Heads up, sky watchers! On March 21st, the appearance of the last in the Supermoon trifecta this year happens Thursday, which also coincides with the much-awaited change of seasons.

This change of seasons is signaled by the March (Vernal) Equinox.This marks the beginning of Spring in the Northern Hemisphere and Autumn in the Southern Hemisphere.What happens on this day is that, the Earth’s axis is neither tilted towards nor away from the Sun, resulting in aroughly equal duration of day and night in all areas of the Earth (approximately 12 hours).

During this period, the Sun lies perpendicular to the Earth’s equator, and it will appear to rise and set exactly from due east and west, respectively. At the Equator, the Sun will be directly overhead at noon. The March Equinox will begin at 1:58 AM (UAE Time), when the Sun directly crosses the celestial equator. Following the Equinox, daytimes will gradually become longer in the Northern Hemisphere, while night times will begin to get shorter in the Southern Hemisphere.

Diagram illustrating Earth’s Orientation during the March Equinox (Image Credit: eclipsegeeks.com)
Satellite Imagery of Earth at March Equinox (Image Credit: EUMETSAT)

Coincidentally, astronomy enthusiasts, particularly the selenophiles, will be dazzled by the beauty of the last Supermoon for this year. The term Supermoon is just a colloquial term for the full Moon at perigee, or when the Earth’s natural satellite is at its closest distance tothe planet. At roughly 100% illumination, the Moon will appear slightly bigger (7%) and brighter (14%) than a typical full Moon. The full Moon will be at approximately 359,400km away, less than its average distance of around 384,400km from Earth.

Bet you’re wondering why the last Supermoon is called a “Super Worm Equinox Moon.”Well, according to the Farmer’s Almanac, the full Moon in March is also known as the Full Worm Moon. The Native Americans began calling it that way because of the worms that start to surface from the soil, signaling a shift in the temperature as seasons begin to change.

There will not be another “Super Worm Equinox Moon” until 2030.

The Full Moon taken from Al Sadeem Observatory last February 20, 2019 (Image Credit: Al Sadeem Astronomy)
A comparison of ordinary full Moon with a Supermoon, or a full Moon at perigee (Image Credit: AldrinGabuya/Al Sadeem Astronomy).