Paris ? Saturn’s largest moon apparently is lashed regularly by rain made of liquid methane, forming pools, cutting riverbeds and eroding rocks in much the same way that forces have shaped the Earth, scientists said Friday.

The European Space Agency’s probe that landed on Titan’s frozen surface a week ago put Europe’s stamp on the distant reaches of the solar system with its discoveries of a mysterious, methane-rich globe.

“We’ve got a flammable world, and it’s quite extraordinary,” said Toby Owen, a scientist from Honolulu’s Institute for Astronomy who was charged with studying the moon’s atmosphere.

Black-and-white photos from the Huygens probe show a rugged terrain of ridges, peaks, dark vein-like channels and apparently dry lake beds on the moon 744 million miles away.

On Earth, methane is a flammable gas. On Titan, it is a liquid because of the intense pressure and cold — 274 degrees below zero.

“There is liquid that is flowing on the surface of Titan. It is not water — it is much too cold — it’s liquid methane, and this methane really plays the same big role on Titan as water does on Earth,” said mission manager Jean-Pierre Lebreton. “There are truly remarkable processes at work on Titan’s surface and in the atmosphere of Titan which are very, very similar to those occurring on Earth.”

Channels on the surface are evidence of methane rain. There are also what appear to be river systems and deltas, frozen protrusions riddled by channels, apparent dried-out pools where liquid has perhaps drained away, and stones — probably ice pebbles — that seem to have been rounded by erosion.

It did not appear to be raining when Huygens descended through Titan’s haze on parachutes, “but it has been raining not long ago,” Lebreton said.

The Mars Rover team already has contacted him to say that “they really now are dreaming of sending their rovers on the surface of Titan,” he added. “This is highly possible — that we can now dream seriously of sending rovers on the surface of Titan. We just need the money.”