A Red Moon Will Star in Tonight’s Total Eclipse

A total lunar eclipse expected to create views of a blood-red moon will be visible tonight throughout most of North America -- weather permitting.

Tonight’s event is the only eclipse -- solar or lunar -- visible from nearly all of North America this year, said Fred Espenak, an astronomer at NASA’s Goddard Space Flight Center in Greenbelt, Md. (A partial solar eclipse Oct. 14 was visible from some parts of Alaska.)

Such an ideal viewing opportunity will not occur again until 2008, astronomers note.

The only area in North America that won’t catch the entire eclipse is western Alaska.

In the Pacific time zone, the total eclipse phase will occur from 7:23 p.m. until 8:45 p.m. The partial eclipse, which starts at 6:14 p.m., will not be visible from the West Coast because the moon will not have fully risen yet. The eclipse will be over by 9:54 p.m.

“The moon should have a deep red color during the total [eclipse] phase,� Espenak said.

Because the bottom edge of the moon will dip so much deeper into Earth’s shadow than the top, there should be a variation in brightness across the moon to look for during the event.

Lunar eclipses take place only during a full moon and occur when the moon passes through some part of Earth’s shadow.

In a total eclipse, the entire moon passes through Earth’s shadow. The result can be an orange, red or brown moon and occasionally a gray one.

“The strange light on a totally eclipsed moon is the combined illumination from all the sunrises and sunsets ringing the Earth at the time,� according to Sky & Telescope magazine.

The brightness of the eclipse is also affected by weather and the amount of dust in the atmosphere.