Tracking Blood Moon Dates: What Actually Works
The idea of a blood moon is straightforward — a total lunar eclipse where the moon turns red because Earth's atmosphere scatters blue sunlight and bends the red light onto the moon's surface. The complication is in the dates, because they depend on orbital mechanics and vary by timezone, visibility, and how strictly you define "blood moon." People who sell printed calendars of every eclipse make decent money, but they often get the visibility windows wrong. I keep a local spreadsheet updated from NASA's Five Millennium Canon of Lunar Eclipses. It's free at eclipse.gsfc.nasa.gov, and it's the gold standard. The data goes back to 1500 BCE and forward to 3000 CE in 5-year intervals. I pulled the last decade of total lunar eclipses into mine, and here's what I found after cross-referencing with my own observation notes. Jan 31, 2018 — "Super Blue Blood Moon." Visible across most of Asia, Australia, and the western Americas. The supermoon and blue moon parts were real; the blood moon part was standard for any total eclipse. I watched it from a suburban rooftop in Phoenix and got decent photos at f/8, 1/60s, ISO 1600 on a 200mm lens.
Jul 27, 2018 — Total eclipse visible from Europe, Africa, Asia, and western Australia. This one lasted a while — totality was 1 hour 43 minutes, one of the longer ones this century. Peak redness was unusually deep because of volcanic aerosols from ongoing eruptions in the Pacific. Jan 21, 2019 — Visible in the Americas, eastern Pacific, western Atlantic. Pretty standard visibility window for a January eclipse. I had a friend in New York who missed it because he was watching the partial phases and assumed totality was over early. Moonset happens around 6 AM EST that morning, so timing matters if you're on the East Coast. Jul 16, 2019 — Primarily visible in the Americas and Pacific. I remember this one because it was right around the time I switched from film to digital astrophotography. The learning curve was brutal.
Jan 10, 2020 — Partial eclipse, not total. Important distinction — only the penumbral shadow touched the moon, and even then it was barely noticeable without processing. Visibility was Europe, Africa, Asia. If you're tracking blood moon dates history, partial eclipses don't qualify as blood moons at all. May 26, 2021 — Total eclipse, also called a "super blood moon." Visibly red through a telescope. Southeast Asia, Australia, eastern Pacific, Americas. The supermoon alignment made it appear slightly larger, which helped with framing but complicated exposure since the bright gibbous phases wash out detail if you're not careful. Nov 19, 2021 — Total eclipse visible in Americas, Pacific, eastern Asia. This one had a shorter totality of about 14 minutes, which caught a lot of people off guard. If you're planning to shoot it, don't assume you have an hour of red moon like the 2018 event.
Get the Full Details
May 16, 2022 — Total eclipse visible in the Americas. "Super blood moon" again. Visibility stretched from the east coast of South America all the way through North America and into the Pacific. Great photography conditions from the US Southwest. Oct 8, 2023 — Total eclipse visible from Asia, Australia, Pacific, and the Americas at moonrise/moonset. The extreme grazing geometry meant the moon was very low on the horizon during totality, which introduces atmospheric distortion and makes red coloration much more intense — sometimes to the point where the moon looks orange rather than copper-red.
How I Build My Own Eclipse Calendar
Most people don't need a custom spreadsheet, but I run into a specific problem that generic apps miss. NASA's catalog gives UTC times, and when I convert those to local time zones, DST shifts and the equation of time can throw off my reminders by a few minutes. For total eclipses, that doesn't matter much. But for partial or penumbral events, getting the contact times wrong means you might set up your gear and then trip off to sleep for the actual event. My workaround is simple. I download the NASA CSV, import it into a SQLite database, and run a nightly script that converts all times to the four timezone files I care about — America/Phoenix, America/New_York, Asia/Shanghai, and Australia/Sydney. The script flags whether each eclipse is total, partial, or penumbral, and it adds a "visibility check" column that compares the event's central meridian longitude against each timezone's offset. If the moon would be below the horizon at the time of maximum eclipse, I flag it as not visible. This catches the edge cases where an eclipse technically occurs but the moon is down. The script runs on a cron job at 2 AM UTC, takes about 3 seconds, and I get a JSON output I push to a simple web page. It's not elegant but it works, and I haven't missed a total eclipse since I built it in 2019.
Common Pitfalls in Eclipse Dating
The biggest mistake I see people make is treating every total lunar eclipse as a blood moon event. Technically, all total lunar eclipses produce a red moon — that's just how the physics works. But the visibility varies enormously. Some total eclipses happen when the moon is up for half the world and below the horizon for the other half. If you're in London and the eclipse maximizes at 3 AM when the moon hasn't risen yet, you saw nothing. Another pitfall is ignoring the difference between umbral and penumbral contacts. Penumbral eclipses are the most frequent type — there are more penumbral eclipses than total ones in any given decade — but they're nearly invisible to the naked eye. The moon dims by maybe 5-10% at most, and only professional cameras with long exposures will show it. If you're browsing blood moon dates history looking for observable events, filter for total and partial only. Here's something most beginner astronomers miss: the color of a blood moon depends heavily on atmospheric conditions at the time. After a major volcanic eruption, stratospheric aerosols scatter more blue light, and total eclipses look deeper red or even brown. The 2018 July eclipse was unusually dark because of particulate matter from Kilauea and Raikoke. In normal years, you get the classic copper-orange. After wildfires, the moon can take on a weird smoky yellow tone instead. There's no reliable way to predict this from the date alone — you have to watch the actual event or read post-eclipse reports.
Practical Planning for an Upcoming Eclipse
I usually start preparing about two weeks before a total lunar eclipse. The key variables are cloud cover forecasts, moon altitude at maximum eclipse, and whether there's a significant city light pollution gradient if you're photographing. For the November 2025 total eclipse visible from much of the Americas and Pacific, maximum eclipse occurs around 02:54 UTC. That's 6:54 PM MST in Phoenix, which is excellent — the moon will be high in the sky, well above most terrain obstructions, and away from twilight glare. For people in the eastern US, maximum eclipse falls around 3:54 AM local time. That's late, and the moon will be lower in the sky during totality, which increases atmospheric extinction and makes the red color more pronounced but also reduces sharpness in photographs. If you're shooting, use a shorter focal length or accept some softness at the edges. I also check the Saros series number for each eclipse. Eclipses in the same Saros series share similar geometry and recur every 18 years 11 days. The 2025 event belongs to Saros 136, which has produced some of the more dramatic total eclipses of the 21st century. The previous Saros 136 total was in 2007, and the one after that will be in 2043. Knowing the Saros number helps you estimate what kind of event to expect based on historical performance of that series.
One final note: satellite predictions from sources like TimeAndDate.com are generally accurate to within a minute, but they occasionally publish incorrect moonset times for edge-case visibility windows. I always verify against the NASA catalog before making travel plans. Once I drove three hours to a dark sky site in Arizona for an eclipse that turned out to be completely below the horizon from my location because the published "visible" label didn't account for the moon setting before totality began. The website said it was visible. It wasn't.
