A compilation of facts and speculation for fanfiction writers and interested parties. Might be useful for fanfiction of Baze's, Chirrut's and Bodhi's childhood.
Includes thoughts on:
Size
Landscape
Climate
Population
This will be long, so further info below the cut.
Jedha is a moon orbiting the giant (gas?) planet NaJedha.
SIZE:
Wookieepedia says the diameter is 11 263 km. For comparison:
3476 km (Moon)
6792 km (Mars)
11263 km (Jedha)
12756 km (Earth)
Conclusion: Jedha is almost the size of Earth. Whoa. I didn't expect that.
LANDSCAPE:
Desert and mesas. Sandstone and Kyber.
The surface that is almost entirely desert and mountains, as this picture suggests. No oceans, only little water in the atmosphere.
I discovered there is a thing like "sandstone karst"/SiO2 karst where karst-like features appear in sandstone and quarzite. Examples include the Ennedi Plateau in Chad, the Purnululu National Park in Australia and Mount Roraima – the latter is part of a chain of so called tepui plateaus in South America which are exactly the kind of mesa we're looking for, the only difference being that on Jedha, there isn't a rain forest surrounding the plateaus, but desert.
Typical features of such landscapes are: penury of water on the surfaces, tower karst, sandstone grykes, caves that emerged through corrosion on tectonical joints, karst springs, ...
Meaning you can include young Chirrut and Baze exploring cave systems in your Jedha fanfic. :-D
For the geological/geographical history of Jedha: It once must have been much more humid. It might have had a rain forest like the one surrounding the tepui in Venezuela. When we look at the picture of Jedha from orbit I linked above we can see the remnants of drainage systems, only that where once was forest now is this reddish desert. The mesas and caves and general landscape became the way they are now through corrosion. Then through a long process of desertification Jedha became the dry world we see – erosion is a big deal and the wind plays an important role with that.
Next point: CLIMATE
The climate is described as "cold" because of a "permanent winter", an arid climate with instances of "powerful torrents of rainfall." Okay, it's cold, but not cold enough for snow. If there's precipitation, it's rain. Why is it cold, then? Wind chill is the answer. The faster the wind, the colder it appears to us.
No snow, but a cold climate – I say the temperatures range from 0 to 10°C. Conveniently, the wind chill is defined from 10°C downwards, so let's stick with that. Now, how much wind is there on Jedha? Remember, there are only rocks and desert. No forest to alleviate it.
A gentle breeze (wind blows at 12-19 km/h, "Leaves and small twigs constantly moving, light flags extended." although there aren't any trees on Jedha, but you get the point) will feel like around -4.4°C min to 7.9°C max. I think that's the minimum of how much wind there is on Jedha at any point.
A fresh breeze (wind blows at 29-38 km/h, "Branches of a moderate size move. Small trees in leaf begin to sway.") will feel like around -6.5°C min to 6.6°C max. I estimate that this happens most of the time.
A high wind/moderate gale (wind blows at 50-61 km/h, "Whole trees in motion. Effort needed to walk against the wind.") will feel like around -8.8°C min to 5.1°C max. This is when things get rough and I don't think it happens often, but it does.
On the lee side of mountains/mesas it will feel warmer, but in general we can imagine a quite harsh climate: Always the wind, and then there's sand everywhere! People will want to keep their doors and windows shut, especially outside the city.
Next: PEOPLE
"Being an antiquated destination, Jedha was surrounded by uncharted systems, making it a reliable replenishment port for travelers." (wookieepedia, again) Also, it is home to NiJedha, the Holy City, and thus a place of pilgrimage with a rich history and architecture. It is located somewhere in the Mid Rim, probably far off known hyperspace routes (because the surrounding systems are uncharted).
There are 11.3 million people on Jedha. I imagine NiJedha is the biggest city. But how many people lived there?
There's this picture of a star destroyer looming over the city.
My rough estimation is that NiJedha's "length/diameter" is about 4/5 of the Star Destroyer's length. Since mesas are roughly ellipsoid, I'd say the "width" is about 2/3 of the length.
A Star Destroyer's lengths is 1600m. The measurements for NiJedha thus are: 1280m and 850m diameter which is an area of (only) 854 513 m² or 0.854513 km2.
How many people can live there?
I tried to compare it with the Old City of Jerusalem (the part of Jerusalem surrounded by the city's walls), which is ca. 0.9 km². Unfortunately, I couldn't find any reliable information on how many people lived there in pre-modern times. In 2007, it was a number of 36 965 living in this area.
Another example: Constantinople. The Walls of Constantine surround an area of ~ 6 km². In 361 AD, around 300 000 people lived there, that's 50 000/km².
I think that's a number we can use, so there are ca. 50 000 people living in a densely populated NiJedha.
11,3 million people on Jedha, only 50 000 of them in NiJedha.
But since that moon is as big as our Earth, the population density will be minimal. And: Although I imagine that comparatively many people lived in the region around NiJedha, more or less the whole planet will have settlements. And that again means that even after the destruction of the Holy City, not everything is lost. There will still be people living there, especially on the opposite side of the planet. (Although I can't assess the tectonical impact the Death Star beam has, or other long term consequences.)
Now I don't know if anyone beside me is interested in those informations, but I thought I'd share it. I am by no means a specialist on any of those topics, so if I’m wrong in some points, feel free to correct me.
If anyone wants to have more worldbuilding/background for their young spiritassassin fanfic, here you go. Also, feel free to add any additional thoughts!
In darkness, cold.
In light, cold.
The old sun brings no heat.
But there is heat in breath and life.
In life, there is the Force.
In the Force, there is life.
And the Force is eternal.
The Art of Rogue One | Jedha Alley Exterior versions 7G and 7I, Will Htay
We used Paris during World War II as inspiration, because of the occupation and how that parallels where we find Jedha in our story. It’s an ancient city that has quite a bloody history. It’s battle-scarred, and it’s been overrun by the Empire. Various battles went on here. (Al Bullock, supervising art director)