11 ms·

Total lunar eclipse to meet 'supermoon'

43 points by m1k3r420 11y ago

dalke 11y ago
Is there anyone besides me who deeply dislikes the term 'supermoon'? It has no meaning other than near perigee, it's not like the difference in the apparent moon size is all that noticeable, and we don't say that ISS is a 'superstation' or a satellite in a Molniya orbit is a 'supersatellite' when near perigee.
- xefer 11y ago
  I hate the term also. It just seems like a product of superlative-driven headline click bait that has infected everything.
- FlyingAvatar 11y ago
  I saw Neil deGrasse Tyson "on tour" on Thursday, and this was one of his rants in his presentation: * Lunar eclipses are very common. They happen at least every 2 years. Every decade or so, they happen 4 times in two years. * The term "supermoon" is a painful over exaggeration, since the visible difference between it and the average moon is tiny. So yeah, enjoy the eclipse, but in the end it's the media trying to make news. :)
  - cgriswald 11y ago
    To play devil's advocate: * Supermoon lunar eclipses are uncommon. * The visible difference can be up to ~14%, and its significantly brighter too. But viewing the moon on the horizon will get you a bigger apparent size difference, no supermoon needed.
    - jsprogrammer 11y ago
      Do objects really get a larger apparent size at the horizon? I guess there might be a small magnification effect from the additional atmosphere and angle?
      - ezequiel-garzon 11y ago
        Possible explanations have only appeared in recent years. It looks like by trying to make an adjustment your brain gives you a distorted image. Truly amazing. https://en.wikipedia.org/wiki/Moon_illusion https://en.wikipedia.org/wiki/Moon_illusion
        jsprogrammer 11y ago
        Ah, so as I thought. There is no difference in apparent size. >A simple way of demonstrating that the effect is an illusion is to hold a small object (say, 1/4 inch wide) at arm's length (25 inches) with one eye closed, positioning it next to the seemingly large Moon. When the Moon is higher in the sky, positioning the same object near the Moon reveals that there is no change in size.
      - cgriswald 11y ago
        Yes. Not just the moon, but constellations as well. Maybe other things. There's no consensus on why. Refraction is one idea. Another is its the way our brains process the information from our eyes.
        jsprogrammer 11y ago
        Brain processing shouldn't affect apparent size. Apparent size can be measured easily. I'd guess the difference in apparent size between something at zenith and on the horizon is less than a percent.
        cgriswald 11y ago
        Sorry, I meant how it appears to you, not it's apparent size.
        jsprogrammer 11y ago
        I've been getting the moon in perfect view from my kitchen window for the last several evenings. It gets great framing from the treelines on the local hills and the walls of nearby buildings. I think the framing helps you to focus on the moon (it's relatively bright compared to the rest of the scene) and appreciate the detail (some of which you can actually see with decent human vision). You are also seeing it right next to objects that you have more familiarity with their size, which helps you to appreciate the scale of the object.
    - dalke 11y ago
      I believe the definition of 'supermoon' is 'closer than 90% of the time", so yes, it happens for about 10% of all eclipses. Let's coin 'superdupermoon' for the 1% case. And ... so what? As http://science.nasa.gov/science-news/science-at-nasa/2011/16mar_supermoon/ http://science.nasa.gov/science-news/science-at-nasa/2011/16... points out: > Okay, the Moon is 14% bigger than usual, but can you really tell the difference? It's tricky. There are no rulers floating in the sky to measure lunar diameters. Hanging high overhead with no reference points to provide a sense of scale, one full Moon can seem much like any other. About once a year Jupiter is in opposition. Should we call that a "super Jupiter"?
      - rev_bird 11y ago
        Clearly that would be a Supiter
        deleted 11y ago
        [deleted]
      - cgriswald 11y ago
        > I believe the definition of 'supermoon' is 'closer than 90% of the time" Within 90% of perigee, yes. > it happens for about 10% of all eclipses. Hayley's comet is visible for 100% of its orbits. It's passing is still a rare event because it happens typically once in a lifetime. A supermoon lunar eclipse will happen maybe half a dozen times in yours. It's an uncommon event. > And ... so what? If you're not interested, you're not interested. I don't like the term supermoon either. But it's interesting to me that the difference is measurable. Photographing the full moon at perigee and apogee and measuring the difference is my kind of fun.
        dalke 11y ago
        In your position as devil's advocate, how does your parallel to Halley's comment provide any justification to your counter-argument? We don't have a special term for a comet when it's within 10% of perihelion. Again, remember that you were being a devil's advocate. My "so what?" comment was mean to highlight the weakness of your counter-argument. It's not actually significantly naked-eye brighter but requires instruments to measure. Now you've jumped to something outside of the role that you've assigned yourself, because you switched to talking about 'your kind of fun' and using instruments to help with your fun. That's a very different topic than what you started with. Saying "X is an uncommon event" does not, on its own, justify or explain anything. There are millions of rare events every day. Should we celebrate when Jupiter is at perihelion? That's only once every 11.86 years. What about when Mars is in aphelion? 67P/Churyumov-Gerasimenko was at perihelion on 13 August 2015 - did you celebrate?
  - alexkadis 11y ago
    I'm just happy that astronomy is making the news
    - dalke 11y ago
      Are you sure it's not astrology making the news? That is, upon research I found that the term 'supermoon' comes from astrology, and isn't really used in astronomy.
  - Mz 11y ago
    Maybe you mean total eclipses? Because lunar eclipses happen two to three times every single year, always paired with a solar eclipse (two weeks apart). Most of them are partial eclipses.
- furyofantares 11y ago
  Maybe not a useful term for science but what's wrong with a fun celebratory event? The general population isn't interested enough to tolerate news stories about every full moon but they aren't so uninterested as to want zero coverage. If people want to be reminded to go out and look up every once in a while and have a minor social event on the Internet where people are looking at and sharing photos and articles with friends and strangers from all over the world, supermoons and lunar eclipses happen at a frequency that's pretty good for that, and why not have a fun name as well?
  - gus_massa 11y ago
    I don't think it's good to mix science and lies, even to make something more interesting to the people. Science tries to distil the true, it's not easy, it's full of error, it's full of egos and scientific politics, ..., but if the objective is not the true it's not longer science. For example, yesterday I saw a news coverage that discussed the relation between the lunar eclipse, the "supermoon" and the zodiac signs. (Do you know the zodiac signs are changing this night? Or it was yesterday? Anyway I think there are a few zodiac calendars with small differences at the borders.) Even if the zodiac thing makes the new more interesting, it's bad to mix it with the real scientific facts.
    - furyofantares 11y ago
      I think I see two differences in perspective that may be leading to communication errors. First, I don't see lies OR the science here -- I don't see anyone trying to imply that this is scientifically meaningful, I just see people enjoying a group event of looking at the moon. I suppose I am not sure why it is on Hacker News, though. It's fun, and it is related to intellectual curiosities, but it is not an intellectual curiosity itself. And second, when you say "even to make something more interesting to the people", it makes me think we have a different perspective on the cause here. I'm not advocating pushing a supermoon agenda in the name of getting people interested. I'm observing that people are interested in this event and choosing not to shit on their parade. If they start telling me to make life decisions based on the supermoon or any other astrology, that is another matter. I do have a different opinion about the mercury retrograde events, for example -- those I see framed entirely in astrological terms by people who are not using the opportunity to look up or share pictures, who don't even understand why apparent retrograde motion occurs. I don't think that's the same thing.
- TaylorSwift 11y ago
  I like supermoon. It sounds tasty.
- sixbrx 11y ago
  It is a bit of an exaggerated term, it raises expectations to a point that it can't really meet. The "super moon" to me is from last quarter to new moon when it's out of the way and not flooding the sky with its unwanted brightness so I can see the deep sky :)
jschwartzi 11y ago
Does anyone have the full date for the UTC time table in the article? Without the UTC date that table is basically useless.
- z92 11y ago
  Wikipedia page has it... https://en.wikipedia.org/wiki/September_2015_lunar_eclipse https://en.wikipedia.org/wiki/September_2015_lunar_eclipse

43 points by m1k3r420 11y ago

dalke 11y ago

Is there anyone besides me who deeply dislikes the term 'supermoon'? It has no meaning other than near perigee, it's not like the difference in the apparent moon size is all that noticeable, and we don't say that ISS is a 'superstation' or a satellite in a Molniya orbit is a 'supersatellite' when near perigee.

xefer 11y ago
I hate the term also. It just seems like a product of superlative-driven headline click bait that has infected everything.
FlyingAvatar 11y ago
I saw Neil deGrasse Tyson "on tour" on Thursday, and this was one of his rants in his presentation: * Lunar eclipses are very common. They happen at least every 2 years. Every decade or so, they happen 4 times in two years. * The term "supermoon" is a painful over exaggeration, since the visible difference between it and the average moon is tiny. So yeah, enjoy the eclipse, but in the end it's the media trying to make news. :)
- cgriswald 11y ago
  To play devil's advocate: * Supermoon lunar eclipses are uncommon. * The visible difference can be up to ~14%, and its significantly brighter too. But viewing the moon on the horizon will get you a bigger apparent size difference, no supermoon needed.
  - jsprogrammer 11y ago
    Do objects really get a larger apparent size at the horizon? I guess there might be a small magnification effect from the additional atmosphere and angle?
    - ezequiel-garzon 11y ago
      Possible explanations have only appeared in recent years. It looks like by trying to make an adjustment your brain gives you a distorted image. Truly amazing. https://en.wikipedia.org/wiki/Moon_illusion https://en.wikipedia.org/wiki/Moon_illusion
      - jsprogrammer 11y ago
        Ah, so as I thought. There is no difference in apparent size. >A simple way of demonstrating that the effect is an illusion is to hold a small object (say, 1/4 inch wide) at arm's length (25 inches) with one eye closed, positioning it next to the seemingly large Moon. When the Moon is higher in the sky, positioning the same object near the Moon reveals that there is no change in size.
    - cgriswald 11y ago
      Yes. Not just the moon, but constellations as well. Maybe other things. There's no consensus on why. Refraction is one idea. Another is its the way our brains process the information from our eyes.
      - jsprogrammer 11y ago
        Brain processing shouldn't affect apparent size. Apparent size can be measured easily. I'd guess the difference in apparent size between something at zenith and on the horizon is less than a percent.
      - cgriswald 11y ago
        Sorry, I meant how it appears to you, not it's apparent size.
        jsprogrammer 11y ago
        I've been getting the moon in perfect view from my kitchen window for the last several evenings. It gets great framing from the treelines on the local hills and the walls of nearby buildings. I think the framing helps you to focus on the moon (it's relatively bright compared to the rest of the scene) and appreciate the detail (some of which you can actually see with decent human vision). You are also seeing it right next to objects that you have more familiarity with their size, which helps you to appreciate the scale of the object.
  - dalke 11y ago
    I believe the definition of 'supermoon' is 'closer than 90% of the time", so yes, it happens for about 10% of all eclipses. Let's coin 'superdupermoon' for the 1% case. And ... so what? As http://science.nasa.gov/science-news/science-at-nasa/2011/16mar_supermoon/ http://science.nasa.gov/science-news/science-at-nasa/2011/16... points out: > Okay, the Moon is 14% bigger than usual, but can you really tell the difference? It's tricky. There are no rulers floating in the sky to measure lunar diameters. Hanging high overhead with no reference points to provide a sense of scale, one full Moon can seem much like any other. About once a year Jupiter is in opposition. Should we call that a "super Jupiter"?
    - rev_bird 11y ago
      Clearly that would be a Supiter
      - deleted 11y ago
        [deleted]
    - cgriswald 11y ago
      > I believe the definition of 'supermoon' is 'closer than 90% of the time" Within 90% of perigee, yes. > it happens for about 10% of all eclipses. Hayley's comet is visible for 100% of its orbits. It's passing is still a rare event because it happens typically once in a lifetime. A supermoon lunar eclipse will happen maybe half a dozen times in yours. It's an uncommon event. > And ... so what? If you're not interested, you're not interested. I don't like the term supermoon either. But it's interesting to me that the difference is measurable. Photographing the full moon at perigee and apogee and measuring the difference is my kind of fun.
      - dalke 11y ago
        In your position as devil's advocate, how does your parallel to Halley's comment provide any justification to your counter-argument? We don't have a special term for a comet when it's within 10% of perihelion. Again, remember that you were being a devil's advocate. My "so what?" comment was mean to highlight the weakness of your counter-argument. It's not actually significantly naked-eye brighter but requires instruments to measure. Now you've jumped to something outside of the role that you've assigned yourself, because you switched to talking about 'your kind of fun' and using instruments to help with your fun. That's a very different topic than what you started with. Saying "X is an uncommon event" does not, on its own, justify or explain anything. There are millions of rare events every day. Should we celebrate when Jupiter is at perihelion? That's only once every 11.86 years. What about when Mars is in aphelion? 67P/Churyumov-Gerasimenko was at perihelion on 13 August 2015 - did you celebrate?
- alexkadis 11y ago
  I'm just happy that astronomy is making the news
  - dalke 11y ago
    Are you sure it's not astrology making the news? That is, upon research I found that the term 'supermoon' comes from astrology, and isn't really used in astronomy.
- Mz 11y ago
  Maybe you mean total eclipses? Because lunar eclipses happen two to three times every single year, always paired with a solar eclipse (two weeks apart). Most of them are partial eclipses.
furyofantares 11y ago
Maybe not a useful term for science but what's wrong with a fun celebratory event? The general population isn't interested enough to tolerate news stories about every full moon but they aren't so uninterested as to want zero coverage. If people want to be reminded to go out and look up every once in a while and have a minor social event on the Internet where people are looking at and sharing photos and articles with friends and strangers from all over the world, supermoons and lunar eclipses happen at a frequency that's pretty good for that, and why not have a fun name as well?
- gus_massa 11y ago
  I don't think it's good to mix science and lies, even to make something more interesting to the people. Science tries to distil the true, it's not easy, it's full of error, it's full of egos and scientific politics, ..., but if the objective is not the true it's not longer science. For example, yesterday I saw a news coverage that discussed the relation between the lunar eclipse, the "supermoon" and the zodiac signs. (Do you know the zodiac signs are changing this night? Or it was yesterday? Anyway I think there are a few zodiac calendars with small differences at the borders.) Even if the zodiac thing makes the new more interesting, it's bad to mix it with the real scientific facts.
  - furyofantares 11y ago
    I think I see two differences in perspective that may be leading to communication errors. First, I don't see lies OR the science here -- I don't see anyone trying to imply that this is scientifically meaningful, I just see people enjoying a group event of looking at the moon. I suppose I am not sure why it is on Hacker News, though. It's fun, and it is related to intellectual curiosities, but it is not an intellectual curiosity itself. And second, when you say "even to make something more interesting to the people", it makes me think we have a different perspective on the cause here. I'm not advocating pushing a supermoon agenda in the name of getting people interested. I'm observing that people are interested in this event and choosing not to shit on their parade. If they start telling me to make life decisions based on the supermoon or any other astrology, that is another matter. I do have a different opinion about the mercury retrograde events, for example -- those I see framed entirely in astrological terms by people who are not using the opportunity to look up or share pictures, who don't even understand why apparent retrograde motion occurs. I don't think that's the same thing.
TaylorSwift 11y ago
I like supermoon. It sounds tasty.
sixbrx 11y ago
It is a bit of an exaggerated term, it raises expectations to a point that it can't really meet. The "super moon" to me is from last quarter to new moon when it's out of the way and not flooding the sky with its unwanted brightness so I can see the deep sky :)

jschwartzi 11y ago

Does anyone have the full date for the UTC time table in the article? Without the UTC date that table is basically useless.

z92 11y ago
Wikipedia page has it... https://en.wikipedia.org/wiki/September_2015_lunar_eclipse https://en.wikipedia.org/wiki/September_2015_lunar_eclipse