02/09/2017 – Ephemeris – Tomorrow’s penumbral eclipse of the Moon
Ephemeris for Thursday, February 9th. The Sun will rise at 7:50. It’ll be up for 10 hours and 12 minutes, setting at 6:03. The Moon, 1 day before full, will set at 7:28 tomorrow morning.
Tomorrow evening, clouds willing, we see an odd partial eclipse of the Moon called a penumbral lunar eclipse. What is a penumbra? It’s the fuzzy outer part of a shadow that’s cast when the light source isn’t a pin point. Look at your shadow in the sunlight, especially that of your head. The outline isn’t sharp. That outer fuzziness of the shadow is your penumbra where the Sun isn’t completely blocked., while the dark inner shadow is the umbra, where the Sun is completely blocked by your head. Tomorrow evening the eclipse will actually start before the Moon rises. The Moon should appear pretty much normal until it passes deep into the penumbra of the Earth’s shadow. Deepest penetration will occur at 7:45 pm. Where the upper left part of the Moon will appear dimmer than the rest of it.
Times are for the Traverse City/Interlochen area of Michigan. They may be different for your location.
P1 is the first contact with the shadow and P4 the last. Nothing will be noticed at these times. Only when closest to the greatest eclipse will the part of the moon nearest the inner shadow will show darkening.