An eclipse of the Moon is total, in which case our satellite is completely immersed in the Earth’s dark inner shadow (the umbra)—or partial when only part of the Moon is covered. Total eclipses begin and end as partials, as the Moon enters and then leaves the umbra. Our second lunar eclipse this year happens during the early morning hours of November 8th. But seeing it is somewhat of a race across the country as the Moon gets lower and lower in the sky as the spectacle unfolds.
On Tuesday, November 8th, our lovely satellite enters the Earth’s shadow for the second time this year (the previous one being on May 16th). Partial eclipse begins above the western horizon about two hours before dawn on the East Coast and shortly after midnight on the West Coast. Here’s a synopsis of the eclipse phase, time, and altitude in the sky above for a major city on each coast:
Partial Eclipse Begins 4:09 27 degrees
Total Eclipse Begins 5:16 15 degrees
Maximum Eclipse 5:57 7 degrees
Total Eclipse Ends 6:44 Moon just on horizon – sunrise 6:35
Partial Eclipse Ends 7:49 (Daylight – not visible)
San Francisco (PST):
Partial Eclipse Begins 1:09 62 degrees
Total Eclipse Begins 2:16 51 degrees
Maximum Eclipse 2:59 44 degrees
Total Eclipse Ends 3:41 36 degrees
Partial Eclipse Ends 4:49 23 degrees
As can be seen from the above, the further west you live, the better the visibility in terms of the Moon being higher in the sky. In any case, a clear western horizon free of trees, mountains, buildings or other obscurations is essential for a good view. Binoculars are the ideal instrument for watching eclipses, with their low magnifications and wider fields of view being better than the higher powers and limited fields of typical telescopes. Seeing the Moon completely surrounded by lots of sky makes it appear to be floating in space. This impression is additionally enhanced with binoculars since using both eyes gives a sense of depth perception. Any and all sizes of such glasses work just fine!
There are several things to notice during the eclipse. One is that the Earth’s shadow is curved as it falls across the Moon, proving that our planet casting the shadow is round and not flat as long believed. (To their credit, some ancient sky watchers made this connection centuries ago.) Another is the brightness of the Moon during totality which depends on the amount of cloud cover, pollution, and dust and smoke in our atmosphere at that time. This also affects the color seen, which is usually a deep coppery-red in hue. There have been some eclipses (especially following volcanic eruptions) so dark that the Moon was nearly invisible! One additional thing to take note of is where in the sky the eclipse begins—and where it ends. This movement is a result of the Earth itself spinning eastward.
— James Mullaney
Former assistant editor at Sky & Telescope magazine & author of 10 books on stargazing. His
latest, Celebrating the Universe!, is available from HayHouse.com.