(CNN) -- The moon disappeared from view along the U.S. West Coast on Saturday amid a total lunar eclipse.
Images from Seattle, Washington, showed the moon's crescent waning from a Cheshire cat's grin to a shadowy sliver before disappearing entirely in the night sky.
All of the United States was able to see some portion of the event, though the West Coast had "a more complete view" and was able to see the totality -- the time when the Earth's shadow completely covers the moon.
The totality on the West Coast was timed as the moon sets and the sun rises, NASA said. It lasted 51 minutes.
"A lunar eclipse occurs when Earth is directly between the sun and the moon, blocking the sun's rays and casting a shadow on the moon. As the moon moves deeper and deeper into Earth's shadow, the moon changes color before your very eyes, turning from gray to an orange or deep shade of red," the NASA website said.
"The moon takes on this new color because sunlight is still able to pass through Earth's atmosphere and cast a glow on the moon. Our atmosphere filters out most of the blue colored light, leaving the red and orange hues that we see during a lunar eclipse. If there are additional dust particles in the atmosphere, the moon will appear to be a darker shade of red," NASA said.
CNN iReporter Bob Cronk took time-lapse video images of the eclipse from his condo on the 17th floor in Portland, Oregon.
"I thought it was pretty cool," Cronk said. "I really wanted to see it turn red."
Instead, the moon disappeared behind fog.
NASA's Lunar Reconnaissance Orbiter spacecraft, which is orbiting 31 miles above the moon, got a front-row seat to the lunar eclipse, the last of the year, NASA said.
The orbiter was to record how quickly certain parts of the moon would cool off during the eclipse, NASA said.
The next opportunity to view a total lunar eclipse from the United States is April 15, 2014.
CNN's Michael Martinez and Phil Gast contributed to this report.