Stage 1

Io

Hadean-like fire — a crust that never sits still

The most volcanic silicate world known. Almost no craters. Sulfur still paints the ground. The first visible rocky face in the sequence.

What the cameras and papers show

The surface is younger than about a million years. Impact craters are effectively missing because lava and sulfur keep covering them.

Hundreds of volcanic centers. Loki Patera is a lava lake hundreds of kilometres across. Mountains on Io rise higher than Everest. The heat is supplied by tides from Jupiter and the neighboring moons.

Juno’s gravity work (Park et al. 2024) says there is not a shallow global magma ocean. Eruptions come from a mostly solid mantle feeding local chambers.

Sulfur and sulfur dioxide frost sit on the surface. On Earth most sulfur ended up in the core. That contrast is a stage note, not a proof of identity.

How this site reads it

Compared with Earth, this looks like the volcanic first chapter — a Hadean-like world. That comparison is standard.

The hypothesis is stronger: Io is the living first stage of the present cycle, not a finished moon that happened to look like that chapter.

Tides explain the heat. They do not, by themselves, explain why the surface chemistry still looks like a world that has not yet hidden its sulfur.

What would kill this stage

If Io’s fire and sulfur are fully explained as a finished moon heated by tides, with nothing left of a first crust, Stage 1 comes off the table.