00:00Lunar eclipses, especially total lunar eclipses, are really exciting sky-watching
00:08opportunities for astronomers, families, really all enthusiasts around the world.
00:14What can people looking to see an eclipse expect to see?
00:19Well, during a total lunar eclipse, during totality, the moon turns this copper-red color.
00:26It's weird, and it's beautiful and unusual, and it's caused by light refracting through
00:33the atmosphere of the Earth. So if you're on the moon, you're seeing every sunrise and sunset all
00:40around the Earth, and that light sort of filters into the shadow. It's a way for the Earth to sort
00:46of reach out and touch its nearest neighbor. Definitely. So it might be more colorful than
00:54people are expecting. Yeah, exactly. And the color can vary from one lunar eclipse to another.
00:59It depends on how close the moon is to the center of the shadow. It depends on how much dust and
01:07aerosols and all kinds of things are in the Earth's atmosphere. And it's something that amateur
01:13astronomers can participate in, sort of rating the darkness of the moon and the color of the moon,
01:20because that gives us some insight into what causes the color. We don't fully understand it.
01:27So in that we can't fully understand it, it seems that we also can't fully expect
01:33exactly what's going to happen, but we have a general idea of what we're going to see.
01:37That's right. So it's hard to predict. I mean, we know some of the factors like depth in the shadow,
01:44but we don't know exactly what stuff in the atmosphere, the Earth's atmosphere,
01:49creates some of that color. So the more we observe these and the more we record them and are careful
01:56about, you know, deciding what color it is, the better we'll be able to understand and maybe predict in
02:00the future what color they'll be. Definitely. So how long do lunar eclipses typically last,
02:08and why do they last so much longer than solar eclipses? Well, the Earth's shadow is so much
02:14wider than the moon's shadow. Yeah, the great thing about lunar eclipses is that, you know,
02:20an entire half of the Earth can witness them. It's just the nighttime half gets to see,
02:24gets to see it. You don't have to be in a very specific place the way you do with a solar eclipse.
02:32And, you know, with the shadow being as wide as it is, the eclipses will vary depending on whether
02:40the moon is is just skirting the edge of the shadow or going right through the center of it.
02:46So and maybe the inconvenient part of a lunar eclipse is that it happens at night and sometimes
02:52it's early in the morning and it's three o'clock in the morning and you're like, I don't know if I
02:56want to do this. But I think it's always worth getting up to see. Every time I have an opportunity
03:03to see one, I'm up no matter what time it is. Absolutely. Now, I'm curious, this is a little
03:08bit of a more oddball question, but could you predict what a lunar eclipse might look like from
03:15the surface of the moon? Actually, Apollo 12 witnessed something very much like a lunar eclipse.
03:23The space capsule passed through the Earth's shadow. And you may know that Alan Bean was became a
03:30painter after he came back to Earth and he painted this several times. Alan's paintings are sometimes
03:36kind of impressionistic. So the colors are more interesting than the reality. But
03:42what he captured was the brilliant ring of bright sunrises and sunsets, how bright that is, how
03:52visually interesting that is. I think it would be great if we had astronauts on the moon to witness
03:58this. Also during Apollo 15, there was a plan to use the camera on the rover to watch a total lunar eclipse.
04:09It was going to happen a couple of weeks after the astronauts left. But one of the one of the gears
04:16that allowed the camera to point wasn't working after they left. And so we missed that opportunity.
04:22But it's a, you know, it's a, it would be a cool reason to go back just to be there during a lunar
04:28eclipse and see what the Earth looks like. Definitely. Now, so the rover, you know, the rover's camera,
04:34things didn't go according to plan, but we do still have spacecraft orbiting the moon. There's
04:40China's Changi 4 rover still on the moon. What might these spacecraft see during an eclipse? Like what,
04:47what might it look like to them? I, well, I work with Lunar Reconnaissance Orbiter and it's a solar
04:53powered mission. So one of the, one of the aspects of a lunar eclipse for LRO is that its power gets
05:00turned off basically. You know, LRO orbits the moon every two hours. It goes through night time
05:06every 45 minutes. So there's a battery on board and that kind of gets it through the night side and,
05:11and then it charges back up. But during lunar eclipses, a lot of times it'll come around from
05:16the night side and the sun still isn't there. So it has to run on battery power for, you know,
05:21a couple of extra hours. And so LRO has to make preparations for that. Usually most of the instruments
05:28get turned off. Um, and the things that they leave on are like the heater, um, something important to
05:35keep all the stuff from freezing. Uh, but it's a, it's a challenging sort of operational thing that LRO
05:42does. So it's not, it's not having the same kind of fun that we have on the earth. It's,
05:48it's actually having to protect itself. Um, yeah. So I don't, I don't know of any, um,
05:55any missions like LRO that have actually turned to the earth during an eclipse and taken a picture
06:00of it. Cause I think that would be really cool. Uh, I'd like to see it. Right.
06:06Definitely. Um, so I, I just have one more question for you, you know, leaving it off on something fun
06:11to you. What's the most amazing part of watching a lunar eclipse?
06:17Well, I always, I mean, I'm a little biased because I work with moon data all the time.
06:22Um, so I'm always going outside and sort of looking up and, and spending at least a couple
06:26of seconds and contemplating the moon and, and what it means. But a lunar eclipse is such a
06:31spectacular visual event that you get caught up in it. Um, you know, during the partial phases,
06:37you see the moon sort of getting slowly eaten away, um, over the course of maybe an hour,
06:42an hour and a half. And then suddenly it's, it's quite a bit darker, but it's also this deep red
06:48color. And, and you're like, it's a, it's a chance for you to sort of think about your place in the,
06:55in the cosmos, you know, this, this alignment of the sun and the earth and the moon, um,
07:00um, spending a, just a, a little bit of time thinking about how amazing that is and how cool
07:07it is. And you are in a very specific place to be able to see it. Um, you know, aside from just
07:13the visual beauty of it, I, I'd like thinking about that aspect of it.
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