Reply to post: Re: Ceres bright spots iluminate without sun light


Adam Foxton

Re: Ceres bright spots iluminate without sun light

Rather than just insulting you, how about a little educated guessing?

The bright spots are bright. Really, really bright. Ceres' albedo is below that of our Moon but not by much, and on the moon the reflected sunlight is incredibly bright- that's why there are no stars in photos from the moon, the brightness had to be lowered that far to stop the cameras being swamped that the pinpricks of light became invisible.

Now look at the photo. Its actual brightness would be like looking at the sun through a slight cloud- still retina-searingly bright. It's clearly had its brightness lowered (or more likely the sensitivity of the camera was lowered). That dull-grey looking surface is very bright indeed. The really reflective spots are even brighter as they're reflecting far more of the sunlight.

When the brightness is juuust right for looking at craters etc, the reflective areas are still substantially above the maximum brightness that the camera can record- hence the brilliant white appearance. And they're so much brighter that the camera finds them off-the-scale bright even when they're not in direct sunlight.

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