Possible recent lunar volcanism Options

[Bjorn Jonsson]

This is very interesting - and unexpected (at least to me):

http://lroc.sese.asu.edu/posts/818

Apparently there may be small features of volcanic origin on the Moon that are less than 100 million years old. The images are also very interesting - I would probably never have guessed that the image at the top was of lunar terrain.

[Phil Stooke]

First, let me assure you there are no blue minerals here. The blue is not a true representation of the nature of the surface.

In general on atmosphereless bodies, freshly exposed material is brighter and 'bluer' (reflecting slightly more light from the blue end of the visible spectrum) and old material exposed to the space environment for a long time is darker and a bit redder. If you were there, looking at it, it would mostly look neutral but you might see a bit more red or brown in the darker areas and less red in the brighter areas.

Here we have a photo taken on film 40 years ago. We don't really know how well the film reproduced the actual color, or how it has changed in storage. It has been scanned - but is this a scan from the original negative or from a later print or negative? The scanner might not give a perfect reproduction of the source. Most important of all, the color balance process deliberately shifts the spectrum, and this is probably the most important source of a false blue tint.

Ina has a bright floor which has been exposed relatively recently in lunar terms - its floor might be 100 million years old, the dark regolith surface around it is much older and is space weathered - made darker and redder. The bright stuff is really fairly neutral in tone. Color balancing makes it look blue, but it is not.

Phil