Slashdot Mirror


First Solar Eclipse Recorded From Moon

dazza101 writes "For the first time ever, we have witnessed a solar eclipse from the moon. On 10 February 2009 Japan's Kaguya lunar orbiter captured the sight of the Earth eclipsing the sun. The spacecraft also recorded this video showing the Earth surrounded by a glowing ring and briefly forming the classic diamond ring that often occurs during a solar eclipse, as seen from down here on Earth."

5 of 123 comments (clear)

  1. even better by jcgam69 · · Score: 5, Informative

    It's even better than a solar eclipse as seen from earth because the earth's atmosphere diffracts light from the sun, causing a ring of light to appear around the planet. Very cool.

    1. Re:even better by Bemopolis · · Score: 4, Informative

      That's not diffraction. The irregular surface of the moon partially blocks the sunlight during a solar eclipse, producing an effect called Bailey's beads. The drama of this effect is helped considerably by the rough equivalence of the sun and moon's angular size as seen from Earth.
      By comparison, on the moon the Earth is approximately three times the angular size of the Sun, so the illumination of the rim only occurs because of atmospheric diffraction. This diffraction of sunlight is also responsible for the reddish light one sees during a lunar eclipse.

      --
      "I guess the moral of the story is, don't paint your airship with rocket fuel." -- Addison Bain
  2. Terran Eclipse? by clintp · · Score: 4, Informative

    During a total solar eclipse (from the Earth's perspective), the ring of light around the moon is from the sun's photosphere showing around the edges of the moon.

    The ring around the earth in the solar eclipse (from the Moon's perspective) is from the light refracting from the atmosphere. I'd think the Earth's relative size would be far too large for an effect like Baily's Beads to be seen from the moon.

    Or am I missing something?

    --
    Get off my lawn.
    1. Re:Terran Eclipse? by mbone · · Score: 4, Informative

      You are correct. The Moon's angular size is close enough to the Sun's that some eclipses are annular (the Moon is too far away to cover the Sun). Even during a total eclipse, you can see the bright inner corona (not the photosphere - that's what makes it total).

      For lunar eclipses, the Earth will generally completely cover the Sun, inner corona and all. However, refraction through the Earth's atmosphere lights up the Lunar landscape, (i.e., the light of every Sun rise and Sun set going on everywhere on Earth). This light - the depth of the eclipse - has been used to infer global atmospheric conditions over historical time.

  3. Re:POV changes, name doesn't. by Intron · · Score: 4, Informative

    This is a solar eclipse because the Sun is being obscured. In a lunar eclipse the Moon is being obscured. If you're on the moon there are no lunar eclipses.

    If things always have the same name regardless of where they are viewed, why can't I get to my home coputer by typing "localhost"?

    --
    Intron: the portion of DNA which expresses nothing useful.