The following has been Reblogged from : The Weather Network!
On the night of June 20, we will witness an event in the night sky not seen since 1948 – a Full Moon on the same night as the June Solstice.
The solstice occurs at 22:33 UTC, or 6:33 p.m. EDT, on Monday, June 20, when the sun reaches its highest point in the northern hemisphere, marking the start of the northern summer, and its lowest point in the southern hemisphere, marking the start of the southern winter.
Around 12 hours earlier – after sunrise in the eastern half of Canada, but before sunrise in the west, the Moon reaches its fullest, and will still be over 99 per cent illuminated when it rises again, Monday night.
The Full Moon and the Solstice Moon. Credit: NASA Goddard/S. Sutherland
Given that we have a full moon roughly every month (there are times when it skips a February), it may not seem like such a rare thing to have one occur on the same day as the solstice, but it’s a bit more rare than you might think.
The last time these two events lined up for those of us living in much of North America and South America was 68 years ago, on June 21, 1948. If you happened to live eastward from there, however, from Greenland around to the International Date Line, it was actually a little more recent, on June 22, 1967.
The next time it happens after this, again for Greenland and points eastward, is 46 years from now, on June 21, 2062. If you’re in Atlantic Canada, you’ll have to wait until June 20, 2054, when the Full Moon occurs just after midnight, and we reach Solstice later in the day. For the rest of Canada, due to the exact timing, we actually won’t see another one for the rest of this century! We will get to see a rare December Solstice Full Moon on Dec 21, 2094, though.
The reason for this rarity? Although the Full Moon does fall in the range of June 20 to 22 more often than that, the exact date of the June Solstice shifts back and forth in that range too, so that they frequently miss each other.