Blood on the Moon: The Upcoming 2025 Total Lunar Eclipse

You know what we love here at Spacing Out? A total eclipse. Doesn’t matter what kind you’re talking about, one celestial object passing directly in front of another is worth getting excited about in my opinion (what, I’m a space nerd, you expected something else?).

Last year, of course, a nice swath of the US was in the path of a total solar eclipse. What we’ve got coming up in a couple of days is a total lunar eclipse. It’s very different, but also awesome, so let’s go over what is happening when so that you have all the information you need if you happen to be on the right side of the planet for this event!

The How: Solar vs. Lunar Eclipses

Image

Solar and lunar eclipses, while both involving specific geometry of the Sun, Moon, and Earth, are different beasts. You get a solar eclipse when, at the new Moon phase, our Moon’s movement carries it directly between the Earth and the Sun. During this time the Moon’s shadow falls on the Earth. Lunar eclipses occur when, at the full Moon phase, the Moon’s movement puts Earth directly between the Moon and the Sun and Earth’s shadow falls on the Moon. 

If you were fortunate enough to see last year’s solar eclipse, you probably had to travel for it. That’s because total solar eclipses are only visible from small bits of the Earth. Not so with total lunar eclipses. Anyone who is on the nighttime side of the Earth when one is happening (and who has a clear sky—always a requirement) can see it.

This is for the exact basic reason you can probably guess: the Earth is much larger than the Moon. When a solar eclipse happens, you have a smaller shadow falling on a larger object and only part of the larger object actually gets covered by the shadow. In a lunar eclipse, you have a smaller object moving into the shadow of a larger object. Not only does the smaller object get completely covered by the shadow, but it takes some time for it to move all the way across the shadow, which is why lunar eclipses are easier to observe and last a lot longer than solar eclipses.

The Where: Who’s Gonna See It?

Image

Since lunar eclipses happen when the Moon is full, anyone on the nighttime side of Earth can see it. Being on the opposite side of the Earth from the Sun means that the Moon rises about when the Sun sets and vice versa. 

We usually think of full Moon as being an entire night, but it’s actually a single moment: the exact moment where the Moon is opposite the Sun and we see the entire daytime half of the Moon. Total lunar eclipses happen around that moment. For this eclipse, the side of the Earth that will be facing the Moon during the whole of totality will include all of North and South America.

The westernmost bits of Africa and Europe will be able to catch some of totality as the Moon is going down, while the Korean peninsula and bits of easternmost Russia will see an eclipsed Moon rising (which honestly sounds pretty cool). Other parts of Europe, Africa, eastern Asia, and Australia can see bits of a partially eclipsed Moon as it’s rising or setting. More on that in a moment.

The What: What’s It Even Going to Look Like?

It would make sense to assume that the Moon moving into the Earth’s shadow would just look like a line of dark moving across the Moon and then it’s dark and then it starts to emerge from the dark. Of course, things are naturally not that simple. For one thing, the Earth’s shadow has multiple parts. 

Image

The Sun, you may have noticed, is not a point source—it’s a big ol’ ball in the sky. That means that light from different parts of the Sun can still reach the Moon even if part of it is blocked by the Earth. As a result, there is a sort of outer ring to Earth’s shadow called the penumbra where part of the Sun’s light is there. It’s still considered part of the shadow, but it’s a very pale part of the shadow. When the Moon is in the penumbra, it’s hard to notice.

Then, there’s the deep, dark center of the shadow, the umbra. Within the umbra, the Sun’s direct light is entirely blocked by the body of the Earth. If you’re looking at a lunar eclipse, the part where you’re likely to begin to notice is when it begins to move into the umbra. This is when it looks like a line of darkness progressing across the face of the Moon.

Then, when the Moon is entirely in the umbra, you get totality. At this point the Moon appears to turn red. This is because the Moon is cut off from direct light from the Sun, but it’s not cut off from all sunlight because Earth has an atmosphere.

Earth’s atmosphere likes to make sunlight bounce around. It doesn’t make it all bounce around evenly though. Bluer wavelengths of light are easier to bounce around than redder ones. This is why we have a bright blue sky in the daytime—the blue light from the Sun is being scattered around in all directions. At sunrise and sunset, when the sunlight is coming at us from a more extreme angle, it’s the red light that makes it all the way through to our eyes, which is why the Sun looks redder at these times and why the sky reddens (red sky at night, sailor’s delight!).

Image

During a lunar eclipse the Moon can’t see the Sun, but the Earth sure can, including the parts right around its edges (from the Moon’s perspective) which are experiencing sunrise or sunset. For those bits around the edges, that red part of sunlight that makes it through the atmosphere at those times of day is actually able to go all the way through the atmosphere and back into space, all the way to the surface of the Moon. Since it’s the only visible part of the sunlight that will get through, it paints the Moon red.

(Also, from the Moon’s perspective, during a lunar eclipse the Earth would look like an enormous, deep red ring in the sky. We’ve never actually gotten to see a total lunar eclipse from the surface of the Moon, but hoo boy would I love to!) 

Because the Earth’s shadow is so big compared to the size of the Moon, it takes our satellite a while to move through it. Exactly how long depends on what part of the shadow the Moon is hitting. If it’s near the top or bottom, it may only briefly pass through the umbra. If it’s near the center though, the totality part of a lunar eclipse can last for nearly four hours.

Then, as the Moon begins to pass back into the penumbra, the brightness of even a little full sunlight starts to gleam on the edge of the Moon, and the dark line of the umbra begins to retreat across the lunar surface. By the time the Moon is fully back into the penumbra it will look pretty normal to us, though the eclipse technically doesn’t end until it has fully exited the penumbra.

The When: It’s Slightly Complicated

This total lunar eclipse will be happening on the night of March 13/14. Most maps will give the timings in UTC, but I’m going to give them in Eastern and Pacific times for simplicity, since most of the landmass seeing the eclipse will be between those two time zones.

Image

It actually stretches across the end of March 13 into the early hours of March 14. It technically begins at 11:56 pm Eastern/8:56 pm Pacific on March 13, but this is just when the Moon is going to hit the edge of the penumbra. Close observation might reveal the slight darkening, but it’s not going to be very impressive. 

The Moon hits the edge of the umbra at 1:09 am on March 14 Eastern/10:09 pm on March 13 Pacific. This is when the show really starts. The Moon’s steady motion will cause it to take over an hour to fully entire the umbra.

Totality begins at 2:26 am on March 14 Eastern/11:26 pm on March 13 Pacific. The Moon isn’t going through the very center of Earth’s shadow on this pass, so totality will only last about an hour. You’ll see bright light start hitting the Moon’s limb again at 3:32 am Eastern/12:32 am Pacific on March 14.

The good part of the eclipse will end at 4:48 am Eastern/1:48 am Pacific on March 14, when the Moon will fully exit the umbra. It will be in the penumbra for another 75 minutes, but who’s gonna stay up for that part besides diehard astrophotographers? Not this writer, I can tell you that!

The Why: Because It’s Awesome

Seeing the entirety of this eclipse will require staying up pretty late for folks in North and South America, but if you have clear weather you should definitely take advantage! Lunar eclipses may be easier to see than solar ones, but that doesn’t mean the opportunity comes around all that frequently. 

Plus it’s an eclipse! The universe (okay fine, just the solar system, but still!) is putting on a show for you to enjoy! Drink some extra coffee, bundle up nicely, break out the binoculars, and cross your fingers for good weather…you know I will be!

Image