Starting just after 10 p.m. Thursday, a slow-rolling space spectacle we haven’t seen in more than two years will make its weird and wonderful return. All we need is a clear sky to marvel at it for hours.
Thursday night marks the first total lunar eclipse visible anywhere on Earth since November 2022. A lunar eclipse means the moon is passing through Earth’s shadow and going temporarily dark. A total lunar eclipse means that darkness will swallow the entire moon, with not even one bright edge or sliver escaping.
It turns out that the Pacific Northwest — well, make that the whole United States — will be ideally placed for eclipse viewing. On the other side of the world, central Asia and India won’t see it at all.
Lucky us: All we need to do is go outside and look up toward the south. You can take a peek at 9 p.m. Thursday, which is when the moon — halfway up the sky — starts slipping into outer zone of the Earth’s shadow, called the penumbra.
IF YOU GO
What: Lunar eclipse telescope viewing with Rose City Astronomers and OMSI (weather permitting). Space science director Jim Todd will give informal talks about the eclipse and the night sky.
When: Starting at 10 p.m. Thursday
Where: Oregon Museum of Science and Industry, 1945 S.E. Water Ave., Portland
Admission: Free
Information: www.omsi.edu/events/omsi-star-party
But there still won’t be much to see for another hour.
Look again at 10:09 p.m., when the moon starts entering the super-dark zone of totality, called the umbra. Over the next hour-plus, a line of darkness will sweep all the way across the lunar surface.
At 11:26 p.m., the entire moon will be inside the umbra. It will start to glow with the eerie orange-red hue of sunlight that’s filtered through Earth’s atmosphere before weakly illuminating the moon. When this happens, it’s known as a blood moon — a genuinely spooky sight.
“The light illuminating the moon during totality comes from the sun’s rays passing through Earth’s atmosphere,” Guy Worthey, an associate professor of physics and astronomy at Washington State University Pullman, said in a bulletin about the eclipse. “If you were standing on the moon, you’d see the Earth surrounded by a ring of fiery sunrises and sunsets from all over the planet. That’s the light that gives the moon its reddish hue.”
Eclipse maximum will be at 11:58 p.m. The moon will stay spookily red inside the umbra for precisely 65 minutes total, until 12:31 a.m. Friday. At that point, it will start exiting totality and its redness will fade. Light will sweep back across the surface. Everything will go back to normal at 1:47 a.m.
“Go outside, look up, and be patient,” Worthey said. “It’s a beautiful and slow-moving event — something you can enjoy over time.”
Weather permitting, the Oregon Museum of Science and Industry and Rose City Astronomers will co-host a free telescope viewing party in the parking lot at OMSI, starting at 10 p.m. Thursday.
If weather doesn’t permit eclipse viewing, a couple of cool NASA videos at science.nasa.gov/resource/total-lunar-eclipse-march-2025 give a good sense of just how weird a blood moon can look.
