Accurately mapping the Moon

Golbolco

Golbolco

I've been trying to make a map of the moon that's accurate in proportion to the WorldA map of Earth. I've read from multiple sources that the Moon is 27% of Earth's size, so I made this mockup by shrinking a map of Earth down by 27%.
ltlAT4w.png

The thing is, I'm no math whiz and I'm not sure just how accurate this is. Anyone want to lend some advice on this?
 

jetpack

You're using the right numbers. The circumference of the moon is 27% the circumference of Earth's. Same with the diameter and the radius.
The length of the map is the distance around the equator, which is the circumference. The height of the map is half the circumference.

So that means the length and width of your map should be 0.27 times the length and width of our earth map. I didn't count pixels, but yours looks right.

The area of the moon is 7% of Earth's, but to get distance right you should use the distance percentages, which you did.

One thing you may or may not want do differently is to extend the map to include the poles. We don't have Earth's poles on the map, because they're not very interesting, but the Lunar south pole has water, and Wikipedia tells me there is supposed to be a mission to the Lunar north pole next year. (https://en.wikipedia.org/wiki/Astrobotic_Technology#Moon_Missions)
 
Golbolco

Golbolco

Alright, so using all of this information, plus the most common map used for the moon on the website, I was able to come up with this:
NJ9FwQG.png

If I can find a decent reference for the Moon's poles, I'll definitely make maps for them.
 
zalezsky

zalezsky

Golbolco said:
Alright, so using all of this information, plus the most common map used for the moon on the website, I was able to come up with this:
NJ9FwQG.png

If I can find a decent reference for the Moon's poles, I'll definitely make maps for them.
Click to expand...

I believe that google earth has done something detailed on the moon. You could check there too
 

rvbomally

Great work! I was working on a project similar to this, but I never finished it. The size I got for the Moon is the same as yours, for the record.
 
Gryphon

Gryphon

jetpack said:
One thing you may or may not want do differently is to extend the map to include the poles. We don't have Earth's poles on the map, because they're not very interesting, but the Lunar south pole has water, and Wikipedia tells me there is supposed to be a mission to the Lunar north pole next year. (https://en.wikipedia.org/wiki/Astrobotic_Technology#Moon_Missions)
Click to expand...
The north and south poles are sort of already on the Worlda,; the Robinson projection just stretches the pole out so it's basically the entire extreme top or bottom line on the map. :)
 
Imperator Frank

Imperator Frank

Golbolco said:
As far as I know, it's the whole moon including the dark side; it's just stretched out like the worlda map for Earth.
Click to expand...

The dark areas (the mares) are pretty much all on the the hemisphere facing earth, the dark side is mostly cratered uplands. Googling "map of moon" shows that your map is indeed only the one hemisphere.
 
Golbolco

Golbolco

Imperator Frank said:
The dark areas (the mares) are pretty much all on the the hemisphere facing earth, the dark side is mostly cratered uplands. Googling "map of moon" shows that your map is indeed only the one hemisphere.
Click to expand...

Hmm, this is going to be tough to correct. I'll have to shrink the current surface to fit in the dark side.
 
oshron

oshron

one compromise i've seen for this in the past has been to just have the moon map perfectly circular since, frankly, what most people will probably want to map is the side that's facing Earth--its where all the spacecraft land. one option could be to have two circular maps showing the near and far hemispheres
 

empty

One thing I've always wondered about here was the validity of having that division of the surface? What is it about the darker vs the lighter areas that is different? Would this be an important and evident feature on the surface to a human or human civilization? If not, is there something else we should be mapping and not be trying to emulate land vs. sea? Because, from my ignorant view, they just look like maps trying to emulate the appearance of the moon.
 
Gryphon

Gryphon

empty said:
One thing I've always wondered about here was the validity of having that division of the surface? What is it about the darker vs the lighter areas that is different? Would this be an important and evident feature on the surface to a human or human civilization? If not, is there something else we should be mapping and not be trying to emulate land vs. sea? Because, from my ignorant view, they just look like maps trying to emulate the appearance of the moon.
Click to expand...
Well, first of all, just having a big ol' blank spot is really bad looking and doesn't give any indication of what you're looking at.

The dark regions by and large are equivalent to the maria, which besides literally meaning 'sea' and therefore being an incredibly obvious analogy so that we have a recognisable map to work with and understand what we're seeing in context, they're also regions that have a considerably different geo(luna?)logical/graphical profile- they're large, relatively flat regions largely consisting of cooled magma rather than the assorted debris of crust material that make up the rest of the moon (and thus bears a striking analogy to the difference between oceanic crust and continental crust on the Earth), and tend to have a considerably lower-than-mean altitude. In terraformed-moon maps (which I imagine would be a significant chunk of the moon maps this would end up being used for), they'd roughly correspond to regions that would be flooded.
 

empty

Gryphon said:
Well, first of all, just having a big ol' blank spot is really bad looking and doesn't give any indication of what you're looking at.

The dark regions by and large are equivalent to the maria, which besides literally meaning 'sea' and therefore being an incredibly obvious analogy so that we have a recognisable map to work with and understand what we're seeing in context, they're also regions that have a considerably different geo(luna?)logical/graphical profile- they're large, relatively flat regions largely consisting of cooled magma rather than the assorted debris of crust material that make up the rest of the moon (and thus bears a striking analogy to the difference between oceanic crust and continental crust on the Earth), and tend to have a considerably lower-than-mean altitude. In terraformed-moon maps (which I imagine would be a significant chunk of the moon maps this would end up being used for), they'd roughly correspond to regions that would be flooded.
Click to expand...

Thanks for the explanation. After posting I looked it up and realized that it's pretty justified. I didn't think mares were actually that distinct from the rest of the moon's surface in composition and elevation. However, the "land" seems pretty heterogeneous still. Maybe it'd be useful when making moon maps to have an "upper" elevation shade for the vast swaths of land on the far side that are 5 km above "sea level".
 
Golbolco

Golbolco

Using Ashtagon's link to NOAA's maps, and Imperator Frank's link to G.Projector, I have been able to create this:
9rxpo15.jpg

It's certainly a step in the right direction, but of course it'll need to be shrunken down to the proper proportions and recolored. I also need to figure out a way to make the pesky earth outline go away.
 
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Ashtagon

Bear in mind that the image you used for that rendition is a photographic image, not an altitude map. In effect, you've mapped out the lunar albedo, not its altitude.

The last of those links I gave is the one to use for altitude, although that one too needs to have the gumpf cleaned off it.
 
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