Spring officially arrives on Wednesday with a rare lunar phenomenon known as a “full worm super moon,” the third and final full super moon of 2019.
Weather permitting, the moon will appear slightly larger in the sky on Wednesday night, according to NASA. The full worm super moon should be visible a few hours after the official start to spring.
The first day of spring
Spring will start at 5:58 p.m. Eastern Time on Wednesday with the vernal equinox, when the sun’s light shines evenly over the Earth’s equator. Day and night are divided into roughly equal 12-hour cycles on the day of the equinox, which ends with the sun moving to shine more on the Northern Hemisphere. Daylight hours in the Northern Hemisphere grow longer every day afterwards, until the solstice on June 21.
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The worm moon
The term “worm moon” is typically given to the first full moon in March, according to the Old Farmer’s Almanac. The name signals the spring thaw that releases earthworms frozen in the ground. The first full moon is also sometimes called the “sap moon,” because it heralds the start of the maple syrup season.
“Historically, Native American and other traditional names for full moons were used to track the seasons,” the Almanac says on its website.
Month-specific names for the full moon often capture additional attention when they coincide with other lunar events. In January, for instance, there was a super blood wolf moon, and in February, there was a super snow moon.
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“Wolf” and “snow” are the names for the first full moons of January and February, respectively. Other names include “strawberry” for June, “sturgeon” for August and “cold” for December.
The second full moon in any month is always referred to as a blue moon.
The super moon
The moon’s size appears to fluctuate slightly in the night sky because it orbits the Earth on an elliptical loop. It looks slightly larger when it’s at the closest point, or perigee, of its orbit, according to NASA. Astronomers use the terms “super moon” or “perigean moon” when the moon is full and at the closest point in its orbit.
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NASA says a super moon appears 14 per cent larger and 30 per cent brighter than a regular full moon, although the difference is hard to see with the naked eye.
Wednesday will be the third and final full super moon of 2019. However, it won’t be a blood moon like the two that occurred earlier this year, because it will not coincide with a lunar eclipse.
What colour will the super moon be?
The moon’s colour will be unaffected by any solar or lunar phenomena, so it should look normal.
WATCH BELOW: ‘Super blue blood moon’ appears in January 2018
The moon last appeared to change colour in January, when a lunar eclipse created a red “blood moon” effect on the full super moon in the Western Hemisphere. The colour-change is affected by sunlight interacting with dust particles and clouds in Earth’s atmosphere, according to NASA.
Pollution can also affect the apparent colour of the moon in some parts of the world.
Astronomers are expecting three new super moons later this year, on Aug. 1, Aug. 30 and Sept. 28. The moon will be at its closest point to the Earth on these days, but it will not be visible because it won’t be reflecting sunlight.
The next full super moon will be in March 2020.