Geological Map of the Moon 2

[Stub Mandrel]

This image is a more subtle but perhaps more informative image showing the moon's geology.

 

I took twenty frames of the moon on 7 October 2017, using my Nikon Coolpix 520 on an ordinary photographic tripod. Rapidly closing cloud limited the number of usable frames, and I haven’t had an opportunity to collect any subs of a fuller moon since the challenge was posed. This means I have to make the best of what I have as there won’t be another full moon during the challenge.

I stacked the frames using PIPP and AS!2. Processing was in photoshop, but instead of going for detail I adjusted colour balance and saturation to maximise the distinction between different rock and terrain types, guided by a simplified geological map. This version uses a much less reduced colour palette, so the different areas are less boldly distinguished but the geology is mapped with much better fidelity.

Again, the effect is not perfect because at the edges of the disc and near the terminator the colours are less distinct, and some terrains are a mix of two or three distinct colours.

I used the USRA’s outstanding Geologic Map of the Nearside of the Moon as a reference to try and better understand what it shows.

www.lpi.usra.edu/resources/mapcatalog/usgs/I703/

Here are some interesting observations on what my image shows:

Mare Serenitatus

Note the purple-coloured mare material of the Eratosthenian System around the edges of the sea while the central brown area represents mare materials of the Imbrium system. This approach reveals differences that are barely visible in topographic images.

Mare Tranquillitatus

This sea is largely dominated by the Imbrium system, however with this processing it appears a very distinct cobalt-blue colour. The pale blue patches represent main-sequence craters of the Imbrium system, of younger, but similar, age to the mare.

Note also the pale blue ‘tongue’ of material that flowed south from Mare Tranquillatatus when it was formed.

Mare Nectaris

This smaller sea appears the same colour as Mare Serenitatus, suggesting it may be more close in its composition or origins to Mare Serenitatus than Mare Tranquilitatus?

Mare Imbrium

As would be expected most of Mare Imbrium is filled with mare deposits from the Imbrium system, but the blue and purple-mottled areas largely represent mare material of the Eratosthenian system. The crater Timocharis  stands out in blue and is classified as a main-sequence crater of the Copernican system, younger than all of the mares.

Plato

Plato is an impact crater noted for its dark, flat central plain, note how the lava that fills the basin of Plato appears a similar coulr but darker than the similar mare material of Mare Imbrium.

Mons Appeninus

This Pre-Imbrian system mountain range is marked as a pale yellow arc which continues up between Mare Imbrium and Mare Serenitatus as Montes Caucusus. To the west it is less apparent, but is just visible as pale blue-green areas north of Erastothenes and Copernicus.

Tycho

The massive crater Tycho is a pale-blue patch near the bottom of the disc. The chaotic jumble of colour, mostly pink and yellow,  around it is reflected in the complex patterns of the ‘official’ geological map. Two of Tycho’s rays show as obvious green/blue streaks radiating at ninety degrees to each other. Many other rays and patches of ejecta from the Tycho impact can be found by looking closely – they generally share the same pale blue colour as Tycho itself.

Copernicus

Copernicus is much less obvious than Tycho, it is distinguishable as a pink and red area within its surrounding ejecta field in a mix of yellow, orange and green.

 

Other Features

Many other craters and features can be found by ‘blinking’ between a standard monochrome version of the data and the ‘coloured map’. For example, the small, bright crater Hind, near the centre of the disc and some other bright, young, craters appear blue in areas otherwise yellow and orange, although many others do not. There is clearly some link between albedo and colour, but it is far from a direct correspondence.

 

Conclusion

This has been a fascinating exercise and although the image may appear a simple or random colouring in of lunar features, the distribution of colours does bear a real relationship to the known geology of the moon from more sophisticated studies. I hope to repeat this in future with a larger dataset of the full moon.

[EWHB]

This is really cool!  Thank you!

[Stu]

Very interesting Neil.

Just so I understand, this is produced purely by adjusting the colour and saturation of the original data, not by any artificial 'fill' colouring of each different rock type?

[Stub Mandrel]

2 hours ago, Stu said:

Very interesting Neil.

Just so I understand, this is produced purely by adjusting the colour and saturation of the original data, not by any artificial 'fill' colouring of each different rock type?

Just colour and saturation - and very careful colour balance (and more patience than I can usually find!)

[Stu]

9 minutes ago, Stub Mandrel said:

Just colour and saturation - and very careful colour balance (and more patience than I can usually find!)

Thanks Neil. Impressive.