This page lists the physical details of Planetocopia's world-models. The chart shows only key factors affecting life; boldface flags unusual situations sculpting life on that world. Each world's home page has more details. 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 hr day	Interglacial. Many sentients; one ape has tech monopoly
TILT!
SEAPOLE	1 Earth mass	1	1 G	293°K 20°C 68°F	1 Atm	O2: (20%), avail O2 1	CO2 300 ppm	1	1		24 hr day	Sea level up 110 m; mild maritime climate
SHIVERIA	1 Earth mass	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 hr day	Ice; sea drops 140 m; sapient birds evolve in Mediterranean Abyss
TURNOVIA	1 Earth mass	1	1 G	288°K 15°C 59°F	1 atm	O2 20%, avail O2 1	CO2 250-300 ppm	1	1		24 hr day	green Sahara, dry China, Scandinavian icecap
JAREDIA	1 Earth mass	1	1 G	286°K 13°C 56°F)	1 atm	O2 20%, avail O2 1	CO2: 300 ppm	1	1		24 hr day	Tropical land belt, ice-free Antarctica
FUTURES
DUBIA	1 Earth mass	1	1 G	294°K 21°C 70°F	1 atm	O2 22% Avail O2 1.1	CO2: 700 ppm!	1	1		24 hr day	Greenhoused! Sea up 110 m; coasts flooded, poles fertile
MARS REBORN	0.11 Earth mass	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 hr day	terraformed; many sentient species
VENUS UNVEILED	0.8 Earth mass	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 Earth mass	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 hr day	6-8 sapients, cooperative anarchism
LYR	7 Earth masses	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 hr day	Scattered lands in vast world-sea, 19 sapients (mostly fliers)
OISIN	0.04 Earth mass	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 hr day	Europa plus light! Abundant sea life under thin ice
THARN	0.25 Earth mass	0.66 (8300 km)	0.59 G	trenches 27°C, plains 17°C, uplands 2°C	trenches .4 to .5 atm plains 0.24 atm uplands 0.1 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 hr day	13 sapients in Earthlike trenches and Martian uplands
PEGASIA	0.5 Earth mass	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 hr day	Contest! Invent the natives!
XANADU	0.06 Earth mass	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 hr day	Cold ecology, ethane not water: a wetter Titan
CAPSICA	0.45 Earth mass	0.75 (9600 km)	0.67 G	353°K 50°C 122°F	2.4 atm	O2 21%. Avail O2: 2.52	CO2: 600 ppm	0.5 (265 M km2)	0.1		30 hr day	Earthlike uplands, HOT lowlands
LIBRATIA	1.15 Earth masses	1.12 (14,350 km)	0.915 G	283°K, 10°C, 50°F dayside 22°C, 72°F	3.2 atm	O2 16% Avail O2: 2.5	CO2: 320 ppm	1.25 (625 M km2)	0.22		96 hrs rotation; day length infinite	Tidelocked! Steamy patch, Earthlike ring, icy nightside
KAKALEA	1.52 Earth masses	1.12 (14,2950 km)	1.22 G	287°K 14°C 58°F	0.6 atm	O2 16%. Avail O2: 0.48	CO2: 450 ppm	1.25 (640 M km2)	.5		18 hr day	Earthlike, but mostly desert, sea and ice
CAPRICES
INVERSIA	1 Earth mass	1	1 G	286°K 13°C 55°F	Basins 1.8 atm, uplands .65	O2 24% avail O2 2.2 in basins	CO2: 300 ppm	1	0.08		24 hr day	Our continents are Inversia's seas
SIPHONIA	1 Earth mass	1	1 G	289°K 16°C 62°F	Deeps 1.6 atm, Uplands .7	O2: 20%	CO2: 350 ppm	1	0.1?		24 hr day	steamy, rugged abysses, cold ex-continents
ABYSSIA	1 Earth mass	1	1 G	293°K 20°C 68°F	1 atm	O2: 22%; avail O2 1.1	CO2: 300 ppm	1	1		24 hr day	low island-continents in coral seas
SUMMARY
Extremes among the 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: 120°K to 323°K (-244 to 122°F) Ratio: 2.69	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, size, air pressure Gravity and temp narrower.

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.

Be especially forgiving of the 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). I know what temperature I want; I'm crude about rigging the inputs to get it.

"Average worldwide temperature" can be deceptive. Some worlds have wide temperature spreads that the average conceals (Libratia); some are sharply two-tier (Inversia, Serrana, Siphonia and Capsica) or even three-tier (Tharn).

One apparent inconsistency isn't. CO2 levels don't always correlate with the strength of the greenhouse effect. If it looks wrong, 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.

I have geographic doubts, too. As I've found better maps of Earth's sea floor and seen how rugged it is (and how most maps 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 and Abyssia try to show Earth's true undersea complexity.

• Lateria: is unlisted because it's undeveloped: a planet tilted 90 degrees like Uranus. If a world spinning on its side, with extreme seasons, developed life, how would it be different?

More essays on climatology and terraforming: More planetology, climatology and terraforming:

• A 3D portrait of Io I sculpted for fun. Not really Planetocopian, no what-if premise, just portraiture plus a bit of speculation. But oh those crazy cliffs and colors!
• A recently rediscovered 1990 dream prompting the Planetocopia series: Tilt the Globe to Maximize Biomass
• A Venerian prehistory for Earth?: What the Pteros Tell
• Would we notice a Dino Singularity?
• What killed the dinosaurs isn't as sure as you think--and ignorance can kill us: Volcanism, Impacts and Mass Extinctions
• A dream pointing out how to build domeless colonies inside certain dense planetoids: Witch at the Iron Core
• Shout in a Crowd, or, How to Survey Galactic Civilization, a dream claiming some dreamers wander the galaxy sampling the frequency of intelligent life! Curiously, it implied the same range I heard months later at a planetology lecture: on the order of a million civilizations and billions of biospheres.
• More dreams on terraforming, climatology and other planets. I find these dreams both entertaining and (surprisingly) more astute than many people's conscious thoughts on these topics.
  • terraforming
  • global warming and climatology
  • Dreams of Mars, Luna and other worlds
  • a dream of Io
  • 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