marking time with the Hunter’s Moon October 25, 2015

Blue Moon Modern folklore about the night sky July 29, 2015

Moon and Spica Frozen in place in lunar skies July 21, 2015

Short Moon A short night of moonwatching June 30, 2015

Catching the Rain A lunar cup for catching rainfall April 19, 2015

Eclipses Through the Ages A legacy from 1492 April 1, 2015

Harvest Moon The full Moon lights the way September 7, 2014

Moon and Companions Quartering the Moon February 20, 2014

Moon and Aldebaran Peeking at the Moon’s backside January 10, 2014

Long-Night Moon Filling the night with moonlight December 15, 2013

A New Cycle Beginning a new lunar cycle May 23, 2013

Moon and Regulus Lining up some bright moonlight May 16, 2013

Long-Night Moon Lighting up the long night December 26, 2012

Moon and Companions Taking a peek at the Moon’s backside November 9, 2012

Harvest Moon Celebrating the Mid-Autumn Moon September 28, 2012

Blue Moon A “colorful” astronomical rarity August 29, 2012

Moon, Spica, and Saturn Parsing the changes of the Moon May 30, 2012

Annular Eclipse II Cycling through centuries of eclipses May 19, 2012

Moon and Companions Reflections on a quarter Moon January 14, 2012

Featured Images

Full Moon behind the Wisconsin state capitol, September 2015

Bright Moon November 13, 2016

Total lunar eclipse, October 2014

Lunar Eclipse September 26, 2015

Venus, Mercury, and the earthshine-illuminated crescent Moon

Lighting the Shadows May 30, 2014

First-quarter Moon

Moonwatch September 22, 2012