Latest / Daniel and Kelly’s Extraordinary Universe / What is Zodiacal Light?

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What is Zodiacal Light? · Daniel and Kelly’s Extraordinary Universe

• 0:01
  Speaker 1: Hi, It's Jorge and Daniel here. And this holiday season,
• 0:03
  Speaker 1: if you're looking for a gift for yourself, for a friend,
• 0:06
  Speaker 1: or for your your family, why not get him the
• 0:09
  Speaker 1: gift of Answers about the Universe. So check out our
• 0:11
  Speaker 1: new book Frequently Ask Questions about the Universe. You can
• 0:14
  Speaker 1: find details at universe f a q dot com. Thanks
• 0:18
  Speaker 1: for supporting the podcast. Happy holidays everyone, he or Hey?
• 0:29
  Speaker 1: What words come to mind when you look up at
• 0:32
  Speaker 1: the night sky? M? I don't know, maybe a celestial
• 0:36
  Speaker 1: cosmic clear, crisp. You never think like dusty or dirty?
• 0:41
  Speaker 1: What what do you mean like space is dirty? Yeah?
• 0:44
  Speaker 1: Actually space turns out to be super dusty, and that
• 0:47
  Speaker 1: dust doesn't even stay up there in the sky. There
• 0:51
  Speaker 1: are literal tons of space dust falling on Earth every day. Man,
• 0:56
  Speaker 1: are you saying the universe is like a slob? I know, right? Like,
• 0:59
  Speaker 1: come on, Universe, clean up your mess, Universe. It's like
• 1:01
  Speaker 1: a bad roommate. At least you have someone else to
• 1:04
  Speaker 1: blame for your house being dusty. We need to get
• 1:06
  Speaker 1: like a space vacuum mega made. Wait, isn't the space
• 1:11
  Speaker 1: already in a vacuum? How can it be dusty? I
• 1:29
  Speaker 1: am or Hammy cartoonists and the creator of PhD comics.
• 1:31
  Speaker 1: H I'm Daniel. I'm a particle physicist and a professor
• 1:34
  Speaker 1: at you see Irvine, And I like getting a little
• 1:37
  Speaker 1: bit of space dust in my eye. Oh yeah, you'd
• 1:39
  Speaker 1: like to sprinkle a little space magic in your face?
• 1:43
  Speaker 1: Everyone's in a while. Well, you know, we all are
• 1:45
  Speaker 1: made of star dust, and so it's just sort of
• 1:47
  Speaker 1: like a reunion between these little bits of matter that
• 1:50
  Speaker 1: might have burned inside a star billions of years ago
• 1:53
  Speaker 1: and been missing each other ever since. Wow, doesn't make
• 1:56
  Speaker 1: you like tear up literally and literally when you think
• 1:59
  Speaker 1: about space dust literally? Also, I think dust just gains
• 2:03
  Speaker 1: a whole new kind of level when you put the
• 2:05
  Speaker 1: words star in front of it. Like if you say
• 2:07
  Speaker 1: we're made at a star dust, that sounds awesome. But
• 2:10
  Speaker 1: if you say we're made out of dust, usually don't
• 2:12
  Speaker 1: want that until after you die. Does that work for
• 2:15
  Speaker 1: other things like star trash? Does that sound exotic and fantastic?
• 2:18
  Speaker 1: Star dirty dishes, star chores? There you go, I'll send
• 2:25
  Speaker 1: that to my kids. You don't just have chores, you
• 2:27
  Speaker 1: have star chores. Then maybe we should get your star
• 2:30
  Speaker 1: kids to do it. They say they are stars. There
• 2:33
  Speaker 1: are stars in my world. But welcome to our podcast
• 2:36
  Speaker 1: Daniel and Jorge Explain the Universe, a production of Our
• 2:39
  Speaker 1: Heart Radio in which exploring the universe is not a
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  Speaker 1: chore but a great joy because we cast our minds
• 2:45
  Speaker 1: out there into the deep universe, through the clouds of
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  Speaker 1: gas and dust, penetrating into everything that's out there and
• 2:51
  Speaker 1: trying to get an answer for you answers about the biggest, deepest, oldest,
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  Speaker 1: most important questions in the universe. How big is everything,
• 3:00
  Speaker 1: what's it all made out of, how does it all work?
• 3:02
  Speaker 1: Can it possibly make sense? And what is the latest
• 3:06
  Speaker 1: crazy thing that we have learned about the universe? Wit?
• 3:09
  Speaker 1: Are you saying that my allowance doesn't depend on me
• 3:11
  Speaker 1: doing this podcast? Depends on which allowance you're talking about.
• 3:17
  Speaker 1: Do I get paid anyways? That doesn't sound right. Either
• 3:20
  Speaker 1: do the podcast or do the dishes? So which is
• 3:22
  Speaker 1: more fun? Do the dishes? Anyways? But anyways, Yeah, you're right.
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  Speaker 1: It is a huge universe full of oxperious things and
• 3:30
  Speaker 1: a lot of interesting things to discover and learn about.
• 3:32
  Speaker 1: Because the universe is a surprising place all the time.
• 3:35
  Speaker 1: It's surprising us with new truth new ways in which
• 3:38
  Speaker 1: it works, but only sort of if we get to
• 3:40
  Speaker 1: see it right, only if we get a good view
• 3:42
  Speaker 1: of what's going on out there. And it's an amazingly
• 3:45
  Speaker 1: good view that we have. It's incredible how far you
• 3:48
  Speaker 1: can see out into space. You know, if you stand
• 3:51
  Speaker 1: on the top of a mountain and you can see
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  Speaker 1: fifty miles a hundred miles, you think, wow, this is
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  Speaker 1: instagram worthy. Well, you are sitting on top of an
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  Speaker 1: earth size mountain. Look how billions and billions of light
• 4:02
  Speaker 1: years into space. They can give you a bit of
• 4:04
  Speaker 1: vertigo sometimes if you think about it. But it's really
• 4:07
  Speaker 1: the best view in the universe. Yeah, And it's not
• 4:10
  Speaker 1: just a nice view. It's like a three sixty all overview, right,
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  Speaker 1: Like it's it's up and down, left and right all
• 4:16
  Speaker 1: over in every direction. We can see out millions and
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  Speaker 1: millions and millions of miles away. Yeah, almost every direction.
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  Speaker 1: I mean, the Earth isn't transparent. It would be pretty
• 4:24
  Speaker 1: cool if the Earth was like made of glass, so
• 4:26
  Speaker 1: you could see in every direction. At the same time.
• 4:29
  Speaker 1: That sounds like an episode idea, Daniel, What if the
• 4:31
  Speaker 1: Earth was made out of glass? That sounds like an
• 4:33
  Speaker 1: episode of Black Mirror? Should you throw stones at it,
• 4:36
  Speaker 1: but the stones would mean at a glass too. But
• 4:39
  Speaker 1: if somebody turned the earth in the glass and then
• 4:40
  Speaker 1: we would have no night and be pretty hard to sleep.
• 4:42
  Speaker 1: So maybe that wasn't such a great idea. Well, I
• 4:44
  Speaker 1: guess what I mean is like, you know, people in
• 4:46
  Speaker 1: Australia are you know, also getting a pretty good view
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  Speaker 1: of the universe, and we're getting pretty good view, and
• 4:51
  Speaker 1: when Europe are getting pretty good view, it's like we're
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  Speaker 1: surrounded by infinite emptiness, almost in crystal clear emptiness in
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  Speaker 1: all directions. It is pretty amazing. And we even look
• 5:00
  Speaker 1: looking out at the sky for a long time, right
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  Speaker 1: for thousands and thousands of years, proto humans probably looked
• 5:05
  Speaker 1: up at stars and wondered what they are. And these
• 5:08
  Speaker 1: days we have a pretty good picture for what most
• 5:11
  Speaker 1: of what we're seeing is. The thing that's sort of
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  Speaker 1: incredible is that there's still stuff out there that we
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  Speaker 1: don't really understand. Yeah, it's pretty amazing that you think,
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  Speaker 1: after all this time of looking up, you know, with
• 5:21
  Speaker 1: powerful telescopes and incredible spacecraft that go out there to
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  Speaker 1: explore it, there might still be things that we don't
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  Speaker 1: fully understand about what's out there. And where it comes from. Yeah,
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  Speaker 1: and not just things that scientists can see through their
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  Speaker 1: powerful telescopes, things that you can see with your eyeballs,
• 5:38
  Speaker 1: naked eye observations. Some of those things we still don't understand. Yeah,
• 5:42
  Speaker 1: So to be on the podcast, we'll be asking the
• 5:44
  Speaker 1: question what is zodiacal light? Now? Did I pronounce that correctly?
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  Speaker 1: Zodical or zodiacal? You say zodiacal, I'll say zodiacal. Let's
• 5:58
  Speaker 1: call the whole thing off and go have some tomatoes
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  Speaker 1: and tomatoes. I think of it as zodiacal because I
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  Speaker 1: think it comes from the zodiac zodiac, right, But zodiac
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  Speaker 1: zodac has the emphasis on the Oh, so wouldn't be
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  Speaker 1: zodical light, does it? Though? I say zodiac, not Zodiac.
• 6:14
  Speaker 1: You say zodiac zodiac And welcome to a podcast about linguistics. Well,
• 6:20
  Speaker 1: maybe they should be a podcast episode about the Zodiac killer.
• 6:23
  Speaker 1: Those are very popular, those crime podcasts. Isn't he the
• 6:26
  Speaker 1: Senator for Texas? Right now? We'll say no more, will
• 6:30
  Speaker 1: say no more about the star State. But rearrenting ourselves
• 6:34
  Speaker 1: back up to the night sky. I do think it's
• 6:36
  Speaker 1: really pretty awesome that there are things you can see
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  Speaker 1: out there with your naked eye that scientists are still
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  Speaker 1: trying to figure out. It means that you know, there
• 6:43
  Speaker 1: are still puzzles out there. There's still things that are
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  Speaker 1: huge and big and obvious that have mysteries behind them. Yeah,
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  Speaker 1: and like you say, you don't need a big telescope
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  Speaker 1: to see this big mystery, this zodical light. It's something
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  Speaker 1: you can see with their naked eye almost every day, right. Yeah,
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  Speaker 1: technically it's kind of hard to spot, but if you
• 6:59
  Speaker 1: know where a look, you can see it. So it's
• 7:02
  Speaker 1: a's kind of an interesting thing. I've never heard of
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  Speaker 1: this before. I have to say I was a little
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  Speaker 1: puzzled when I got the outline for this, but it's
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  Speaker 1: pretty interesting and it's kind of a big mystery, that's right,
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  Speaker 1: And it's an active area of research, and amazingly it
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  Speaker 1: even connects to popular music. All right, let's get into it.
• 7:18
  Speaker 1: But first we were wondering how many people out there
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  Speaker 1: had heard of this idea, this concept is phenomenon of
• 7:23
  Speaker 1: the zodical light, and so Daniel went out there to
• 7:26
  Speaker 1: ask people on the internet if they have heard of
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  Speaker 1: the zodical light. So those of you out there on
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  Speaker 1: the internet, maybe doing your dishes, right now. Who would
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  Speaker 1: like to participate for future episodes of the podcast. It's easy.
• 7:37
  Speaker 1: Just write me a message to questions at Daniel and
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  Speaker 1: Jorge dot com. I'll send you the questions back and
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  Speaker 1: you can record your answers in the privacy of your
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  Speaker 1: own home, with or without the sounds of dishes. So
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  Speaker 1: think about it for a second. If you were talking
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  Speaker 1: to a physicist, what would you guess is zodical light?
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  Speaker 1: Here's what people had to say. If I received this
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  Speaker 1: question from somebody else, then you, I would think something
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  Speaker 1: about Virgo or something. But this is coming from from you.
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  Speaker 1: I don't know what to answer right now. My guests
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  Speaker 1: of what zodiacal light or zodiacal light is would be
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  Speaker 1: maybe the light from space that doesn't consist of man
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  Speaker 1: made objects, so our original mapping of the stars before
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  Speaker 1: we started, including satellites and whatnot, Light that comes from
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  Speaker 1: the Zodiac constellations, Light that comes particularly from constellations or
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  Speaker 1: things of that nature. I mean that the zodiacs stars
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  Speaker 1: are real, guests, right there is there light special and
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  Speaker 1: surely not that just the arbitrary star, don't they Zodiac?
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  Speaker 1: I believe that's the twelve constellations that rotate throughout the year.
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  Speaker 1: Hence astrologists say things like the sun is in verbo.
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  Speaker 1: Maybe zodiacal light is light coming from objects that are
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  Speaker 1: in the Earth's orbital plane and therefore obscured by the time.
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  Speaker 1: All right, pretty interesting answers. Most people, I guess connected
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  Speaker 1: it to the like we said, the zodiac or as
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  Speaker 1: you pronounce the zodiac. Now you're making me self conscious
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  Speaker 1: about it. It's in the stars, Daniel, Oh no, this
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  Speaker 1: is not going to become an astrology podcast that made.
• 9:29
  Speaker 1: That might make us more popular if we start protacting
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  Speaker 1: people's features. I for see more physics in your future
• 9:33
  Speaker 1: than me too. Me too. I'm not sure that's a
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  Speaker 1: prediction or a curse. Well, I'm guessing it. It's sort of.
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  Speaker 1: It's related to the zodiac, like the zodiac signs, right,
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  Speaker 1: which are the constellations like Leo and what are some
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  Speaker 1: of the other constellations Gemini, Cancer, Yeah, all those exactly.
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  Speaker 1: But you're not a big fan of constellations, right, I've
• 9:54
  Speaker 1: heard you rant about them before. Constellations are fun to
• 9:57
  Speaker 1: look at, but they're not really astronomy because when you
• 10:01
  Speaker 1: look at constellation in the sky, it's totally just an
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  Speaker 1: artifact of where we happen to be in space. Like
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  Speaker 1: the stars and the constellation aren't clustered together in the universe.
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  Speaker 1: Sometimes some of them are very close and so other
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  Speaker 1: ones are like deep, deep, deep in space. It just
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  Speaker 1: happens to be from our perspective that they make a
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  Speaker 1: specific pattern. They're not really anything astronomical. They have no
• 10:20
  Speaker 1: meaning or information, but you know, they are a way in.
• 10:22
  Speaker 1: They are like people look at the stars and they
• 10:25
  Speaker 1: look at these constellations. It's sort of a way in.
• 10:27
  Speaker 1: But to me, it's a little bit like you know,
• 10:29
  Speaker 1: teaching people about meteorology and starting with the Greek gods
• 10:32
  Speaker 1: of weather or something. Well, this is when I feel
• 10:36
  Speaker 1: like it's a little bit different, because you know, the
• 10:38
  Speaker 1: constellations were part of astronomy at some point in human history, right,
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  Speaker 1: like there were a way for humans to start mapping
• 10:45
  Speaker 1: the night sky or like keeping track of how things
• 10:47
  Speaker 1: were moving in the night sky. Yeah, I'm not really
• 10:49
  Speaker 1: sure that's astronomy. I mean, it's definitely important for navigation
• 10:52
  Speaker 1: and for understanding where you are on the Earth and stuff,
• 10:55
  Speaker 1: But you know, astronomy like the study of the universe
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  Speaker 1: and the stars and trying to understand what's really going
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  Speaker 1: on out there. I don't know. The constellations don't really
• 11:02
  Speaker 1: play a big role in that in my opinion, but
• 11:04
  Speaker 1: you know, of course they have historical importance and there
• 11:06
  Speaker 1: are what a lot of people like to look at it,
• 11:08
  Speaker 1: you know, when you look up at the night sky
• 11:09
  Speaker 1: and spot them. That part is fun, right, and they
• 11:11
  Speaker 1: determine your future. You're just baiting me, just baiting me,
• 11:16
  Speaker 1: just skeptic because you're an aries, right, I'm not even
• 11:19
  Speaker 1: in aries, As if that made any difference. I almost
• 11:25
  Speaker 1: got you there. No, you're trying to pay me into
• 11:27
  Speaker 1: the anti fun corner. It's definitely fun to look at
• 11:30
  Speaker 1: the constellations and to think about this stuff, just you know,
• 11:33
  Speaker 1: don't confuse it with actual science. Well, and actually sort
• 11:35
  Speaker 1: of a red herring because the article light has almost
• 11:38
  Speaker 1: nothing to do with the constellations, right, that's right, almost
• 11:41
  Speaker 1: nothing to do with the constellations, except that it appears
• 11:45
  Speaker 1: along the ecliptic, this plane of rotation of the Solar system,
• 11:49
  Speaker 1: you know, the plane that the planets are on, and
• 11:50
  Speaker 1: the Earth moves around that which is sort of aligned
• 11:53
  Speaker 1: in the sky where we see the planets, where the
• 11:56
  Speaker 1: Sun moves along for example, is what we call the ecliptic. Oh,
• 12:00
  Speaker 1: zodiacal light or the zodiacal light appears along the ecliptic,
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  Speaker 1: and you know, which is also where a lot of
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  Speaker 1: constellations appear. And so I think that's why it's called
• 12:09
  Speaker 1: zodiacal light. Oh right, yeah, because I guess our entire
• 12:13
  Speaker 1: Solar system is on a disc. Right, All of the
• 12:15
  Speaker 1: planets that we know are on a disc, and so
• 12:17
  Speaker 1: on the night sky, they all follow the same line, right,
• 12:20
  Speaker 1: I've never sort of thought about it too hard before. Yeah,
• 12:23
  Speaker 1: planets should definitely fall in a line. Like if you're
• 12:25
  Speaker 1: looking up in the night sky and you see three
• 12:27
  Speaker 1: bright objects that are not in a line, then they
• 12:29
  Speaker 1: can't all be planets because they all are in a disk,
• 12:32
  Speaker 1: you know, and we are on that disc. Also, you
• 12:34
  Speaker 1: always see them line up and it's roughly the same
• 12:37
  Speaker 1: line that the Sun moves along. Oh interesting, Yeah, they
• 12:40
  Speaker 1: all sort of follows the same line, like the like
• 12:43
  Speaker 1: the beads on a string. Yeah, And so that's super
• 12:45
  Speaker 1: cool to think about because it gives you like a
• 12:48
  Speaker 1: three D perspective where we are in the Solar system.
• 12:50
  Speaker 1: It's easy to imagine sort of things moving across our
• 12:54
  Speaker 1: sky as if they're sort of like on a screen.
• 12:57
  Speaker 1: But if you make like a mental switch, you can realize,
• 12:59
  Speaker 1: I'm looking out and being when things are at different distances,
• 13:02
  Speaker 1: and I'm really seeing a three D view of this
• 13:05
  Speaker 1: incredible cosmic object, the Solar system, right, and I'm seeing
• 13:10
  Speaker 1: like bits of it that are further and further away.
• 13:12
  Speaker 1: It's really it's kind of incredible. Can make you almost
• 13:14
  Speaker 1: fall over when you realize that the scale of the
• 13:16
  Speaker 1: thing that you're looking at. And so maybe step us
• 13:18
  Speaker 1: through this what is then zodical light or zodiacal light,
• 13:23
  Speaker 1: And I'm guessing it's something then that happens in the
• 13:25
  Speaker 1: plane of the Solar system. Yeah, exactly. Now people are
• 13:28
  Speaker 1: familiar with like the Northern lights or the Southern lights.
• 13:32
  Speaker 1: That's caused when high energy particles hit the atmosphere and
• 13:35
  Speaker 1: then spiral up to the North pole or the South
• 13:38
  Speaker 1: pole because of the magnetic field. And you can only
• 13:40
  Speaker 1: really see those if you're sort of pretty far north
• 13:43
  Speaker 1: or pretty far south, because that's where those particles end up.
• 13:46
  Speaker 1: But the zodiacal light is pretty cool because you don't
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  Speaker 1: have to be in the north pole or the South pole,
• 13:51
  Speaker 1: or even pretty far north or south to see it.
• 13:52
  Speaker 1: You can see it from almost anywhere on the Earth,
• 13:55
  Speaker 1: and it's actually most visible near the equator in the
• 13:58
  Speaker 1: tropical regions. And what it looks like, it's sort of
• 14:00
  Speaker 1: a cone of light, like a hazy bright pyramid. It's
• 14:04
  Speaker 1: not very crisp, it's not as colorful. It's sort of
• 14:07
  Speaker 1: white that appears above the sunrise or the sunset point.
• 14:11
  Speaker 1: So you can see it just like just after the
• 14:13
  Speaker 1: sun has set or just before the sun is going
• 14:15
  Speaker 1: to rise. I see, so like as the sun is
• 14:17
  Speaker 1: dipping down below the mountains, as it dips down below
• 14:21
  Speaker 1: sort of the horizon and over the mountains that you're
• 14:23
  Speaker 1: looking at, you'll suddenly see like a column or like
• 14:26
  Speaker 1: a huge pyramid of light above it. Yeah, and it
• 14:28
  Speaker 1: happens after the sun is already past the horizon. So
• 14:32
  Speaker 1: you see the sunset, you see the after glow, etcetera,
• 14:35
  Speaker 1: all that red beautifulness, and then before the dark night
• 14:38
  Speaker 1: really kicks in, you see this glow, this pyramid. And
• 14:42
  Speaker 1: I wouldn't say it's like sudden. It doesn't just like
• 14:44
  Speaker 1: pop into your sky. You know, it's sort of as
• 14:47
  Speaker 1: the sun is fading, this is sort of what's left
• 14:50
  Speaker 1: interesting and you know, people can look at this up
• 14:52
  Speaker 1: on the internet and do a Google image search of
• 14:55
  Speaker 1: zodical light and they can get some pretty impresive pictures.
• 14:58
  Speaker 1: They're pretty beautiful. Yeah. Some those pictures obviously taken by
• 15:01
  Speaker 1: like professional photographers and ideal conditions after years of practice,
• 15:04
  Speaker 1: So you can also see some amateur photographs. You could
• 15:07
  Speaker 1: also just sort of have seen it and not really
• 15:10
  Speaker 1: realized it because it can kind of look a little fuzzy.
• 15:12
  Speaker 1: You can look just sort of like a smear of
• 15:14
  Speaker 1: light and you might have imagined, oh, it's just like
• 15:17
  Speaker 1: light from a city over the horizon, you know, light
• 15:19
  Speaker 1: pollution from a nearby football field or something. Right, but
• 15:22
  Speaker 1: it's pretty concentrated, right, Like, it has a particular shape, right, Like,
• 15:26
  Speaker 1: it's not like a semicircle or it's not doesn't take
• 15:29
  Speaker 1: over half of this guy. It's like, you know, right
• 15:31
  Speaker 1: where the sun sort of dips below the horizon, you
• 15:34
  Speaker 1: see this sort of column, triangular column of light. Yeah,
• 15:37
  Speaker 1: and it happens that the ecliptic is like at ninety
• 15:40
  Speaker 1: degrees to your horizon, it's going to be straight up
• 15:42
  Speaker 1: and down if the ecliptic is slanted, because you know,
• 15:44
  Speaker 1: at a different time of the year, then it's going
• 15:47
  Speaker 1: to be slanted along the ecliptic really sort of points
• 15:51
  Speaker 1: the direction that the planets will appear on. Well, yeah,
• 15:54
  Speaker 1: because I guess if you're in the equator, then you're
• 15:56
  Speaker 1: looking at the sunrise and sunset pretty close to the
• 16:00
  Speaker 1: plane of the Solar system, right, But if you're maybe
• 16:03
  Speaker 1: the closer to the north pole, it's going to be
• 16:05
  Speaker 1: kind of tilted, right, yeah. And it also depends on
• 16:08
  Speaker 1: the season, right, because the earth tilt relative to the
• 16:11
  Speaker 1: plane depends on sort of where we are in our
• 16:13
  Speaker 1: orbit around the Sun, and so the ecliptic tilts more,
• 16:17
  Speaker 1: for example, in the winter and summer than it does
• 16:20
  Speaker 1: in the spring and fall if you're in the northern hemisphere,
• 16:23
  Speaker 1: but if you're in the southern hemisphere is the opposite exactly.
• 16:26
  Speaker 1: So what this thing looks like depends on the time
• 16:28
  Speaker 1: of year, and that makes it sort of easier and
• 16:30
  Speaker 1: harder to see. At different times of year. When it's
• 16:33
  Speaker 1: slanted over really really far, it's harder to notice because
• 16:35
  Speaker 1: it doesn't rise it's high above the horizon. So it's
• 16:38
  Speaker 1: easiest to notice when it's sort of like the sharpest
• 16:41
  Speaker 1: angle with the horizon because then it rises further above
• 16:45
  Speaker 1: the horizon and you can more easily spot it. Well,
• 16:47
  Speaker 1: how people google search this and look up images of
• 16:50
  Speaker 1: it because it's pretty interesting. But what sort of one
• 16:52
  Speaker 1: important clue about it is that it doesn't come from
• 16:54
  Speaker 1: the Earth. Like when you look at the sunset or
• 16:57
  Speaker 1: sunrise and you see the beautiful red sky and and
• 17:00
  Speaker 1: the beautiful sort of cloud patterns, that's all stuff that's
• 17:04
  Speaker 1: happening on Earth, in our atmosphere, right, the red shift
• 17:07
  Speaker 1: of the light. But this the fact the zodical light,
• 17:09
  Speaker 1: it's is actually happening outside of Earth, right, It's in space. Yeah,
• 17:13
  Speaker 1: it's really cool because, as you say, it's not something
• 17:16
  Speaker 1: caused by our atmosphere. You know, sunsets and sunlights are
• 17:19
  Speaker 1: red because our atmosphere tends to scatter the blue light,
• 17:23
  Speaker 1: and so during sunrise and sunset, it's that red light
• 17:26
  Speaker 1: that's getting to you, getting to your eyes. So that's
• 17:29
  Speaker 1: an effect of our atmosphere. And even the northern lights
• 17:32
  Speaker 1: and the Southern lights are effects of our atmosphere. There
• 17:35
  Speaker 1: are the solar wind and cosmic radiation raining down on
• 17:38
  Speaker 1: our atmosphere and glowing here on Earth. But the zodiacal
• 17:41
  Speaker 1: light is something else, it's something different. It comes from
• 17:44
  Speaker 1: outer space. As you say, it's something that you could
• 17:47
  Speaker 1: see even on a planet with no atmosphere. It's out
• 17:49
  Speaker 1: of this world alien. It's extraterrestrial for sure. Are you
• 17:55
  Speaker 1: saying the zodiac are aliens? Daniel, boy is gonna be
• 17:59
  Speaker 1: a popular So no. But I guess what you mean
• 18:01
  Speaker 1: is like, if you're out in space, you're not going
• 18:03
  Speaker 1: to see the northern lights and you're not going to
• 18:05
  Speaker 1: see a red sunset, but you might see this zotical light. Yeah, yeah,
• 18:09
  Speaker 1: you definitely should. All right, well, let's get into what
• 18:11
  Speaker 1: causes this interesting and mysterious effect, and let's talk about
• 18:16
  Speaker 1: what it could be and what we can learn from it.
• 18:19
  Speaker 1: But first let's take a quick break. All right, Daniel,
• 18:34
  Speaker 1: we are reading the signs of the universe, we are
• 18:38
  Speaker 1: aligning the planet, and we are looking at the zotical light,
• 18:41
  Speaker 1: which is an interesting and maybe mysterious effect that you
• 18:44
  Speaker 1: can see out in space coming off of the sun. Yeah.
• 18:47
  Speaker 1: It's really cool because it's something that you can see
• 18:50
  Speaker 1: with your naked eyes. Right, you don't need any equipment.
• 18:52
  Speaker 1: You just have to be sort of in the right time,
• 18:54
  Speaker 1: at the right place, and you can see this weird
• 18:56
  Speaker 1: space glow. And the cool thing is that it does
• 19:00
  Speaker 1: come from our atmosphere. As you say, it's a property
• 19:02
  Speaker 1: of the solar system itself, all right, So I assume
• 19:06
  Speaker 1: by now people and during the break when and Google
• 19:08
  Speaker 1: search zotical light and look the cool images of it.
• 19:11
  Speaker 1: And so now we know that it doesn't come from
• 19:13
  Speaker 1: our atmosphere, comes out from something in space. And so
• 19:16
  Speaker 1: step us through this. What is causing this mysterious light pattern. Well,
• 19:19
  Speaker 1: it's caused by the dirt and the dust that's in
• 19:22
  Speaker 1: the solar system. When you think of the solar system,
• 19:25
  Speaker 1: of course you imagine the Sun and the planets and
• 19:27
  Speaker 1: all their moons. But really the solar system is not
• 19:30
  Speaker 1: that crisp and clean and empty. It's actually filled with
• 19:34
  Speaker 1: all sorts of stuff. Of course, there's radiation from the
• 19:36
  Speaker 1: Sun shooting out particles, protons and electrons and gamma rays, etcetera, etcetera.
• 19:41
  Speaker 1: But also the solar system is not so neat and clean,
• 19:44
  Speaker 1: is huge dust clouds everywhere, and that dust is what
• 19:48
  Speaker 1: we are seeing. We are seeing the sun reflect off
• 19:51
  Speaker 1: of the dust that's in the plane of the solar system.
• 19:56
  Speaker 1: Wait wait, wait, wait, so our solar system is dirty.
• 19:59
  Speaker 1: Is that what it's dusty? Is it like dust left
• 20:02
  Speaker 1: over from when the Solar system formed, or is it
• 20:05
  Speaker 1: dust from like asteroids crashing? You know, where does this
• 20:09
  Speaker 1: does come from? Well, there's a long debate about the
• 20:11
  Speaker 1: origin of the dust, and it's not something we still
• 20:13
  Speaker 1: fully understand. Scientists are still trying to figure it out.
• 20:16
  Speaker 1: And one of the mysteries is that we're pretty sure
• 20:18
  Speaker 1: it can't be dust left over from the formation of
• 20:22
  Speaker 1: the Solar System because all that stuff got cleaned up
• 20:25
  Speaker 1: and slurped up into larger objects billions and billions of
• 20:28
  Speaker 1: years ago. All of our models of formations of solar
• 20:31
  Speaker 1: systems have this like collapse into a sun and a
• 20:34
  Speaker 1: protoplanetary disk, which then forms planets. But it's pretty efficient
• 20:38
  Speaker 1: and gathering up little bits of old stars and dust
• 20:41
  Speaker 1: and everything else that forms planets and meters and asteroids
• 20:44
  Speaker 1: and all that stuff. So when that's done, you really
• 20:46
  Speaker 1: shouldn't have much dust left over. You know, that dust
• 20:49
  Speaker 1: either should fall into the star or it should get
• 20:52
  Speaker 1: captured by other objects, right like like a planet X,
• 20:56
  Speaker 1: like a giant vacuum in the vacuum of space. Right
• 20:59
  Speaker 1: like if you have a giant rock flowing by, you're
• 21:01
  Speaker 1: going to be gravitationally attracted to it. Yeah. The whole
• 21:04
  Speaker 1: process of solar system formation is taking a big cloud
• 21:07
  Speaker 1: of gas and dust and collapsing it into bigger objects.
• 21:10
  Speaker 1: And once gravity gets that started, it's pretty effective. You
• 21:13
  Speaker 1: have a big mass, it's going to slurp stuff together.
• 21:16
  Speaker 1: And so we're pretty sure that the fact that we
• 21:18
  Speaker 1: still have dust means there needs to be a new source.
• 21:22
  Speaker 1: It needs to be replenished. It's like if you know,
• 21:24
  Speaker 1: when you built your house, it was clean, right, didn't
• 21:27
  Speaker 1: have any dust in it. Ten years later, if it
• 21:29
  Speaker 1: has dust in it, you know it's not from the
• 21:31
  Speaker 1: original builders, Right, there's some new source of dust making
• 21:34
  Speaker 1: your house dusty. Wow. Well, all right, we'll get into
• 21:37
  Speaker 1: the origin potential origin of this dust later. It's kind
• 21:40
  Speaker 1: of an interesting mystery. But I guess maybe explain to
• 21:43
  Speaker 1: us how this this dust forms this interesting light panttern. Yeah. Well,
• 21:47
  Speaker 1: this dust are like tiny little rocks, you know, they're
• 21:50
  Speaker 1: like one to three microns. These are really small, little,
• 21:54
  Speaker 1: tiny little particles, and they're flying out there in space,
• 21:56
  Speaker 1: and like most things in the solar system, they don't glow, right,
• 21:59
  Speaker 1: They're not on fire. They're not tiny little stars that
• 22:02
  Speaker 1: are shooting off photons. Instead, they're reflective. You know. These
• 22:06
  Speaker 1: things are like either frozen drops of hydrogen or they
• 22:09
  Speaker 1: have silka in them or something else, but they're reflective.
• 22:13
  Speaker 1: And so just like the Earth or the Moon or
• 22:15
  Speaker 1: the other planets, the Sun's light reflects off of this dust,
• 22:19
  Speaker 1: and so you can imagine what happens is that a
• 22:21
  Speaker 1: beam of light is shooting out of the Sun and
• 22:23
  Speaker 1: it hits this dust and it reflects just at the
• 22:25
  Speaker 1: right angle to come to Earth. Of course, it reflects
• 22:27
  Speaker 1: all sorts of crazy angles. So if you're above the
• 22:30
  Speaker 1: Solar System, you could also see this dust glowing, but
• 22:33
  Speaker 1: some of it will reflect right down on to Earth.
• 22:35
  Speaker 1: And that's what we see is the zodiacal light. Oh
• 22:38
  Speaker 1: I see. So it's sort of like sand almost like
• 22:41
  Speaker 1: there's just a cloud of sand out there, like covering
• 22:44
  Speaker 1: the dish of the Solar system. Right. It's not like
• 22:47
  Speaker 1: above the dish or below the dish. It's like it's
• 22:50
  Speaker 1: gathering kind of like a like a frisbee around the
• 22:52
  Speaker 1: Solar system. Yeah, exactly, it's in a disk like everything
• 22:55
  Speaker 1: else in the Solar System, and that's because it's rotating
• 22:58
  Speaker 1: with everything else in the Solar system. You know, you
• 23:00
  Speaker 1: might wonder, like, why does the Solar system have this
• 23:02
  Speaker 1: weird disc pattern, And that's because it's rotating. You know.
• 23:06
  Speaker 1: The reason that the Earth does not collapse into the
• 23:08
  Speaker 1: Sun is because it's moving really really fast around the Sun,
• 23:11
  Speaker 1: has this angular momentum that keeps it from collapsing into
• 23:15
  Speaker 1: the Sun. That only happens on the plane of this
• 23:18
  Speaker 1: rotation of the original mass of stuff. In the other direction,
• 23:21
  Speaker 1: like sort of above and below this disc, there's no rotation,
• 23:24
  Speaker 1: and so it's free to collapse. So that's why the
• 23:27
  Speaker 1: Solar system ends up as a disc and not like
• 23:29
  Speaker 1: a sphere, because it can collapse sort of in the
• 23:31
  Speaker 1: up and down direction along the Sun's axis, but it
• 23:35
  Speaker 1: can't collapse in the plane around the Sun. And so
• 23:39
  Speaker 1: like everything else, the disc is sort of trapped by
• 23:41
  Speaker 1: this rotation. But you know, like it slows down and
• 23:44
  Speaker 1: it falls into the Sun and like the Earth might
• 23:46
  Speaker 1: eventually m M I see. So it's sort of like
• 23:49
  Speaker 1: this giant disc cloud of sand and little tiny rocks,
• 23:53
  Speaker 1: and it's glowing, you're saying, because it's basically a reflecting
• 23:56
  Speaker 1: light from the Sun, Like the Sun shoots out light
• 23:59
  Speaker 1: and it hits this sand cloud, this dust cloud, and
• 24:01
  Speaker 1: then it makes it glow and we see it. And
• 24:04
  Speaker 1: that's kind of why we see it as a as
• 24:05
  Speaker 1: like a column in the sky, because there's no dust
• 24:08
  Speaker 1: above or below or you know, not in the plane
• 24:12
  Speaker 1: of the solar system. That's right. And you might be confused,
• 24:14
  Speaker 1: like why does dust glow? Dust doesn't seem like it glows.
• 24:17
  Speaker 1: And if you look at sand doesn't seem like a mirror, right,
• 24:20
  Speaker 1: But sand and dust are visible in sunlight. Right. The
• 24:23
  Speaker 1: reason you can see a beach, the reason it's not
• 24:25
  Speaker 1: like invisible or transparent, is because it is reflecting sunlight.
• 24:29
  Speaker 1: You know, the sun hits the sand and then comes
• 24:31
  Speaker 1: to your eye, and that's why you see it. If
• 24:34
  Speaker 1: sand didn't reflect light, if it just absorbed on the light,
• 24:36
  Speaker 1: it would be jet black, right, I guess it would
• 24:38
  Speaker 1: be like a black sand beach. So it's you know,
• 24:40
  Speaker 1: it doesn't sound like a property of dust or sand
• 24:43
  Speaker 1: to be reflective, but of course they do reflect some light,
• 24:46
  Speaker 1: and that's what you see. Or if you've ever seen
• 24:48
  Speaker 1: like moats of dust floating, you know, in the sunbeam,
• 24:51
  Speaker 1: then you're seeing them because they reflect light. And so
• 24:53
  Speaker 1: that's what's happening. And the reason we see it in
• 24:55
  Speaker 1: the sky is sort of fuzzy is because it's not
• 24:58
  Speaker 1: like a crisply defined object but sharp edges like a planet.
• 25:02
  Speaker 1: It's just this big cloud of dust that nobody's swept up, right,
• 25:05
  Speaker 1: I guess it's kind of like maybe like in a
• 25:06
  Speaker 1: foggy night, or in like a sort of like dewey
• 25:09
  Speaker 1: kind of human night. You see sort of a glow
• 25:12
  Speaker 1: around street lamps, right, That's kind of what it is.
• 25:14
  Speaker 1: It's the glow around street lamps is just the light
• 25:16
  Speaker 1: from the lamp kind of hitting the water or air
• 25:19
  Speaker 1: thus particles around it, and so you see this kind
• 25:21
  Speaker 1: of halo around street lamps, right exactly. And in principle,
• 25:25
  Speaker 1: you could see it during the day, you know, because
• 25:27
  Speaker 1: there's a huge clouds of it extending on either directions,
• 25:31
  Speaker 1: sort of along the path of the sun. But during
• 25:33
  Speaker 1: the day it's too bright, right, you just can't see it.
• 25:36
  Speaker 1: It's outshined by everything else. For the same reason you
• 25:38
  Speaker 1: can't see stars during the day. They're up there, they're
• 25:41
  Speaker 1: sending you photons, you're getting them, you just don't notice
• 25:43
  Speaker 1: it because you have this basically flashlight right in your
• 25:46
  Speaker 1: eyes of the sun. But the reason you can see
• 25:48
  Speaker 1: it just after the sun dips over the horizon is
• 25:52
  Speaker 1: that now the sky is dark enough and the angle
• 25:54
  Speaker 1: is just right for this part of the disc that's
• 25:56
  Speaker 1: sort of just over the horizon to get the Sun's
• 25:59
  Speaker 1: rays and and bounce right back to your eyes. I
• 26:02
  Speaker 1: see you were saying you're comparing it to the Milky
• 26:05
  Speaker 1: Way a little bit, because the Milky Way is also
• 26:07
  Speaker 1: sort of in a disc, and we're on that disc.
• 26:09
  Speaker 1: And so when you look at the night sky you
• 26:11
  Speaker 1: and you were able to see the Milky Way, you
• 26:12
  Speaker 1: see it as a streak across the sky. But that's
• 26:15
  Speaker 1: only I guess, because the Milky Way itself glows, right,
• 26:18
  Speaker 1: it's made out of stars, and so you see it
• 26:20
  Speaker 1: as a streak. But this one it needs to catch
• 26:22
  Speaker 1: the light of the Sun in a certain way. Yeah, exactly,
• 26:24
  Speaker 1: the Milky Way is visible because, as you say, these
• 26:26
  Speaker 1: are their own stars that have their own careers, and
• 26:28
  Speaker 1: they glow brightly on their own And it's a different line, right.
• 26:32
  Speaker 1: The plane of the Milky Way is not aligned with
• 26:34
  Speaker 1: the plane of the Solar system. So the Milky Way
• 26:37
  Speaker 1: in the zodiacal light don't have to line up, and
• 26:39
  Speaker 1: the milky Way is best seen deep, deep into the night.
• 26:41
  Speaker 1: When this when we're in the Earth's shadow and you
• 26:43
  Speaker 1: can't see the sun at all because it glows on
• 26:46
  Speaker 1: its own, but the zodiacal light, as you say, has
• 26:48
  Speaker 1: to reflect the light of the sun. And so if
• 26:50
  Speaker 1: the sun is on the other side of the Earth
• 26:52
  Speaker 1: it's like midnight or something, or deep in the morning,
• 26:55
  Speaker 1: then you're not gonna be able to see any of this.
• 26:57
  Speaker 1: Actually you can see a little bit sometimes, you can
• 27:01
  Speaker 1: see a little bit of it that reflects back from
• 27:03
  Speaker 1: the other direction. Yeah, because we are in the middle
• 27:06
  Speaker 1: of this, so you should see the outer edge of
• 27:08
  Speaker 1: the this too, right, Yeah, if the sun is right
• 27:10
  Speaker 1: behind us, like right in the middle of the night,
• 27:12
  Speaker 1: you can just hit some of this dust and it
• 27:14
  Speaker 1: can reflect back at just the right angle to our eyes.
• 27:18
  Speaker 1: So this this other thing in the middle of the
• 27:20
  Speaker 1: night called the gagan shine, which is a German word
• 27:23
  Speaker 1: for counter glow that are probably mispronounced. And it's at
• 27:26
  Speaker 1: the anti solar point, anti solar point being like the
• 27:30
  Speaker 1: opposite direction of the sun. So you draw a line
• 27:33
  Speaker 1: from the Sun to your head, and it's sort of
• 27:36
  Speaker 1: through that line in the other direction. It's like in
• 27:39
  Speaker 1: the shadow of the earth, right, Yeah, And this is
• 27:42
  Speaker 1: very hard to see, it's very faint, but in just
• 27:45
  Speaker 1: the right conditions you can see this sort of glowy
• 27:47
  Speaker 1: spot in the middle of the sky in the deep night.
• 27:51
  Speaker 1: And that's this counterglow. That's the light passing over the
• 27:55
  Speaker 1: earth from the sun and then hitting the dust and
• 27:57
  Speaker 1: coming back to your eyes. So sort like illuminating a
• 28:00
  Speaker 1: different part of this disc of dust that's out there, right,
• 28:04
  Speaker 1: Would you then see it as like a streak across
• 28:06
  Speaker 1: the sky? You you would, right now, I wouldn't just
• 28:08
  Speaker 1: be a spot. If you could illuminate the whole disk
• 28:10
  Speaker 1: and get back to your eye, you would see it
• 28:13
  Speaker 1: as a streak. But it's sort of like a fuzzy
• 28:15
  Speaker 1: spot because I think the shortest angles and the brightest
• 28:19
  Speaker 1: part of it is the parts that's directly illuminated, because
• 28:21
  Speaker 1: it's brightest when it directly back scatters, like when the
• 28:24
  Speaker 1: light hits the dust and you get like the full reflection. Interesting,
• 28:28
  Speaker 1: and so that in fact you can also see maybe
• 28:30
  Speaker 1: with your naked eye in in the middle of the night. Yeah,
• 28:32
  Speaker 1: And this is something I've never seen, but now I
• 28:34
  Speaker 1: want to. So next time. I'm happy to be up
• 28:37
  Speaker 1: at three am. I'm going to go outside and look
• 28:38
  Speaker 1: for the gig and shine. Yeah, but I guess you
• 28:43
  Speaker 1: live in a major city, or at least near a
• 28:46
  Speaker 1: major city, so that that might be pretty hard. Yeah,
• 28:48
  Speaker 1: I think it probably would be. Well, next time I
• 28:50
  Speaker 1: go camping and you're up its sleeping in your satellite mattress.
• 28:54
  Speaker 1: That's right, And it's sort of incredible that what you're
• 28:57
  Speaker 1: seeing are these tiny little things, like they are one
• 29:00
  Speaker 1: to three hundred microns. Like imagine if I told you, like, hey,
• 29:03
  Speaker 1: there's something three hundred microns in size floating out near Mars.
• 29:08
  Speaker 1: Go look about the night sky and see if you
• 29:10
  Speaker 1: can see it. You know that sounds ridiculous, right. You
• 29:13
  Speaker 1: couldn't even see like a boulder between here and Mars.
• 29:16
  Speaker 1: You couldn't, like if somebody put the Empire State Building
• 29:18
  Speaker 1: near Mars, you'd have no chance of seeing it. But
• 29:21
  Speaker 1: you get enough dust together and you get those photons,
• 29:23
  Speaker 1: they add up. It really can come to your eyes
• 29:25
  Speaker 1: and you really can't see it, right, They sort of
• 29:27
  Speaker 1: add up, not just because there's a lot, but because
• 29:29
  Speaker 1: there's a lot of space between here and Mars, right
• 29:32
  Speaker 1: and here in the sun and and so there, even
• 29:35
  Speaker 1: though it's mostly clear, all those little bits of dust
• 29:38
  Speaker 1: and sand add up. Yeah, and it's a lot of space.
• 29:41
  Speaker 1: And so even though we say like there's dust everywhere,
• 29:44
  Speaker 1: it's not actually that dense. Like the average distance between
• 29:47
  Speaker 1: these dust particles is like five miles, you know, like
• 29:51
  Speaker 1: eight kilometers, with the average distance between like little grains
• 29:55
  Speaker 1: of sand in space five miles. Yeah, exactly. If you
• 29:59
  Speaker 1: went on a tour, like you know, pub crawl from
• 30:02
  Speaker 1: dust mode to dust mode, it would take a while
• 30:04
  Speaker 1: to get from one to the other. I imagine if
• 30:06
  Speaker 1: they would be hard to find as well, like how
• 30:09
  Speaker 1: do you find one grain of sand in a five
• 30:11
  Speaker 1: miles fear of space? Yeah, and also they're moving pretty fast.
• 30:15
  Speaker 1: These things are moving at like tens of kilometers per second,
• 30:18
  Speaker 1: which is one reason why it's been a challenge to
• 30:20
  Speaker 1: study these things because it's hard to collect them. You know,
• 30:23
  Speaker 1: they're moving very very fast, and they're sort of sparse. Well,
• 30:26
  Speaker 1: as you said before, this kind of dust in the
• 30:29
  Speaker 1: Solar system wasn't always here, and it shouldn't be here
• 30:32
  Speaker 1: if the solar system was just left with its own devices, right,
• 30:35
  Speaker 1: Like the solar system in a way is sort of
• 30:37
  Speaker 1: like self cleaning. Like if there was any dust, it
• 30:40
  Speaker 1: would all either fall into a planet or into an
• 30:43
  Speaker 1: asteroid or into the Sun. So we should have a
• 30:45
  Speaker 1: pretty clean Solar system, but we don't. We have all
• 30:49
  Speaker 1: this dust. Yeah, gravity does a pretty good job of
• 30:51
  Speaker 1: tidying up. You know, you just leave things around and
• 30:53
  Speaker 1: they should just clump together and eventually form a black
• 30:56
  Speaker 1: hole of all of your garbage. Try that at home, folks.
• 30:58
  Speaker 1: That seems to happen in my house any because I'm
• 31:01
  Speaker 1: the only one who takes out the trash, and uh,
• 31:03
  Speaker 1: sometimes I put that off. But yeah, so it's kind
• 31:05
  Speaker 1: of a big mystery, then, where all this dust is
• 31:08
  Speaker 1: coming from, because the universe of the Solar System shouldn't
• 31:11
  Speaker 1: have any dust. Yeah, exactly. It's an area of research
• 31:15
  Speaker 1: right now, like people are doing studies and building models
• 31:18
  Speaker 1: and trying to understand where this comes from. And it's
• 31:20
  Speaker 1: something that people have been working on for, you know,
• 31:22
  Speaker 1: fifty sixty years. It was first discovered in the seventies
• 31:26
  Speaker 1: when people sent balloons up the upper atmosphere to gather
• 31:30
  Speaker 1: some of this cosmic dust that was falling to the Earth,
• 31:33
  Speaker 1: and that was pretty cool to discover. Wait, so we
• 31:35
  Speaker 1: we I guess we had seen this light effect for
• 31:37
  Speaker 1: a long time, probably a very long time, I imagine, right,
• 31:40
  Speaker 1: And so we didn't know what it was until the seventies.
• 31:43
  Speaker 1: It wasn' until the seventies people started sort of asking
• 31:46
  Speaker 1: what this was. Yeah, there were ideas that space dust
• 31:48
  Speaker 1: should exist or there should be out there, but people
• 31:51
  Speaker 1: weren't sure about how much dust there was, like is
• 31:53
  Speaker 1: it all interstellar dust? Is it really all cleared out
• 31:56
  Speaker 1: in the Solar System? And it wasn't until the seventies
• 31:59
  Speaker 1: that we started to sample the stuff and really measure
• 32:01
  Speaker 1: like how much cosmic dust is there? You know, they
• 32:03
  Speaker 1: sent up these balloon experiments and then later really high
• 32:06
  Speaker 1: flying airplanes to try to gather cosmic dust. And you
• 32:09
  Speaker 1: can tell the difference between dust that comes from the
• 32:12
  Speaker 1: Solar System and dust that comes from outside the Solar
• 32:15
  Speaker 1: System and things that are just like you know, dust
• 32:17
  Speaker 1: storms from Earth, because they all have a different makeup. Wait,
• 32:20
  Speaker 1: so I can put up a balloon that goes out
• 32:22
  Speaker 1: into near Earth orbit and I can catch some of
• 32:25
  Speaker 1: this space dust, Yeah, because tons of its falls to Earth. Right,
• 32:29
  Speaker 1: we say that there's just a grain every five miles
• 32:31
  Speaker 1: or so. But there's a lot of it, and so
• 32:33
  Speaker 1: some of it falls to Earth. Every day, It's like
• 32:35
  Speaker 1: tons of it is falling onto the Earth's surface. So
• 32:38
  Speaker 1: we can gather it up and we can study it. Wow,
• 32:40
  Speaker 1: like a little vacuant, Like put out a vacuum cleaner
• 32:43
  Speaker 1: out there in space. Well that's the process, right, Like
• 32:45
  Speaker 1: we're talking about how the Solar system cleans itself up.
• 32:47
  Speaker 1: That's how it happens. The Sun pulls some of it
• 32:49
  Speaker 1: into Earth pulls some of it, and everybody pitches in
• 32:52
  Speaker 1: and cleans this stuff up. We're flying through this cloud
• 32:54
  Speaker 1: of dust and the Earth is gathering it as we go.
• 32:57
  Speaker 1: That is definitely not how my household works. I wish
• 33:00
  Speaker 1: everyone pitched in. Tell your kids they just have to
• 33:03
  Speaker 1: run through the house and they'll just like gather all
• 33:05
  Speaker 1: the dirt on them. Yeah, they're it's part of their
• 33:07
  Speaker 1: star chores for their star allowance. All right, Well, let's
• 33:12
  Speaker 1: get into the origin of this dust, what it could
• 33:15
  Speaker 1: be made out of, and where it could be coming
• 33:17
  Speaker 1: from out there in space, and what we're doing to
• 33:20
  Speaker 1: study it. But first, let's take another quick break. All right,
• 33:36
  Speaker 1: So the Solar system apparently is pretty dusty. It's not
• 33:40
  Speaker 1: clean and Christine, as we thought it was, But it's
• 33:43
  Speaker 1: not the solar system's fault. Like, the solar system is
• 33:46
  Speaker 1: trying to keep a tidy pom here, but dust keeps
• 33:48
  Speaker 1: raining down on it and accumulating and forming this disk
• 33:52
  Speaker 1: around in the solar system that causes interesting light effects,
• 33:55
  Speaker 1: That's right. And people have been trying to figure out,
• 33:57
  Speaker 1: like where does this does come from? If the solar
• 34:00
  Speaker 1: system is constantly cleaning itself up, then what's the source
• 34:03
  Speaker 1: of dust? And for a long time people had a
• 34:05
  Speaker 1: couple of sort of obvious explanations. They were like, well,
• 34:08
  Speaker 1: what makes a mess in the solar system? You know,
• 34:10
  Speaker 1: what contributes to making new stuff or breaking stuff up?
• 34:15
  Speaker 1: And so one culporate our asteroids, asterids that like baying
• 34:19
  Speaker 1: into each other, because we have this big collection of
• 34:22
  Speaker 1: rocks out there between Mars and Jupiter and it's a
• 34:25
  Speaker 1: huge number and sometimes they hit each other and they
• 34:27
  Speaker 1: break up and that causes debris, and so people thought, well,
• 34:31
  Speaker 1: you know that must make a mess. You know, it's
• 34:32
  Speaker 1: like when your kids are cooking, you know, this spray
• 34:35
  Speaker 1: stuff everywhere. Wow? Yeah, yeah, because I guess you know,
• 34:38
  Speaker 1: the soliar sistem system is trying to clean itself. But
• 34:40
  Speaker 1: maybe whenever too asteroids crash, they just created a big
• 34:44
  Speaker 1: dust of basically rock little rocks, right, and so maybe
• 34:48
  Speaker 1: that's polluting the Solar system. That definitely is part of it.
• 34:51
  Speaker 1: And another culprit are comets. Remember, we have these objects
• 34:55
  Speaker 1: out there in the art cloud, these frozen balls, probably
• 34:58
  Speaker 1: trillions of them really are out, thousands and thousands of
• 35:02
  Speaker 1: au out there. It's really sort of incredible. Those of
• 35:04
  Speaker 1: you interested in that kind of stuff, check out our
• 35:06
  Speaker 1: whole podcast episode about the rag cloud. Really amazing stuff.
• 35:10
  Speaker 1: But what happens when comments come through the Solar system?
• 35:13
  Speaker 1: They zoom down towards the Sun and the Sun blows
• 35:16
  Speaker 1: a lot of stuff off of them. Right. Why do
• 35:18
  Speaker 1: comments have tails? Not because they literally have tails, but
• 35:21
  Speaker 1: because the Sun is boiling them away and stuff is
• 35:24
  Speaker 1: leaving the comet and so you can literally see it
• 35:27
  Speaker 1: leaving dust in a trail across the sky. That's what
• 35:30
  Speaker 1: the commets tail is. So that was another potential contribution to,
• 35:34
  Speaker 1: you know, the mysterious source of the space dust. If
• 35:37
  Speaker 1: it was comments would in those little grains that does
• 35:39
  Speaker 1: be made out of water. Then yeah, some of them are, right,
• 35:43
  Speaker 1: some of the space dust does come from water. And
• 35:44
  Speaker 1: as you say, the more we can study this space us,
• 35:47
  Speaker 1: the more we can figure out like who's contributing it,
• 35:50
  Speaker 1: because asteroids and comments are made out of very different things.
• 35:53
  Speaker 1: So those are two potential sources. Where where this mysterious dust.
• 35:57
  Speaker 1: But one other clue we know about it is that
• 35:59
  Speaker 1: it's sort of slowly falling into the solar system, right
• 36:03
  Speaker 1: like it's it doesn't seem to be kind of like
• 36:05
  Speaker 1: um made here. Maybe it's it seems to be sort
• 36:08
  Speaker 1: of moving and spiraling. Yeah, it's definitely spiraling in towards
• 36:12
  Speaker 1: the Sun. And if you look at a map for
• 36:14
  Speaker 1: like where it is, it's densest nearest the sun, right,
• 36:17
  Speaker 1: so the Sun pulls this stuff in. And you might wonder, like, well,
• 36:20
  Speaker 1: why doesn't the dust itself just orbit the way the
• 36:22
  Speaker 1: Earth does, like the Earth maybe very slowly falling in
• 36:25
  Speaker 1: towards the Sun, but it's or it's not decaying that rapidly.
• 36:28
  Speaker 1: And the reason is that these things do absorb a
• 36:30
  Speaker 1: good amount of light and then they radiate that light
• 36:32
  Speaker 1: off and that slows them down. So they're like absorbing
• 36:35
  Speaker 1: some of this energy and shooting it back off, so
• 36:37
  Speaker 1: that tends to slow them down, and so mostly it's
• 36:40
  Speaker 1: dense near the Sun and then it drops off extends
• 36:44
  Speaker 1: out just past Mars, and past that there's really not
• 36:47
  Speaker 1: very much space dust interesting, So it's not coming from
• 36:52
  Speaker 1: outside the Solar System. Maybe, is that kind of sort
• 36:54
  Speaker 1: of the what you would draw from that, since it's
• 36:57
  Speaker 1: only sort of in the inner Solar System, it's most
• 37:00
  Speaker 1: see in the inner Solar System. The truth is, we
• 37:01
  Speaker 1: don't really know what's going on in the outer Solar
• 37:03
  Speaker 1: System because we don't have great detectors. Like these things
• 37:06
  Speaker 1: are hard to measure, and as you get further out,
• 37:08
  Speaker 1: it's less and less and dense, which means it's harder
• 37:10
  Speaker 1: and harder to find them. So we actually have very
• 37:12
  Speaker 1: little data for the outer Solar System, but it seems
• 37:15
  Speaker 1: like it drops in density, it's ends around Mars, and
• 37:17
  Speaker 1: then there's basically nothing before Jupiter. Jupiter is like a
• 37:20
  Speaker 1: giant vacuum cleaner that like sucks up everything. But also
• 37:24
  Speaker 1: we do think that a little bit of it probably
• 37:26
  Speaker 1: does come from outside the Solar System. These interstellar star grains,
• 37:30
  Speaker 1: these leftover bits from the surfaces of stars that formed
• 37:34
  Speaker 1: and are floating out there. Some of those do appear
• 37:37
  Speaker 1: in our Solar System as space dust, but it's probably
• 37:40
  Speaker 1: not a huge contribution though. It's super fascinating actually because
• 37:44
  Speaker 1: you can tell what the stage of the star's life
• 37:47
  Speaker 1: when the grains were formed because of the materials fusing
• 37:50
  Speaker 1: inside of them. Yeah. Absolutely, And you can like see
• 37:54
  Speaker 1: grains that were made specifically during supernova, like these specific chemicals,
• 37:58
  Speaker 1: these specific elements that can only refused during supernova, and
• 38:02
  Speaker 1: these they make these specific grains which you can find
• 38:04
  Speaker 1: on Earth and use them to do studies. It's really
• 38:08
  Speaker 1: kind of amazing the sort of stellar archaeology you can
• 38:11
  Speaker 1: do by looking at these interstellar grains. But for space dust,
• 38:15
  Speaker 1: that's like a tiny fraction of what's out there. Interesting,
• 38:18
  Speaker 1: So then the origin of this dust must be within
• 38:20
  Speaker 1: our Solar system. Then it seems like it's within our
• 38:23
  Speaker 1: Solar system. And so you know, one culpritive course is
• 38:25
  Speaker 1: the asteroids, and the asteroids are out there sort of
• 38:28
  Speaker 1: past Mars, and so that doesn't really fit right because
• 38:31
  Speaker 1: the space dust is densest near the Sun and it
• 38:33
  Speaker 1: sort of dies out just around Mars. And if it
• 38:36
  Speaker 1: was being generated in the asteroid belt, which is between
• 38:39
  Speaker 1: Mars and Jupiter, you would expect a lot more of
• 38:42
  Speaker 1: it to be out there, but it gets cleaner and
• 38:44
  Speaker 1: cleaner as you get closer to the asteroid belt. Couldn't
• 38:47
  Speaker 1: it originate in the asteroid belt and then fall into
• 38:50
  Speaker 1: the inner Solar System and that's why you would see
• 38:53
  Speaker 1: you sort of see it, you know, not there and
• 38:55
  Speaker 1: more here, But that would have a different distribution. You
• 38:57
  Speaker 1: would definitely see more of it in the asteroid belt
• 39:00
  Speaker 1: before it falls in, right, But we see almost none
• 39:02
  Speaker 1: of it there. So they have some ways to study
• 39:04
  Speaker 1: these things. They have some detectors that they send up,
• 39:07
  Speaker 1: Like basically every probe that we send end to the
• 39:09
  Speaker 1: Solar System has a dust detector on it. But these
• 39:12
  Speaker 1: things are pretty small. Like the New Horizons probe had
• 39:16
  Speaker 1: a dust detector on it, but it was like an
• 39:18
  Speaker 1: eighth of a meter squared, which is pretty small. And
• 39:21
  Speaker 1: these things are pretty hard to catch because they're moving
• 39:23
  Speaker 1: so fast. So our studies of these things have been
• 39:26
  Speaker 1: pretty limited until we accidentally invented an awesome space dust detector.
• 39:31
  Speaker 1: We accidentally invented it. We accidentally invented it. Yeah, we
• 39:35
  Speaker 1: built this other probe called Juno to go discover Jupiter
• 39:38
  Speaker 1: and it has on it these incredibly huge solar panels.
• 39:42
  Speaker 1: These solar panels are like sixty square meters of solar
• 39:45
  Speaker 1: arrays to power this thing and on it, they also
• 39:48
  Speaker 1: have cameras, and these cameras are on the spacecraft, so
• 39:50
  Speaker 1: they can take pictures of the stars and you know,
• 39:53
  Speaker 1: orient themselves for navigation and basically tell the spacecraft where
• 39:56
  Speaker 1: it is. And they're constantly taking pictures. Well, one scientist, Denmark,
• 40:00
  Speaker 1: was like, you know what, we can do something else
• 40:02
  Speaker 1: with these. We could also try to catch pictures of
• 40:04
  Speaker 1: asteroids as we fly around the Solar System to see
• 40:07
  Speaker 1: if maybe there are any asteroids we missed. So he
• 40:10
  Speaker 1: programmed this camera not just to do that navigation, but
• 40:13
  Speaker 1: to let him know if it spotted any new objects,
• 40:15
  Speaker 1: any unknown objects in the Solar System, because he thought, hey,
• 40:19
  Speaker 1: it'd be cool to discover a couple of new asteroids
• 40:21
  Speaker 1: along the way. Interesting, like how is he or is
• 40:24
  Speaker 1: she expecting to find these asteroids like you know, like
• 40:27
  Speaker 1: a photo bomb almost like if you're looking out at
• 40:29
  Speaker 1: this base and it's like, hey, wait a minute, that
• 40:31
  Speaker 1: the little pinpoint they're glowing. You don't see it from Earth,
• 40:34
  Speaker 1: so it must be like an asteroid fly by, yea,
• 40:36
  Speaker 1: So it has these cameras any programmed to look for
• 40:38
  Speaker 1: any glint of light that corresponds to an object that's
• 40:41
  Speaker 1: not in the databasis, because that's how you see asteroids
• 40:44
  Speaker 1: right at the moment they happen to reflect light off
• 40:47
  Speaker 1: the Sun at just the right angle. So they have
• 40:49
  Speaker 1: a catalog of the known asteroids and they know where
• 40:52
  Speaker 1: the thing is pointing, so they can tell what they
• 40:54
  Speaker 1: should be able to see, you know, stars and visible asteroids,
• 40:57
  Speaker 1: and so any new source there is something interesting. And
• 41:00
  Speaker 1: so he programmed this thing. He thought I'd probably not
• 41:02
  Speaker 1: find anything, and then it started flying through the Solar
• 41:05
  Speaker 1: System and his camera went crazy. There's like crazy numbers
• 41:09
  Speaker 1: of images. He's like thousands and thousands of new things
• 41:13
  Speaker 1: that nobody had seen before. Wait what So they took
• 41:16
  Speaker 1: these pictures while it was flying to Jupiter, and it
• 41:18
  Speaker 1: turns out that there is a lot more than that
• 41:21
  Speaker 1: is not in the database. There's they saw a lot
• 41:23
  Speaker 1: of streaks in there that they couldn't identify as things
• 41:26
  Speaker 1: in the database. And at first I thought, oh, something's
• 41:28
  Speaker 1: wrong with the spacecraft. It's like leaking fuel or something.
• 41:31
  Speaker 1: We're like, you know, seeing the death of our spacecraft.
• 41:34
  Speaker 1: They couldn't believe that these things were like actually real
• 41:36
  Speaker 1: objects out there in the Solar system, and so they
• 41:39
  Speaker 1: were really wondering what these things were, like what is
• 41:41
  Speaker 1: going on here? And it turned out that what's happening
• 41:44
  Speaker 1: is that it's space dust. You're not seeing the space
• 41:47
  Speaker 1: dust itself because these particles are really small and very
• 41:50
  Speaker 1: fast moving. But the space dust was slamming into their
• 41:53
  Speaker 1: huge solar panels in the back and then like chipping
• 41:57
  Speaker 1: off a little piece that was then bouncing back, and
• 42:00
  Speaker 1: they were seeing that. So they're seeing like space dust
• 42:03
  Speaker 1: ricocheting little bits off of their space probe. Wait what
• 42:07
  Speaker 1: so wait, they weren't seeing the actual dust there was
• 42:10
  Speaker 1: seeing the dust bouncing off of the solar panel. What's
• 42:13
  Speaker 1: the difference. They're seeing shrapnel from the solar panel. So,
• 42:17
  Speaker 1: like you know, it's like you shoot a space dust
• 42:20
  Speaker 1: at this thing and it knocks off a tiny little
• 42:22
  Speaker 1: bit of the solar panel and then that's what you see.
• 42:25
  Speaker 1: Really whoa Well, first of all, that's kind of bad news,
• 42:28
  Speaker 1: isn't It means your solar panels is going to disintegrate
• 42:31
  Speaker 1: and eventually, But why is the shrapnel more visible than
• 42:34
  Speaker 1: the actual dust. Yeah, that's a good question. I think
• 42:36
  Speaker 1: the shrapnel itself is larger and probably more reflective. M M,
• 42:40
  Speaker 1: I see, like the actual dust you can't see, but
• 42:42
  Speaker 1: you can't see these little chips of solar panel. And
• 42:45
  Speaker 1: also the dust is moving really really fast and the
• 42:48
  Speaker 1: shrapnel is probably moving more slowly, so it's easier to
• 42:51
  Speaker 1: capture in a camera frame. WHOA, So we inadvertently created
• 42:55
  Speaker 1: a dust detector slash deteriorating solar panel. Yeah, so this
• 43:01
  Speaker 1: effectively became the largest space dust detector ever by a
• 43:05
  Speaker 1: factor of a thousand. Right, there are dedicated dust detectors
• 43:09
  Speaker 1: that have been flown out through the solar system, but
• 43:11
  Speaker 1: there are a thousand times smaller than the solar panels
• 43:14
  Speaker 1: of Juno, which in effect turned out to be pretty
• 43:16
  Speaker 1: sensitive to space dust. But only because we sort of
• 43:19
  Speaker 1: put cameras by accident looking at the solar panels or not.
• 43:22
  Speaker 1: Are they are they're looking at the panels? Are it's
• 43:24
  Speaker 1: sort of looking behind the panels. Well, they're sort of
• 43:26
  Speaker 1: looking in all directions, But some of the ones that
• 43:28
  Speaker 1: are pointing like behind the panels are the ones that
• 43:31
  Speaker 1: can capture these little shrapnels when it's space dust hits
• 43:34
  Speaker 1: the satellites. Solar panels the back side of them, which
• 43:37
  Speaker 1: fortunately the back side of them is the side that's
• 43:39
  Speaker 1: pointed away from the Sun, and so it's picking up
• 43:41
  Speaker 1: the space dust as it flies out of the Solar system,
• 43:43
  Speaker 1: and are also much more protected. Right the front side
• 43:46
  Speaker 1: of the side that's sensitive, that's pointed towards the Sun
• 43:49
  Speaker 1: is much more delicate. That's that's a little dangerous, Like
• 43:51
  Speaker 1: what if I was out there flying through space, wouldn't
• 43:53
  Speaker 1: I sort of be pelted by these things? And then
• 43:55
  Speaker 1: wouldn't they also trying into shrapnel. Yes, space is dangerous,
• 43:59
  Speaker 1: and if you're flying at very high speeds through space,
• 44:01
  Speaker 1: you need to worry about little particles and micro meteorites
• 44:04
  Speaker 1: and space dust. These grains carry a lot of kinetic
• 44:07
  Speaker 1: energy if you're moving at high speed. So yeah, absolutely
• 44:11
  Speaker 1: be careful next time you take that trip. Although I
• 44:12
  Speaker 1: guess if I can fly through space, it must be
• 44:15
  Speaker 1: pretty indestructible like Superman. But this is a great source
• 44:18
  Speaker 1: of data. They captured more than fifteen thousands of these collisions,
• 44:22
  Speaker 1: which lets them make a really detailed measurement of the
• 44:25
  Speaker 1: density of dust in the inner Solar System, much more
• 44:28
  Speaker 1: detail than anything we had before, and it told us
• 44:30
  Speaker 1: the story, which was a little bit of a surprise.
• 44:33
  Speaker 1: What have we learned? Well, we knew that the dust
• 44:35
  Speaker 1: was dropping in density, but now we have much more
• 44:37
  Speaker 1: detail that it ends like sort of just after Mars.
• 44:40
  Speaker 1: There's basically no dust after Mars, you know, until you
• 44:43
  Speaker 1: get to Jupiter. Past Jupiter, there's some dust, but Jupiter
• 44:45
  Speaker 1: like basically cleans up everything else. But there's no dust
• 44:48
  Speaker 1: basically between Mars and Jupiter, which sort of rules out
• 44:51
  Speaker 1: the asteroid belt as a large source of this dust.
• 44:55
  Speaker 1: Interesting because there is no dust close to the asteroid belt,
• 44:59
  Speaker 1: like you said, yeah, exactly, it sort of ends after Mars.
• 45:02
  Speaker 1: So then people thought, well, well what else could it be?
• 45:04
  Speaker 1: And it starts kind of around Mars, and so they thought,
• 45:08
  Speaker 1: Mars is kind of dusty. What if it's coming from Mars?
• 45:12
  Speaker 1: What mm hmm. But wouldn't Mars suck in dust just
• 45:16
  Speaker 1: like the Earth. Mars does suck in some dust, but
• 45:19
  Speaker 1: you know, it's much smaller than Earth and so it
• 45:21
  Speaker 1: doesn't have its powerful gravity, and what it does have
• 45:23
  Speaker 1: are powerful dust storms. So they don't yet have an
• 45:26
  Speaker 1: understanding for like how the dust is leaving Mars, but
• 45:30
  Speaker 1: it has a weaker atmosphere and weaker gravity and powerful
• 45:33
  Speaker 1: dust storms, and so they suspect that Mars might be
• 45:36
  Speaker 1: the source of this dust, that little grains of stuff
• 45:39
  Speaker 1: are leaving Mars and basically polluting our solar system. Whoa,
• 45:43
  Speaker 1: whoa wait wait wait to a storm on Mars is
• 45:47
  Speaker 1: powerful enough to like throw things out into space, like
• 45:51
  Speaker 1: to have it with enough velocity to have you know,
• 45:54
  Speaker 1: escape velocity, because that that doesn't happen on Earth, right,
• 45:56
  Speaker 1: Like the Earth doesn't speak stuff out into space, does it. Well,
• 45:59
  Speaker 1: the Earth sort of does spew stuff out into space.
• 46:01
  Speaker 1: Like our atmosphere, we're constantly losing it out into space
• 46:05
  Speaker 1: the upper edge of the atmosphere. The hottest molecules are
• 46:08
  Speaker 1: definitely flying out or we're losing our atmosphere gradually. And
• 46:11
  Speaker 1: also some of that are going to be dust particles
• 46:13
  Speaker 1: that are floating up there in the upper atmosphere. But
• 46:15
  Speaker 1: we have stronger gravity which makes it easier for us
• 46:18
  Speaker 1: to hang onto our atmosphere. But this is a part
• 46:20
  Speaker 1: of the theory that's sort of still speculative. They don't
• 46:22
  Speaker 1: have a very solid model for how the dust gets
• 46:26
  Speaker 1: off of Mars. They just have this sort of coincidential
• 46:28
  Speaker 1: evidence that it seems to start around Mars, you know,
• 46:31
  Speaker 1: and so it's sort of like your son was in
• 46:33
  Speaker 1: the kitchen and then it was a big mess, and
• 46:36
  Speaker 1: you're like, Mars is sous? Are you saying Mars is suns?
• 46:40
  Speaker 1: Exactly exactly? It is red interesting, but it sounds like
• 46:45
  Speaker 1: we have some candidates. So it could be comments. It
• 46:47
  Speaker 1: could still be asteroids, but maybe not so much. And
• 46:51
  Speaker 1: but now people are suspecting Mars. Yeah, and so it's
• 46:54
  Speaker 1: an activearya of research, and this is like a new element, knew,
• 46:57
  Speaker 1: something else to throw into the mix. Probably answer is
• 47:00
  Speaker 1: a little bit of all of them. There's going to
• 47:02
  Speaker 1: be some interstellar dust, some common tales, some asteroid debris,
• 47:06
  Speaker 1: and maybe some of Mars being a slab. And it
• 47:09
  Speaker 1: couldn't be anything else, could it. Could it be Earth
• 47:11
  Speaker 1: also being a little missy or maybe some of the
• 47:14
  Speaker 1: other planets. It could be, but you know, it sort
• 47:16
  Speaker 1: of starts out there near Mars, but it could be
• 47:18
  Speaker 1: that all the planets do contribute a little bit interesting
• 47:21
  Speaker 1: And so this is an active area of research, but
• 47:23
  Speaker 1: it's not a super popular area, right. Yeah, it's really
• 47:26
  Speaker 1: hard to study and there's not a lot of money
• 47:28
  Speaker 1: for space dust and these detectors that they put on.
• 47:30
  Speaker 1: These probes are sort of small, like the one that
• 47:33
  Speaker 1: was on New Horizons was built by students, sort of
• 47:36
  Speaker 1: low budget experiment, really awesome, but not like the hottest topic,
• 47:39
  Speaker 1: and sort of slow moving progress. So slow moving that
• 47:42
  Speaker 1: one famous scientist took a thirty seven year break from
• 47:46
  Speaker 1: his PhD thesis and was able to come back and
• 47:48
  Speaker 1: finish it and have it still be relevant. Nobody had
• 47:51
  Speaker 1: done anything in the meantime. What could this person have
• 47:55
  Speaker 1: possibly been doing for the thirty seven years. So this
• 47:57
  Speaker 1: is Brian May, who was an astrophysics p HD student
• 48:01
  Speaker 1: in V one when the little band he was in
• 48:04
  Speaker 1: called Queen started to really take off and he decided
• 48:08
  Speaker 1: maybe academia is not for me, and so he went
• 48:11
  Speaker 1: off and had a great career with Queen, doing rock
• 48:13
  Speaker 1: and roll, etcetera. And then in two thousand and seven
• 48:16
  Speaker 1: he thought, I never finished that PhD. I bet that
• 48:19
  Speaker 1: would be fun to wrap up, and so he went
• 48:21
  Speaker 1: back and they let him finish it and he defended
• 48:23
  Speaker 1: his PhD. Yeah it does he hold the record for
• 48:26
  Speaker 1: like the longest PhD ever or at least the most
• 48:29
  Speaker 1: you know, rock star thesis. I think he does hold
• 48:31
  Speaker 1: the record for the most number one hits of anyone
• 48:33
  Speaker 1: with a PhD. But his PhD was on the zodiacal
• 48:36
  Speaker 1: dust cloud, and so what he was measuring was the
• 48:39
  Speaker 1: velocity of these particles. Yeah, I guess maybe running a
• 48:42
  Speaker 1: proposal to study does doesn't make anyone too excited. In yeah,
• 48:48
  Speaker 1: it got him excited. I mean, remember that any time
• 48:50
  Speaker 1: we learned something in science, it's because somebody has dedicated
• 48:53
  Speaker 1: their life and their career to that topic. When you're
• 48:56
  Speaker 1: learning about, like, you know, the mating rituals of praying Manti,
• 48:59
  Speaker 1: that's because somebody has devoted their life to it. And
• 49:02
  Speaker 1: so everything we learned requires some expert in that area.
• 49:06
  Speaker 1: And you know, Brian May decided that zodiacal dust was
• 49:09
  Speaker 1: going to be his career. Then again, he also abandoned
• 49:12
  Speaker 1: it to become the electric guitarist for Queen. But he
• 49:15
  Speaker 1: came back right like he abandoned being a rock star
• 49:18
  Speaker 1: to go into sign So you know he came back.
• 49:22
  Speaker 1: What's important. Yeah, well he didn't exactly come back when
• 49:24
  Speaker 1: Queen was at its heyday or anything, but yeah, he
• 49:27
  Speaker 1: stayed number two on his list for a long time. Well,
• 49:29
  Speaker 1: I guess you know, again, it might you know the
• 49:32
  Speaker 1: origin of this dust, and even though it just does,
• 49:35
  Speaker 1: it might tell us a lot about sort of like
• 49:36
  Speaker 1: how the Solar system works, and maybe how storms and
• 49:39
  Speaker 1: Mars work, and also kind of about the origins of
• 49:42
  Speaker 1: the Solar system, right, and it just gives us sort
• 49:45
  Speaker 1: of a fuller picture of what's going on. We had
• 49:47
  Speaker 1: a sort of simplistic model for the Solar system of
• 49:50
  Speaker 1: mostly being the Sun and a few planets. Now we
• 49:52
  Speaker 1: know there's a lot more going on out there. There's
• 49:54
  Speaker 1: the or Cloud with these trillions of icy objects, and
• 49:57
  Speaker 1: there's space dust and space weather and space wind, and
• 50:00
  Speaker 1: it's really quite a vibrant and full system out There's
• 50:03
  Speaker 1: lots of crazy stuff going on. Yeah. Yeah, it's pretty
• 50:06
  Speaker 1: interesting universe Solar system. I think it might be a
• 50:09
  Speaker 1: Gemini the Solar system, which would explain everything. Man, do
• 50:13
  Speaker 1: the constellations have their own zodiac signs, like as the
• 50:16
  Speaker 1: Gemini constellation and aries or something. It sounds like another
• 50:21
  Speaker 1: long PhD thesism to delve into that will take thirty
• 50:24
  Speaker 1: seven years for sure. But yeah, So the next time
• 50:26
  Speaker 1: you look at the sunrise or sunset, keep an eye
• 50:29
  Speaker 1: out for this zodical light, right, you might see it
• 50:31
  Speaker 1: with your naked eye, and you might be looking at
• 50:33
  Speaker 1: a giant mystery that even physicists and rock stars are
• 50:37
  Speaker 1: pondering about. And if you do happen to spot it,
• 50:40
  Speaker 1: or if you see this gagenshine, you were looking at
• 50:43
  Speaker 1: tiny little grains of dust, far far out into space
• 50:47
  Speaker 1: beaming back their photons to you. Because in the universe,
• 50:50
  Speaker 1: I guess little things add up. That's right. We have crowdsourced,
• 50:52
  Speaker 1: we have dust sourced, a little bit of photons. Give
• 50:55
  Speaker 1: them a little bit of a chore to each one.
• 50:57
  Speaker 1: They'll get it done pretty soon. They're going to unionize,
• 51:00
  Speaker 1: all right. Well, we hope you enjoyed that. Thanks for
• 51:02
  Speaker 1: joining us, See you next time. Thanks for listening, and
• 51:12
  Speaker 1: remember that Daniel and Jorge explained. The Universe is a
• 51:15
  Speaker 1: production of I Heart Radio. For more podcast for my
• 51:18
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• 51:22
  Speaker 1: or wherever you listen to your favorite shows. H