The harvest moon – the full moon closest to the autumnal equinox on Sept. 22 – rose Friday over Cortez as a crowd gathered for the Montezuma-Cortez High School homecoming game.
The moon officially became full at 1:07 p.m. Friday.
If you needed more than a full moon to get you outside with your eyes and camera on the sky, this full moon is also a supermoon. Maybe. It’s kind of a controversy.
Astronomer Richard Nolle defined a supermoon, and the term has really taken off. Sometimes it seems as if every moon is a supermoon. (If everything is super, nothing is super.) Nolle said that a supermoon is a new or full moon that occurs when the moon is within 90 percent of its closest approach to Earth in a given orbit.
Long story short, Nolle has a list of all supermoons, and so does the former NASA astrophysicist Fred Espenak, but their lists disagree. Espenak’s list includes an extra supermoon in 2016 – this month’s harvest moon. EarthSky has a great explanation on why these lists differ. Strangely enough, Espenak’s list seems to meet Nolle’s original definition more than Nolle’s list does.
Go figure.
If you needed even more of a reason to go sky-gazing, check out the bright Venus (-3.9 magnitude) early in the evening. Looking to the west-south; the bright star Spica was under Venus, to the planet’s left. In the same neighborhood, the reddish Mars and the ringed Saturn in the south-southwestern sky. Both were bright, about 25 degrees up from the horizon, about 7:45 p.m.
In Europe, Africa and Asia the full moon was a bit darker, thanks to a penumbral lunar eclipse that began about 11 a.m. Mountain time.
Europe didn’t need any more reason to look up at the Friday night sky than the penumbral lunar eclipse. In North America, you could still catch all the shadowy eclipse action on slooh.com, with play-by-play and commentary Friday afternoon.
Officially, the eclipse started at 10:54 p.m. Mountain time and ended at 2:54 p.m., noted Espenak. The deepest part of the eclipse was be at 12:54 p.m. Mountain time. This was a deep penumbral eclipse, he said, as it has a strong penumbral eclipse magnitude of 0.9080. It lasted about a half-minute shy of four hours.
What is a penumbral lunar eclipse? It occurs when the moon appears to scoot through the lightest portion of Earth’s shadow. Earthlings must remember that our own planet casts a shadow into space. The center of the shadow is the umbra, so when the moon passes through the umbra, we get partial and total lunar eclipses. In this case, the moon sashays through the penumbra; it’s a weaker, lighter shadow. Think archery target: umbra is the center, and the penumbra surrounds it.
As all eclipses belong to a family or series of eclipses, this event belongs to Saros 147 – a fairly young one that started in 1890 – and the series runs through 3134. Friday’s eclipse was the eighth among 70 events. This was the last penumbral eclipse in the series for about 1,000 years. For the first totally awesome total lunar eclipse in this series, circle June 6, 2449, on your calendar.