Eclipse Could Bring Colorful Cosmic Show

To watch the full lunar eclipse, which is now just hours away, you don't have to do anything special, said George McCluskey Jr., an astrophysicist and professor at Lehigh University.

Just look up. And plan to lose some sleep.

The cosmic event, which is expected to last nearly 3½ hours, will begin a little after 1:30 a.m. here. But it will be more than another hour after that before the full eclipse will become visible, giving the moon an orange or reddish hue, McCluskey said.

A pair of binoculars to view details is "nice," McCluskey said, but not necessary.

The Moon is actually at its highest point in the sky at the time of the winter solstice, making it less likely that an obstacle close to the horizon can block your view, he said.

The only other potential problem is a cloudy sky, which as of 10 p.m. does seem to be a threat to the potential spectacle in this area. The moon has mostly been obscured by clouds since before 9 p.m.

This will be the first time since Dec. 21, 1638 that a full lunar eclipse will fall at the time of northern hemisphere's winter solstice, and apparently, until tonight, the only time it has happened in at least the last 2,000 years. There is no particular astrophysical significance to that, but it is an interesting coincidence, McCluskey added.

A lunar eclipse occurs when the Earth's shadow passes over the Moon. At about 1:33 a.m., that shadow will begin to appear on the eastern edge of the lunar disc, and continue to expand until 2:41 a.m. when the full Moon will be completely in the Earth's shadow. The Moon will stay in that shadow for 72 minutes, according to the NASA website.

The reflection of the sun's rays that we see will not completely go away because the Earth's atmosphere scatters light into space, McCluskey said. That scattered light will give the moon a coppery glow.

The NASA website recommends one moment for all of us to view the celestial show. That would be 3:17 a.m., the moment "the Moon will be in deepest shadow, displaying the most fantastic shades of coppery red."

At 3:53 a.m., the Moon will begin to emerge from the Earth's shadow. The show will come to an end a little past 5 a.m.

A lunar eclipse can happen as often as three times a year, though they are not all full eclipses, McCluskey said. This particular eclipse is the first we have had since February 2008.

Believe it or not, McCluskey said solar eclipses, when the moon casts its shadow on the earth, blocking the sun's rays, are actually more common. However, they are viewed far less often because they typically only affect a narrow band of the Earth's geography, he said.

Lunar eclipses are viewed more commonly because when they occur, they are typically visible over half the planet.