On Sunday, May 15, Albertans can see a red moon, or maybe no moon at all. Neither an illusion, nor an atmospheric effect, the rare celestial event is a total lunar eclipse, the first to be seen in Alberta this year.
For Albertans, the partial phases of the lunar eclipse will already be in progress as the moon rises.
A lunar eclipse occurs when the moon travels through the Earth’s shadow in space, and only with the right alignment between the sun, the earth, and the moon. During the eclipse, the moon will enter the earth’s dark (umbral) shadow, taking on a dark red or rusty appearance. Although no direct sunlight reaches the moon during the umbral eclipse, the moon is illuminated by a small amount of long wavelength (red) sunlight refracting through the earth’s atmosphere. After the partial (umbral) eclipse ends, the full moon of May, known as the flower moon, will again be shining in the night sky.
Unlike a solar eclipse, the upcoming lunar eclipse requires no special viewing equipment, and is entirely safe to watch with the naked eye. Telescopes and binoculars will offer greater details of the moon but are not required to view a lunar eclipse. Since the moon will already be rising before the eclipse begins, a location that provides an unobstructed view of the Southeastern horizon will offer the best views.
The upcoming lunar eclipse is weather dependant and may not be visible in overcast skies.