Lumenna-Súnáris System (6): Talentar

I/5. Talentar

Class: Eutalentic
Orbit (period): 1.49 au (664.3 T-days)
Orbit (ecc.): 0.03
Radius: 2,137 miles
Mass: 9.4 x 10²³ kg
Density: 5.51 g/cm³
Surface gravity: 0.54 g

Axial tilt: 26.1°
Rotation period: 23.5 T-hours

Black-body temperature: 216 K
Surface temperature (avg.): 230 K

Atmosphere: Primarily CO₂, some nitrogen, trace components (pre-ecopoesis).
Atmospheric pressure (sfc.): 0.21 atm (pre-ecopoesis)
Hydrographic coverage: 0% (pre-ecopoesis)

Satellites: 3 moonlets.

So, here we are, next world of the system: Talentar. It’s eutalentic, which is the fancy IGS classification term for “Mars-like”: geologically quiescent, cold, and dry, with thin, mostly-CO₂ atmospheres. And it’s very much like that: it could be Mars’s twin.

Which naturally made it the immediate best prospect for a colony and then for ecopoesis, much like, say, Mars – which meant Project Copperfall, followed by Project Redblossom. This is why so many of the figures here are given as “pre-ecopoesis”.

Prominent features visible at this time include Talarí Mons, a large shield volcano near the equator that became the base for the orbital elevator, and the Ashen Planitia from which it rises; Rel!in Crater, whose distinctive shape made it the basis of the zero meridian; the large southern polar depression that eventually became the Meridional Sea; Kirinal Planum, the large plain north of said depression that became a large expanse of “Talentar prairie”; the Five Valles, five large canyons in a claw formation, none as individually large as the Vallis Marineris but which together are a hell of a lot of chasm; the future site of Quinjano Dome, the planetary capital where the chasms come together; Lorai Vallis, site of a famous military cock-up in the Grand Colonial Charlie Foxtrot; and so forth…

And now, the satellites. All figures given for these are pre-ecopoesis, because the ecopoesis involved moving them…

I/5/a. Móstal

Class: Aggregate
Orbit (period): 6,294 miles (2.91 T-hours)
Orbit (ecc.): 0.0
Radius: 6.33 miles
Mass: 1.4429 x 10¹⁶ kg
Density: 3.254 g/cm³
Surface gravity: 0.0009 g

Axial tilt: 0.01°
Rotation period: 3.56 T-hours

Black-body temperature: 216 K
Surface temperature (avg.): 209 K

Atmosphere: None.
Hydrographic coverage: 0%

As its planetary class indicates, Talentar’s innermost moon is… a rubble pile. And as its orbit indicates, one that is probably going to break up rather messily if untouched for the next few million years.

What that means in turn is that Móstal, for practical purposes, consists of a flag and some radio beacons and some fancy netting to keep it together when they had to move it to keep it out of the way of the orbital elevator…

I/5/b. Víërtal

Class: Silicaceous
Orbit (period): 12,740 miles (7.27 T-hours)
Orbit (ecc.): 0.0
Radius: 4.784 miles
Mass: 7.6325 x 10¹⁵ kg
Density: 4.08 g/cm³
Surface gravity: 0.0008 g

Axial tilt: 0.02°
Rotation period: 7.88 T-hours

Black-body temperature: 216 K
Surface temperature (avg.): 209 K

Atmosphere: None.
Hydrographic coverage: 0%

Víërtal, by contrast, is a bit more solid. It’s an actual silicaceous asteroid, look!

Its history has mostly been quiet: due to its solidity and its convenient altitude and habit of whipping around Talentar a good three times every day, it made a convenient base during the initial colonization. It still houses domes into much later eras, notably including the local space-traffic monitoring and defense systems, but it is, for the most part, a backwater.

It also had to be moved in order to build the orbital elevator.

I/5/c. Avétal

Class: Chondraceous
Orbit (period): 26,905 miles (22.30 T-hours)
Orbit (ecc.): 0.0
Radius: 3.87 miles
Mass: 1.9672 x 10¹⁵ kg
Density: 1.93 g/cm³
Surface gravity: 0.0003 g

Axial tilt: 0.4°
Rotation period: 29.3 T-hours

Black-body temperature: 216 K
Surface temperature (avg.): 185 K

Atmosphere: None.
Hydrographic coverage: 0%

And finally, Avétal, the outermost moon. Another relatively solid one, albeit less like a silicaceous asteroid in composition and more closely resembling a carbonaceous chondrite.

It’s been busy all through the lifespan of Talentar as an inhabited world, for various reasons: having lots of harvestable volatiles, and being relatively easy to get to in delta-v terms among them. But they, strictly speaking, aren’t the main thing.

What’s the main thing?

Look at the orbital period.

Now go back and look at the rotational period of the planet.

If you’re an orbital elevator consortium wondering where you’re going to find a nice, convenient countermass to move into position just above talentosynchronous orbit, those numbers should make you very happy indeed.

Or, rather, they did, and that’s why Avétal as a moon is wholly owned and operated by the Talentar Skyhook & Spaceport Consortium, ICC.

(Once we get to the modern era, of course.)