June solstice full moon

http://earthsky.org/astronomy-essentials/june-solstice-full-moon-in-2016

By Bruce McClure in Astronomy Essentials | June 20, 2016

Watch for a full-looking moon on the eve of the June solstice (June 19, 2016) and a full moon on the solstice itself (June 20). From what we’ve been able to gather (sources below), this is the first full moon to fall on the June solstice since the year 1967, which some recall as the year of the Summer of Love, a social phenomenon centered on San Francisco, London and other places around the globe. There’ve been a number of near misses of full moons on June solstices, however. And we are indeed talking about the June solstice, not solstices in general. In fact, there was a full moon eclipse on the December solstice in 2010.

Reliably, the phases of the moon recur on or near the same calendar dates every 19 years. It’s the “or near” that causes the full moon to miss the solstice on that 19th year, sometimes. Nineteen years from this year’s solstice – on June 20, 2035 – the full moon will not fall on the same date as the June solstice. It’ll be another near miss, with the full moon falling on June 20, 2035, and the solstice arriving one day later.

It appears as if the full moon and June solstice won’t fall on the same calendar date again until June 21, 2062.

Be aware that, as we’re figuring all this, we’re using Universal Time (UT or its variant UTC), what used to be called Greenwich Mean Time. Universal Time is the favorite of astronomers because it applies to Earth as a whole. What if we used other time zones? Well, for instance, if we use U.S. time zones, the last full moon and the June solstice actually coincided on June 21, 1986.

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There’s something else special about this full moon, in addition to its falling on the solstice. It marks the fourth of four full moons in between the March 2016 equinox and the June 2016 solstice. Usually, there are only three full moons in one season (between an equinox and solstice, or vice versa), but sometimes there are four.

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