Looking Up: Seems Like A Blue Moon Since The Last Lunar Eclipse

Jan 29, 2018

Lunar eclipse September 2015.
Credit M. Procell

This week on Looking Up Hal prepares us for the impending total lunar eclipse. 

Set your alarms early for Wednesday, January 31st, because it will be your only chance in 2018, and your first in two years, to see a total lunar eclipse! And we in the West have the best look at it, as the Moon sets for folks east of the Mississippi before the show really gets going.

Remember that there are stages to a lunar eclipse, as the Earth slips between the Sun and the Moon and blocks most of the sunlight from reaching the Moon. First up is the penumbral stage, with some dimming of the light, but the really cool part is the umbral or total shadow part. For us in Colorado, the first dimming occurs around 4:20 a.m., but you won’t notice it for a while with the naked eye. The total eclipse starts at about 5:51 a.m. It lasts about an hour and 16 minutes, and ends about 7:08 a.m., so we won’t see it all in the brightening sky.

A lunar eclipse can only happen during a full moon, so the brightness difference is pretty dramatic. Because the Earth has an atmosphere that bends light around the rocky part, the Moon never goes fully black, but rather is usually a gorgeous deep red color.

There is one other lunar eclipse in 2018, but that one is only visible to folks in Asia, so January 31st is your only shot until 2019. So get up early!

Lunar eclipse April 2015.
Credit M. Procell

If you’d like to take a closer look at the Moon or any of the other wonderful and amazing things in the sky, please visit csastro.org for a link to information on our monthly meetings and our free public star parties.