But perhaps few people understand how the basis of this odd idiom is actually grounded in an astronomical phenomenon which, by definition, does not occur particularly often.
This Saturday when you look up at the night sky, to gaze at the stars, make sure to take one good look at the moon, for it's "once in a blue moon".
"A blue moon is a phenomenon where a full moon appears twice in a month".
NASA announces a new discovery of the moon
It might be as simple as having a lunar rover drag icy rocks and soil into a sunlit spot and collect water as it evaporates. This "suggests that water could be much more widespread on the Moon than previously thought", Hayne told AFP.
Offered for a restricted time while supplies last at 20 Denny's restaurants in the Miami-Dade location, the Blue Moons Over My Hammy is a ham and scrambled egg sandwich with Swiss & American cheeses on specifically created blue sourdough bread, then grilled to cozy perfection. According to NASA the next full moon on Halloween isn't expected to happen until 2039. Now let's throw in the fact that for the first time in almost two decades, there will be a full moon on Halloween and you've got yourself something to think about. This past spring we saw a "Full Worm Moon" in March followed by a pink supermoon in April. N Rathnashree who is the administrator of Nehru Planetarium, Delhi confided the interval Blue Moon is a calendrical interval. However, sometimes, a calendar month gets two full moons. When this happens, the third full moon of that season is called a "blue moon".
"This moment is known as the "syzygy" of the Sun-Earth-Moon system, and can happen at any time day or night". "Every time zone has them except those east of (GMT) +8 time zones if they have daylight saving time, or (GMT) +9 with no time of day", says Hunt.
And, when a month has two full Moons, as is the case for October 2020 (we'll have a full Moon on October 1st, which will be the Harvest Moon, and again on October 31st), the second full Moon is referred to as a "Blue Moon". "You can see it in places close to sources of dust, ash and smoke, but in our area, it's close to zero".
Typically, Blue Moons only come once every two or three years.