Tomorrow’s the big day. Before most of us go to work in the morning, there’ll be a total eclipse of the moon. Unlike the brief experience of totality during a total solar eclipse, the moon will remain inside Earth’s inner shadow called the umbra for over an hour. The eastern U.S. will only see a partial eclipse because the moon sets before totality. Midwestern observers will see into totality, but the moon will be very low at the time and quite faint in the growing morning light. I urge you to bring binoculars to follow it through as long as you can.
Further west, you’re in the clear with totality in a dark or twilit sky and the moon higher up and easier to see. The total eclipse will also be visible in Australia and across much of Asia. Much of Europe and Africa will not but folks in northeastern Europe in the Scandinavian countries can at least see a partial.
If you’re in the eastern two-thirds of the U.S., Canada and Central America, find a place with a view as low down to the horizon as possible, so you can enjoy the orange-red moon in totality before it fades away in the approaching daylight. Use the chart to prepare your outing. Early birds will see penumbral phase, when the moon is in Earth’s outer shadow and has a strange, grayish cast. Partial eclipse begins with the first dark “bite” from the moon’s upper edge.
If you have a good view of totality, take a minute to estimate the moon’s appearance using the Danjon Scale (left). L=0 is a very dark eclipse; L=4 a bright one. I’ll pass that information along to an atmospheric expert. The moon’s color and brightness can tell us a lot about the clarity (or lack thereof) of the atmosphere.
I hope skies are clear (and not too cold!) for you. Dress warmly. My favorite warm clothes include bomber hat, insulated boots and a neck gaiter. Get ready to experience one of astronomy’s most deeply moving cosmic alignments: Sun, Earth, moon. And you! Please send your photos and reports, and I’ll include them in a blog tomorrow.