Astronomers expect a colorful show Saturday night when Earth's shadow falls on the Moon, creating a total lunar eclipse. The event is expected to be much more visually pleasing than a similar eclipse May 15.

For those able the see the entire eclipse, a fuzzy outer shadow, called a penumbra, will first fall gradually on the Moon, as Earth gets directly between the Sun and the Moon. At around 6:30 p.m. ET a stark scallop will be carved from the Moon as Earth's primary shadow, the umbra, takes over.

The Moon will go into total eclipse at 8:06 p.m. ET and emerge from totality 25 minutes later.

That's a relatively short period of totality, due to the fact that the Moon is passing nearer to the bottom of a circular slice of a cone-shaped shadow presented by Earth, rather than across the very center of the circle.

You can imagine tracing a short line with your finger across the bottom of a dinner plate, just through the outer reaches of the mashed potatoes, versus a longer line that would traverse the turkey in the middle, too, as well as the cranberry sauce on the other side.

Those with fairly dark skies will be able to see the Moon, vaguely, even during totality. It is expected to take on an orange or reddish color as light from all the worlds sunsets and sunrises is bent through Earth's atmosphere and falls on the lunar surface, then is reflected back to Earth. To picture this, imagine standing on the Moon during this event: An astronaut there would see the Sun eclipsed by Earth, with a reddish halo created by light being bent through the atmosphere of the home planet.

Because the Moon is near the edge of the shadow, the coloring effect should be greater than what occurred during the May 15 eclipse. The Moon may take on the sort of blood-red hue that frightened the ancients.

SPACE.com's Night Sky Columnist, Joe Rao, figures it will turn coppery red during totality.

"This eclipse has all the makings of being a rather colorful event," Rao said.

Eclipses occur only during full Moons. Because the Moon's plane of orbit around the Earth is tilted compared to Earth's path around the Sun, not every Full Moon generates an eclipse. There can be as many as three in any given year. Some years there are none.

During the total phase of the eclipse, those under otherwise dark skies away from city lights should notice a distinct darkening of their surroundings as more stars emerge in the sky.

Residents of the Western U.S. and Canada -- about one-third of each country -- will need a clear view of the horizon to see the eclipse, in progress as it rises. The Moon will come up in the East, as it always does, opposite the glow of the setting Sun.

A lunar eclipse can be enjoyed with the naked eye. But optical aids offer the chance to better investigate craters on the Moon and the subtle shading and coloring of the eclipse.

"All you'll really need are your eyes," Rao said. "But binoculars or a telescope will give a much nicer view."

If you plan to watch more than just a few minutes of the eclipse, seasoned observers recommend dressing warmer than you think necessary and bringing food and hot drinks. A chair or blanket will make the experience more enjoyable.

All evening in the southern sky, Mars shines brightly, an obvious beacon that typically has an orange or yellowish cast. Mars is brighter than any star in that part of the sky. Stretch your arm out and make a fist. Now count four fist-widths to the right of the Moon and you'll see Mars. That's about 40 degrees of separation, as astronomers count it.