It may only be March, but already this year we've had two supermoons to behold. The first, January 21, also featured our total lunar eclipse spectacle. The second, February 19, was the biggest and brightest supermoon of the year.
The third, happening tonight, will be the final supermoon of 2019. March 20 brings the changing of the seasons, as we go from Winter to Spring, so the moon is aptly named the 'super worm equinox moon'.
A supermoon is named such because the full moon phase of the cycle occurs at the same time as the moon's closest pass to earth. Tonight, for example, the moon will be 'at perigee' at 223,300 miles from earth, according to NASA. Within the moon's lunar revolution around the earth, it experiences both perigee (closest to earth) and apogee (farthest from earth) points. Tonight's true moment of lunar perigee will be at 3:47pm. The vernal equinox occurs at 5:58pm; the time at which the sun is directly over the celestial equator. Finally, the moon will be completely full at 9:43pm.
March's full moon is also named the 'worm' moon since the ground is transitioning from frozen to thawed. At that time, we typically see the return of the earthworms to our eco-system.