Space-species

Just an idle thought: what might a space-species be like?

Not a quadruped or biped, that's for sure. No "ped" at all. Limbed maybe, but multi-armed rather than -footed, I think. But "arms" with suckers, so as to be capable of moving across surfaces and resisting mild accelerations.

A separate head wouldn't make sense either: there's no meaningful up-n-down in zero G. A brain suspended at the centre of a spheroidal body, with eyes and ears on motile stalks, seems more suitable to the environment. Said stalks (and limbs too) would have to be opposing, otherwise the creature would spin when moving them.

Talking of movement, getting suspended in mid-air will be common. A means of controlled motion, rather than waiting for electrostatic attraction or air currents to waft you to a surface, has obvious survival value. Thus I think our creature will be capable of quite literally "farting about" in space. And, if it wants to move more quickly, ballistic excretion is an obvious (and probably solid-but-sticky) method.

The ability to survive exposure to vacuum for a period is another obvious survival thing. An external skeleton with valve-like bony flaps that automatically seal the body cavity in the event of sudden vacuum would work, albeit any extended stalks and limbs might be lost. An ability to rapidly regrow these would probably evolve. That said, the ability to see and communicate in vacuum would be handy, so maybe the stalks will be vacuum resistant instead.

Radiation would be a survival issue too. A low density body, and super-efficient cellular repair mechanisms would cope (chickens (or was it cockroaches?) can survive 50 times the lethal human dose, unless my memory deceives me).

Farty spiky balls, then. If they invade, we'll probably die laughing...