29 August, 2007 Leave a comment
In case you missed the total lunar eclipse last night, here’s a composite as seen from the Carter Observatory here in Wellington (via stuff.co.nz)
Don’t be mislead by the images on the top row – the moon’s disc was never actually obscured as it moved into the earth’s shadow. In reality it looked more like the images on the bottom row with the bright full moon dimming from the bottom up. The top three obviously had a lower exposure to reduce the brightness of the full moon.
And in case you’re wondering why the moon goes red during a total eclipse here’s a quick explanation… Even though the moon moves into the earth’s shadow, some light is refracted (or bent) by the earth’s atmosphere and still reaches the moon. As the sunlight passes through the atmosphere the shorter blue wavelengths are scattered out by dust particles leaving more of the longer red wavelengths in the light that reaches the moon, hence the reddish tinge (the same process that leads to red sunrises and sunsets).