Hacker News Reader

Comment by aspirin | Hacker News Reader

Is this the real reflectance of the moon? Seems so dark.

Usually we see the moon at night surrounded by night sky, which probably skews our perception of the real color of the surface material.

View on HN

Yes, Earth's average albedo is around 0.3 while the Moon's is only around 0.12.

https://en.wikipedia.org/wiki/Albedo

The moon has approximately the same color as fresh asphalt, so it’s expected. It only looks bright on the night sky because everything else (including the stars) is just far darker.

Conversely, what I thought was pretty cool is seeing the reflection of the sun off the oceans, roughly in the middle of the earth 'disc'. You can see a fuzzy bright spot that stays in the middle of the disc as the earth spins.

According to TFA the earth is just so much brighter.

Yes, indeed. The eposure of the photo must have been set to make earth look as bright as we expect, and leaving the moon darker.

Yes. I remember reading somewhere (Wikipedia probably) the moon is only about as reflective as asphalt, believe it or not. Imagine how much brighter moonlight would be if it were painted brilliant white (e.g. titanium dioxide pigment). I'd love to see a simulation. Would it be bright enough so we could see enough scattering that the sky would appear blue, I wonder.

Probably because that's the Dark Side of the Moon?

https://en.wikipedia.org/wiki/The_Dark_Side_of_the_Moon

Is that a joke? The dark side of the moon is not more often dark than the visible side. It is just never visible from Earth.

I'd suggest following the link that was posted.

"There's no dark side of the moon, really. Matter o' fact, it's all dark."

Thank you thank you thank you. I couldn't stop chuckling for at least five minutes.

I waited 24+ hours to respond because I didn't want to call undue attention to your comment. I didn't want anyone to downvote you for violating HN's unwritten proscript about humor.

Reply on news.ycombinator.com