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Pax Abyssi

Science // Lava worlds

Seas of molten rock, each grown from its own heat

A lava world is a rocky planet so close to its star that its day side melts. Every one in Pax Abyssi is procedural: one process reads the planet's heat, its crust and a seed of its own, and draws its sea, its shore, the rafts of crust riding on it and the cracks that glow.

01 // In flight

Lava worlds as you see them from the seat

In the game705 planets, all landable

Frames from the game, the HUD off. The sun is the star's own, at its true size and colour, and each sea is drawn from that planet's numbers. Select a frame to see it full size.

Close over a lava world's crust: brown terraced sheets of rock, broad glowing red cracks running across them and four round pools of molten rock glowing at the left, open full size
HYG 7903 II, a heavily crusted lava world: sheets of crust in terraces round the point beneath its star, lit by it, the cracks glowing red and the last pools hottest at their middles.
In-game capture, pre-alpha, HUD off
A white star with a granulated face and a broad glowing corona on the left, an orange lava world swirled with yellow seams on the right, open full size
HYG 92567 II beside its star. From 0.025 AU the K dwarf GJ 4087 spans 17 degrees of the sky.
In-game capture, pre-alpha, HUD off
A huge white star with a mottled face and a wide halo fills the left of the frame, a thin red-brown crescent of a lava world on the right, open full size
Altais III as a crescent beside its star. Altais is a real G9 giant more than ten times the Sun's width, and from 0.22 AU it spans 29 degrees of this planet's sky.
In-game capture, pre-alpha, HUD off
A golden-brown planet filling the right of the frame, its whole crust grained by a fine web of bright veins and crossed by broad glowing cracks, open full size
HYG 81221 I, a moderate crusted lava world that still turns: golden crust grained by a fine bright web, one of the two newest lava types.
In-game capture, pre-alpha, HUD off
A dark brown lava world broken into large plates by glowing orange veins, against a dim blue nebula, open full size
HYG 98105 II, a vein-network lava world, its dark plates split by glowing veins, against a blue nebula in the backdrop.
In-game capture, pre-alpha, HUD off
A gold-orange planet filling the right of the frame, its glowing sea scattered with dark rafts of crust cut into plates by bright cracks, open full size
Altais III by daylight: a gold sea of magma with rafts of crust riding on it, each raft cracked into plates.
In-game capture, pre-alpha, HUD off
An orange planet close up on the left of the frame, its surface a swirl of yellow-white seams over orange melt, open full size
HYG 92567 II close in, an ultra-hot magma world whose open sea is seamed with hotter currents. It still turns, so its heat runs round it by latitude.
In-game capture, pre-alpha, HUD off
A black planet filling the right of the frame with a large orange star showing from behind its left edge, open full size
A star half hidden behind the night side of its lava world. From 0.046 AU an orange K dwarf spans 11 degrees of the sky.
In-game capture, pre-alpha, HUD off
An orange lava world on the right of the frame, its glowing sea swirled with currents and scattered with dark rafts of crust cut by bright cracks, open full size
A hot lava world with a warm night side: rafts of crust drift on its sea, and the night side still glows past the terminator.
In-game capture, pre-alpha, HUD off
02 // One process

Where rock melts, the sea begins

Every point on a lava world takes its temperature from its star: hottest beneath it, cooling towards the terminator, and on a planet still turning, hottest along its equator. That temperature is set against the range over which basalt melts. Above it the rock is a sea; through the range lies the shore, where crust forms and breaks; below it the ground is solid, and only its cracks still glow.

Each planet then wears the process with its own numbers: its day-side and night-side heat, how much of its sea is crusted over and a seed taken from the body itself, so no two seas share a coastline. The sea is level ground, so you can set down on a raft at its shore, and a locked world's sea sits beneath its star to within a few degrees.

The process draws what the painted study of each type asks for. Long fractures in crossing families split the dark plates of the vein worlds. The heavily crusted worlds lay their crust in terraced sheets round the point beneath the star, lit by it, with a star of glowing cracks at the centre. Lakes open where three floes meet, veins carry a hotter core and pinch out as they run, and a rotating world's lava band lies on its own equator.

There are 705 lava planets around the catalogue stars, in 369 systems. They are as common as the Kepler survey found: about one Sun-like star in two hundred holds a small planet that circles it in less than a day.

In the gameevery type, every planet landableIn developmentthe shore at walking distance
03 // Every type

18 lava types, from gold-white seas to frozen plates

In the game18 types in the game

Sorted the way the heat sorts them: ultra-hot, hot and moderate worlds locked to their stars, the volatile-rich worlds under a veil, and the worlds that still turn.

In Pax Abyssi: every sphere is our lava field drawn at the type's typical heat, seen from near its star in the default look. Hover or focus a tile for its name.

  • In the game
  • In development
  • Planned

Ultra-hot lava worlds

2 types · 2 in the game

Locked to their stars with day sides above 2,500 K: seas of gold-white magma, open to the rim or carrying rafts of crust that crowd towards the shore.

  • Pristine magma ocean, lava world LWTL-UH-PR: A gold-white sea of open magma, swirled, crust only at the rim. 20 planets. In the game.LWTL-UH-PR
  • Magma ocean with rafts, lava world LWTL-UH-VN: Gold-white sea, rafts of crust packed towards the shore. 24 planets. In the game.LWTL-UH-VN

Hot lava worlds

3 types · 3 in the game

Day sides of 2,000 to 2,500 K and seas of orange magma, rafts of crust riding on them and streaks fanning from beneath the star.

  • Classic magma ocean, lava world LWTL-HT-CL: An orange swirled sea with dark floes and a torn shore. 22 planets. In the game.LWTL-HT-CL
  • Strong surface currents, lava world LWTL-HT-FL: A sea in a band, bright east-west filaments, raft slivers. 43 planets. In the game.LWTL-HT-FL
  • Warm night side, lava world LWTL-HT-GL: Streaks fanning from beneath the star; rock past the shore glows red. 40 planets. In the game.LWTL-HT-GL

Moderate lava worlds

6 types · 6 in the game

Below 2,000 K the sea reddens and the crust gains ground, from a red-orange sea in a band to frozen plates holding a few red lakes. The commonest lava worlds in the catalogue: the cool magma end alone holds 168 planets.

  • Hot magma end, lava world LWTL-MD-MH: A red-orange swirled sea in a band, a broad smeared shore. 72 planets. In the game.LWTL-MD-MH
  • Cool magma end, lava world LWTL-MD-MC: A viscous crimson band with dark east-west smears. 168 planets. In the game.LWTL-MD-MC
  • Mixed plates and lava, lava world LWTL-MD-MX: Big dark floes in broad glowing channels, lakes where three floes meet. 29 planets. In the game.LWTL-MD-MX
  • Dense vein network, lava world LWTL-MD-VN: Dark plates cut by long glowing fractures in crossing families. 62 planets. In the game.LWTL-MD-VN
  • Heavily crusted, lava world LWTL-MD-CR: Terraced sheets of crust round the hot point, a star of glowing cracks. 51 planets. In the game.LWTL-MD-CR
  • Nearly dormant, lava world LWTL-MD-FR: Frozen plates, pale ridges and a few red lakes. 35 planets. In the game.LWTL-MD-FR

Volatile-rich lava worlds

2 types · 2 in the game

Locked worlds that kept a thick envelope of volatiles over their magma, so the glow is seen through a veil.

  • Cool atmosphere, lava world LWTL-VR-CL: A grey-tan veil, the glow a dim red patch beneath the star. 2 planets. In the game.LWTL-VR-CL
  • Warm atmosphere, lava world LWTL-VR-WM: A pale veil over a broad orange glow. 8 planets. In the game.LWTL-VR-WM

Rotating lava worlds

5 types · 5 in the game

Lava worlds that still turn. They are heated by latitude instead of from one point, so their lava runs all the way round, on the planet's own equator. The ultra-hot magma worlds are the second commonest lava worlds in the catalogue.

  • Ultra-hot magma, lava world LWN-UM-SD: An open sea all the way round, its weather drawn as hot seams. 74 planets. In the game.LWN-UM-SD
  • Hot crusted, lava world LWN-HC-SD: A web of glowing veins from pole to pole. 24 planets. In the game.LWN-HC-SD
  • Moderate crusted, lava world LWN-MC-SD: Golden crust grained by a fine bright web. 21 planets. In the game.LWN-MC-SD
  • Volatile haze, lava world LWN-HV-SD: A dark veined surface under a purple haze. 8 planets. In the game.LWN-HV-SD
  • Silicate haze, lava world LWN-HH-SD: A swirled lava band under a golden haze. 2 planets. In the game.LWN-HH-SD
04 // Two looks

As painted, or at true brightness

By default a lava world glows the way our painted studies of each type show it. LAVA LOOK, on the SPACE page of the options, switches to the scientific look: the black body at its true brightness against the light of the star. Seen that way a lava world's day side is a dull brown, its sea only a shade warmer than the land, because molten rock at 2,000 K is faint beside the sunlight falling on it.

The science of both looks, the sixteen original types and how one process draws them all is in our feature Seas of molten rock. Barren and icy worlds, which use the same generator, have their own page.

In the wikiLava worldUltra-short-period planetVolcanic worldSuper-Earth
Seas of molten rock
More science

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