If you live in North America, you may want to hop out of bed early tomorrow morning and catch sight of the rare "blood moon" accompanying the lunar eclipse.
The total lunar eclipse and the blood moon will be visible around 3 a.m. EDT. This is only the second blood moon visible in the U.S. in the past two years, making the event a rare one, meaning it's a "don't miss" for stargazers.
"It's not that often that we get a total eclipse from the United States; sometimes we go years between getting them," says Slooh Astronomer Bob Berman.
When the moon passes behind Earth and into its shadow, we see it as a lunar eclipse. For this event to happen, though, the moon must align perfectly with the Earth and sun. This occurs every few years, although this year has seen four lunar eclipses. However, multiple lunar eclipses won't occur again within the span of a year for at least two more decades.
A blood moon is an even more rare event and only happens during a full lunar eclipse. Because the moon emanates no light, it is backlit by the sun. The red-orange color associated with the blood moon is actually light being refracted from Earth's atmosphere. The moon starts with a dark orange color during the eclipse, but as it moves deeper into Earth's shadow, it takes on a spooky reddish glow.
North Americans will have front row seats to the spectacle tomorrow, especially those on the West Coast. Those, however, on the other side of the planet will miss the entire event.
The eclipse begins at 2:15 a.m. PDT when the moon begins entering Earth's shadow. That will spread across the surface of the moon, left to right. By 3:25 a.m. PDT, the moon will become red as it is entirely eclipsed by Earth's shadow. This will last until around 4:24 a.m. PDT, with the final stage of the eclipse ending around 5:30 a.m. PDT.
Unlike solar eclipses, lunar eclipses are safe to watch with the naked eye or through a telescope without a filter.
The blood moon is often associated as a sign of the biblical apocalypse and many see it as a sign of foreboding. Most, however, just see it as a wonderful natural event that happens occasionally, reminding us of the many wonders of our solar system and the Universe.
