Why didn't the Moon go fully red for this eclipse?

In summary, during the January 2019 lunar eclipse, observers around the coordinates (+30, -90) noticed an asymmetrical bright crescent of white light along one side of the Moon despite it being well within the umbra. This was attributed to the blue band effect, caused by the ozone layer refracting certain frequencies of light. This effect was captured in photographs, despite the challenging conditions of a 35mph wind. The blue band was explained as being the outer part of the umbra, with a more central eclipse needed to see the full red color of the Blood Moon. Additionally, a meteor was seen striking the Moon during the eclipse, adding an unexpected surprise to the event.
  • #1
swampwiz
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(For reference, I am around coordinates ( +30 , -90 ), and this is the January 2019 lunar eclipse.)

I am typing this at supposedly mid-eclipse, and yet I see a thin crescent of white (ash?) along one side. It seems that the Moon should be well within the umbra at this point.
 
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  • #3
@russ_watters has photographed that effect:
russ_watters said:
This is going better than I had hoped. I'm fighting a crazy 35mph wind, but still taking photos up to 1 second exposure. Here's the latest first pass processed.

View attachment 237632

russ_watters said:
Yes, it was taken right about maximum.

I was surprised to see the asymmetry. So what causes it? Is it due to atmospheric refraction bending a bit of sunlight around Earth?

[Edit; hmm, well I guess the red is too...]
 
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  • #4
jedishrfu said:
In this link, there’s a paragraph on the blue band that some folks will see due to the ozone layer refracting certain frequencies of light and that might explain what you’re seeing.

https://www.timeanddate.com/eclipse/why-does-moon-look-red-lunar-eclipse.html
They also have an animation which shows just how off center the Moon is in the Umbra;
https://www.timeanddate.com/eclipse/lunar/2019-january-21

@swampwiz thanks for starting this thread; This effect surprised me and I asked about it in my thread, not noticing you already had.
 
  • #5
Perhaps the current lack of significant stratospheric volcanic stuff ??

FWIW, I'd rather have a 'pink' Blood Moon than a Pinatubo...
 
  • #6
So basically the blue band is the outer part of the umbra, and to get the full red, there must be a more central eclipse?
 
  • #7
swampwiz said:
So basically the blue band is the outer part of the umbra, and to get the full red, there must be a more central eclipse?
yes
 

1. Why didn't the Moon go fully red for this eclipse?

The Moon didn't go fully red for this eclipse because of the Earth's atmosphere. During a lunar eclipse, the Earth blocks direct sunlight from reaching the Moon. However, some sunlight still passes through the Earth's atmosphere and is refracted towards the Moon. The Earth's atmosphere acts like a filter, scattering out shorter wavelength blue and green light and allowing longer wavelength red light to pass through. This is why the Moon appears red during a lunar eclipse.

2. How come the Moon appeared more orange than red during the eclipse?

The color of the Moon during a lunar eclipse can vary depending on the amount of dust and clouds in the Earth's atmosphere. If there is a lot of dust or clouds, the Moon may appear more orange than red. This is because the dust and clouds can scatter more of the shorter wavelength blue and green light, making the Moon appear more orange.

3. Why was the Moon not completely dark during the eclipse?

The Moon was not completely dark during the eclipse because of a phenomenon called "Earthshine." This is when sunlight reflects off the Earth and onto the Moon, giving it a faint glow. During a lunar eclipse, the Earth's atmosphere filters out most of the blue and green light, leaving mostly red light to reflect off the Earth and onto the Moon. This is why the Moon appears to have a faint red glow during a lunar eclipse.

4. Can the Moon ever appear a different color during a lunar eclipse?

Yes, the Moon can appear different colors during a lunar eclipse depending on the conditions of the Earth's atmosphere. As mentioned before, if there is a lot of dust or clouds, the Moon may appear more orange. Additionally, if there is a volcanic eruption or a large amount of pollution in the Earth's atmosphere, the Moon may appear darker or even brownish in color during a lunar eclipse.

5. Why do some lunar eclipses appear to be darker than others?

The darkness of a lunar eclipse can vary depending on the alignment of the Earth, Moon, and Sun. If the Earth is closer to the Sun during a lunar eclipse, the Earth's shadow will be larger and the Moon will appear darker. Additionally, the amount of dust and clouds in the Earth's atmosphere can also affect the darkness of a lunar eclipse. If there is more dust or clouds, the Earth's shadow may appear darker and the Moon may appear darker as well.

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