The entire eclipse runs from 12:53 to 6:38 a.m. EDT — the wee hours of a Tuesday morning for many residents of the eastern U.S. and Canada and all of South America. You can sleep a little longer by forgoing the beginning penumbral stage and waiting for the onset of the umbral phase at 1:58 a.m. EDT, when the Moon encounters the truly dark part of Earth’s shadow. Want more sleep? After totality, which runs from 3:06 to 4:25 a.m. EDT, the remainder of the eclipse is a reverse of the earlier stages. You can get your fill of totality and then return indoors to a warm, comfy bed (my tactic for this eclipse).
The partial stages of lunar eclipses may be similar, but we never know what to expect during totality. That’s because the eclipsed Moon is aglow with sunlight refracted through Earth’s atmosphere, and its condition can be dramatically different from one eclipse to another. The Moon usually takes on an unnatural coppery red hue, but there are exceptions.
The most amazing lunar eclipse I have ever witnessed was one that occurred during the morning hours of December 30, 1982, several months after an eruption of Mexico’s El Chichón volcano blasted huge quantities of sulfur dioxide and particulates into the atmosphere. During mid-eclipse, the Moon was barely visible to the unaided eye. I could scarcely make out its ghostly form, even when viewing through a 13.1-inch reflector!
As you gaze at the fully eclipsed Moon, imagine for a moment what it might be like to stand on its surface, gazing earthward. You’d be witnessing the spectacle of a total solar eclipse, with Earth serving as the eclipsing body. Our planet’s dark disk, four times wider than the Moon’s, would be encircled by a thin, but brilliant red halo (sunlight refracted by Earth’s atmosphere) that would bathe the lunar surface with an eerie ruddy glow.
If you live in a region untouched by this month’s eclipse or if clouds spoil the event, fear not. A repeat performance October 8 will be observable throughout much of the Pacific area. You can also find a list of the remaining total lunar eclipses for the current decade on this page, courtesy of NASA and Fred Espenak (http://eclipse.gsfc.nasa.gov/lunar.html).
Questions, comments, or suggestions? Email me at
gchaple@hotmail.com. Next month: An astronomical salute to Cinco de Mayo. Clear skies!
