# What does a solar eclipse look like from the moon?

**URL:** <https://boards.straightdope.com/t/what-does-a-solar-eclipse-look-like-from-the-moon/230177>\
**Category:** Factual Questions\
**Created:** [February 20, 2004, 8:54am UTC](https://boards.straightdope.com/t/what-does-a-solar-eclipse-look-like-from-the-moon/230177 "2004-02-20T08:54:29Z")\
**Posts on this page:** 5\
**Page:** 1

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**Author:** ![kip70](https://avatars.discourse-cdn.com/v4/letter/k/5f9b8f/32.png) [@kip70](https://boards.straightdope.com/u/kip70)\
**Post date:** [February 20, 2004, 8:54am UTC](https://boards.straightdope.com/t/what-does-a-solar-eclipse-look-like-from-the-moon/230177/1 "2004-02-20T08:54:29Z")

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If you were on the moon during a solar eclipse, what would it look like? Would there also be a corona, or would the earth be so big that there is no corona and it’s much darker than when you experience an eclipse on earth? The earths shadow must be a lot bigger when it can darken the whole moon, while the moon can only darken a small band on earth.

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**Author:** ![scr4](https://avatars.discourse-cdn.com/v4/letter/s/59ef9b/32.png) [@scr4](https://boards.straightdope.com/u/scr4)\
**Post date:** [February 20, 2004, 9:02am UTC](https://boards.straightdope.com/t/what-does-a-solar-eclipse-look-like-from-the-moon/230177/2 "2004-02-20T09:02:47Z")

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On earth, “solar eclipse” means the moon is directly between the sun and the earth. If you were on the moon during such an event, you would see a small circular shadow move across the face of the earth.

But you are talking about the other event, the one _we_ (on earth) call a lunar eclipse, where the earth is between the sun and the moon. During such an event the moon does not become completely black. It looks dark red because it’s illuminated by light refracted by the earth’s atmosphere. So if you were on the moon at that time, the earth should look like a bright red arc or ring. I’d imagine the red glow is so bright that it washes out the view of the corona.

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**Author:** ![BwanaBob](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/bwanabob/32/2985_2.png) [@BwanaBob](https://boards.straightdope.com/u/BwanaBob)\
**Post date:** [February 20, 2004, 12:22pm UTC](https://boards.straightdope.com/t/what-does-a-solar-eclipse-look-like-from-the-moon/230177/3 "2004-02-20T12:22:06Z")

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The earth is roughly 4x the Moon’s size. From the moon during an eclipse of the sun by the Earth, the sun would be completely covered, but I’d imagine you’d see the Earth as a black disk surrounded by some brightness.

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**Author:** ![gluteus\_maximus](https://avatars.discourse-cdn.com/v4/letter/g/f17d59/32.png) [@gluteus\_maximus](https://boards.straightdope.com/u/gluteus_maximus)\
**Post date:** [February 20, 2004, 3:30pm UTC](https://boards.straightdope.com/t/what-does-a-solar-eclipse-look-like-from-the-moon/230177/4 "2004-02-20T15:30:41Z")

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When viewed from Earth, the phenomenon that occurs when the Moon passes between the Sun and Earth, blocking Earth’s view of the Sun, is called a solar eclipse.

When viewed from the Moon, the phenomenon that occurs when the Earth passes between the Sun and the Moon, blocking the Moon’s view of the Sun, is called a solar eclipse.

When viewed from the Earth, the phenomenon that occurs when the Earth passes between the Sun and the Moon, blocking Earth’s view of sunlight reflected from the Moon, is called a lunar eclipse.

When viewed from the Moon, the phenomenon that occurs when the Moon passes between the Sun and the Earth, blocking the Moon’s view of sunlight reflected from the Earth, could be called a terran eclipse.

> [@](#):
>
> _from  
> [here](http://www.hermit.org/Eclipse/why_lunar.html) (with helpful illustrations):_
> 
> The shadow cast by the Earth has two parts:
> 
> ```
> * In the penumbra, the light from the Sun is partly blocked by the Earth, but not completely. **An observer standing on the Moon within the Earth's penumbra would see a partial solar eclipse;** we see the Moon dimming due to the reduced light, although in practice this is hard to detect with the eye.
> * In the umbra, the light from the Sun is completely blocked by the Earth. **Our lunar observer would see a total solar eclipse;** we see the Moon darkened, but glowing a dull red from light scattered by the Earth's atmosphere. 
> 
> ```

(bolding mine)

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**Author:** ![Max\_Torque](https://avatars.discourse-cdn.com/v4/letter/m/e9bcb4/32.png) [@Max\_Torque](https://boards.straightdope.com/u/Max_Torque)\
**Post date:** [February 20, 2004, 3:52pm UTC](https://boards.straightdope.com/t/what-does-a-solar-eclipse-look-like-from-the-moon/230177/5 "2004-02-20T15:52:00Z")

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Well, what was above called a “terran eclipse” shouldn’t look like a total blackness on the Earth. A total solar eclipse (when viewed from Earth) can be viewed only from part of the Earth at a time. Large areas remain unaffected, or receive only a partial shadow. See the map [here](http://sunearth.gsfc.nasa.gov/eclipse/SEplot/SEplot2001/SE2006Mar29T.gif) for an illustration. So, I reckon that, from the moon, the terran eclipse should look like a circular shadow on the Earth, but with large parts of the Earth still receiving full sunlight. When centered, there would likely be a wide bright ring around the moon’s circular shadow.
