Planetocopia: Tech Corner

by Chris Wayan, 2006

This page lists the physical characteristics of all the model worlds presented in Planetocopia. The home page of each planet or moon has more details than can possibly fit on a single chart, so this page focuses on factors affecting life. In most columns Earth=1.

NAME	Mass	Diam.	Grav	Temp.	Air pressure	% O2 & avail. O2	CO2: ppm	Surface area	Water by vol	% Land & Sea, and total land area	Day length	Character
EARTH as a benchmark	1	12,750 km	1 G = 10 m/s, 5 m/s2	288 K 15 C 60 F	1 atm	O2: 20% Avail O2: 1	CO2 350 ppm	500 M km2, 196 M mi2	ca. 109 km3		24 hrs	Interglacial. Many sentients; one ape has tech monopoly
TILT!
SEAPOLE	1	1	1 G	293 K 20 C 68 F	1 Atm	O2: (20%)	CO2 300 ppm	1	1		24 hrs	Sea level up 110 m; mild maritime climate
SHIVERIA	1	1	1 G	283 K 10 C 50 F	Avg 1 atm but up to 2 in Medit. Abyss	20% O2, avail O2 2 in Abyss	CO2: 250 ppm	1	1		24 hrs	Ice; sea drops 140 m; sapient birds evolve in Mediterranean Abyss
TURNOVIA	1	1	1 G	288 K 15 C 59 F	1 atm	O2 20%	CO2 250-300 ppm	1	1		24 hrs	green Sahara, dry China, Scandinavian icecap
JAREDIA	1	1	1 G	286 K 13 C 56 F)	1 atm	O2 20%	CO2: 300 ppm	1	1		24 hrs	Tropical supercontinent, ice-free Antarctica
FUTURES
DUBIA	1	1	1 G	294 K 21 C 70 F	1 atm	O2 22% Avail O2 1.1	CO2: 700 ppm!	1	1		24 hrs	Greenhoused! Sea up 110 m; coasts flooded, poles fertile
MARS REBORN	0.11	0.53 (6800 km)	0.38 G	282 K 9 C 48 F	Avg: 0.5 Hellas: 1 Tharsis 0.2	O2 30%. Avail. O2: avg. 0.7 Hellas 1.5	CO2 3000 ppm	0.28 (140 M km2)	0.05? Ice imports probably unneeded		24.6 hrs	terraformed; many sentient species
VENUS UNVEILED	0.8	0.95 (12,100 km)	0.9 G	298 K 25 C 77 F	3.6!	7.5% O2 avail O2 1.4	CO2 70 ppm?	0.9 (450 M km2)	0.3, all imported ice		336 hrs (14 days)	terraformed, ring-shielded; dozens of sentient species
THE BIOSPHERE VARIATIONS
SERRANA	0.33	0.75 (9600 km)	0.65 G	292 K 19 C 66 F	0.67 atm	O2 21% Avail O2 0.7	CO2: 900 ppm	0.56 (280 M km2)	0.07		16 hrs	6-8 sapients, cooperative anarchism
LYR	7.0!	2.2 (29,600 km at equator)	tropics 1.23 G poles 1.4 G	294 K 21 C 70 F	6 atm	O2 12% Avail O2 3.5	CO2: 150 ppm	5 Earths! (109 km2)	13		12 hrs	Scattered lands in vast world-sea, 19 sapients (mostly fliers)
OISIN	0.04	0.39 (5000 km)	0.3 G	203 K -70 C -94 F (air)	.034 atm	50% O2 Avail O2 0.1	CO2: 1200 ppm	0.15 (77 M km2)	0.2! Wet, for a tiny moon		128 hours (5.3 days)	Europa plus light! Abundant sea life under thin ice
THARN	0.25	0.66 (8300 km)	0.59 G	trenches 27 C, plains 17 C, uplands 2 C	0.67 atm	21% O2 Avail O2: trenches .5 plains .25 uplands 0.1	CO2: 3000 ppm	0.43 (216 M km2)	0.002! Dry! 1/500 of Earth's		48 hrs	13 sapients in Earthlike trenches and Martian uplands
PEGASIA	0.5	0.9 (11,300 km)	0.63 G	293 K 20 C 68 F	1.6 atm	O2 22% Avail O2: 1.76	CO2: 200 ppm	0.82 (415 M km2)	0.25		48 hrs	Unknown; invent a species!
XANADU	0.06	0.48 (6120 km)	0.26 G	120 K -153 C -244 F	2 atm	O2 0.1%. Reducing atmosphere	CO2: 0 ppm	0.22 (115 M km2)	ethane not water 0.01		18 hrs	Cold ecology, ethane not water: a wetter Titan
CAPRICES
INVERSIA	1	1	1 G	286 K 13 C 55 F	sea basins 1.8 atm, uplands .65	O2 24% avail O2 2.2 in basins	CO2: 300 ppm	1	0.08		24 hrs	Our continents are Inversia's seas
SIPHONIA	1	1	1 G	289 K 16 C 62 F	Basins 1.6 atm, uplands .7	O2: 20%	CO2: 350 ppm	1	0.1?		24 hrs	steamy, rugged abysses, cold ex-continents
ABYSSIA	1	1	1 G	293 K 20 C 68 F	1 atm	O2: 22%; avail O2 1.1	CO2: 300 ppm	1	1		24 hrs	low island-continents in coral seas
SUMMARY
Extremes among the 16 worlds, then the ratio between high & low	Mass: 0.04 to 7.0 Ratio: 180	Diam.: 0.39 to 2.2 Ratio: 5.64	Gravity: 0.26 to 1.41 Ratio: 5.4	Temp: -153 C to 25 C (-244 to 77 F)	Air pressure 0.034 to 6.0 Ratio: 176!	Oxygen: 0 to 24% Avail O2: 0 to 3.5	CO2: 70 to 3000 ppm Ratio: 43	Area: 0.15 to 5 Ratio: 33.3	Water: 0.002 to 13 Ratio: 6500!	Land: 4.5-94% Ratio: 22 Land area: 0.2-2.25 earths Ratio 11.25	Day: 12 to 336 hrs Ratio: 28	Wide ranges of wet/dry, air pressure, mass. Gravity and temp narrower. No truly hot world!

A table like this is poetry to nerds like me. Well, more than poetry. Striptease! The illustrated web tours are like a floral-print dress; here are the naked numbers underneath. And I'm as shy about them as I am of my naked skin. Be gentle on me, O my Nerdish people! These figures are inevitably rough.

Particularly problematic are the many factors contributing to average temperature: insolation (solar output and mean distance), albedo (amount of sun absorbed: affected by the different reflectivity of clouds, bare rock, water, ice), and greenhouse effects (air pressure and content, especially methane, water vapor and CO2).

And "average worldwide temperature" can be deceptive. Some worlds have wide temperature spreads that the average conceals; a few are sharply two-tier (Inversia, Serrana, Siphonia) or even three-tier (Tharn). But the chart reveals one definite hole: I need to try a hot world. Blisteria?

One apparent inconsistency isn't. CO2 levels don't always correlate with the strength of the greenhouse effect. If it looks like an error, check the total air pressure! 3,000 ppm of nothing much is still nothing much. Another culprit is insolation (solar energy), not listed above; several high-CO2 worlds are fairly far from their suns, preventing a runaway greenhouse effect: less sunlight to trap.

Though the problems don't show on this chart, I have geographic doubts, too. As I've studied better maps of Earth's sea floor and learned how rugged it is (and how most atlases smooth it out) I've come to doubt my drier worlds have enough volcanoes on their basaltic plains. Worlds with extensive shallow seas, like Pegasia, should be richer in islands; those with wide dry plains, like Serrana and Tharn, should have more rain-catching, freestanding peaks and ranges. I over-relied on Venus's picture: many vents, but few high peaks. But Venus is so hot, the rock's more elastic and lava's slow to cool; so most volcanoes are broad and low. On my much cooler worlds, it ain't necessarily so. Rather than go back and alter the earlier worlds, Siphonia (under construction) will show Earth's true undersea complexity.

I'm contemplating more Biosphere Variations, but they're still just ideas:

• Vaporia will be a world averaging 60 degrees Celsius (140 F)--and that's just the average. Exobiologists focus on near-freezing worlds like Earth; many said complex life couldn't survive above 50 C (121 F), before undersea vent-life proved them wrong! So... how would life evolve in a steambath world?
• Lateria: a planet tilted 90 degrees like Uranus. If a world spinning on its side, with extreme seasons, developed life, how would it be different?

1. a Venerian prehistory for Earth?: What the Pteros Tell
2. a dream pointing out how to build domeless colonies inside certain dense planetoids: Witch at the Iron Core
3. A collection of dreams about terraforming, climatology and other planets. I include these links because I find these dreams entertaining and (surprisingly) more astute than many people's conscious thoughts on these topics.
   • terraforming
   • global warming and climatology
   • dreams of Mars
   • dreams of Luna
   • a dream of Io
   • dreams of other worlds in general
   • Dreams of time: futurology, the deep past, time travel, reverse time, and parallel worlds
   • ecology
   • evolution
   • dreams on uplift (the genetic engineering of intelligent species)
   • populations and eco-crashes