The seas of Saturn’s moon Titan have bizarre “magic islands” that appear to look and disappear over the course of hours to weeks. These so-called islands would possibly truly be porous, sponge-like clumps of snow that slowly replenish with fluid after which sink.

Titan’s thick ambiance is stuffed with advanced natural molecules that may clump collectively and fall all the way down to the moon’s floor like snow. Xinting Yu on the College of Texas at San Antonio and her colleagues thought the “snow” could possibly be answerable for the magic islands. To check their concept, they used what we learn about these atmospheric compounds and the way they’re anticipated to work together with Titan’s seas.

Usually, we count on any solids on the surfaces of those seas to sink instantly as a result of the liquid on Titan is methane moderately than water. Whereas water molecules are likely to cling to 1 one other and push away different supplies, methane simply grabs on to different molecules, so a pool of liquid methane has little or no floor pressure.

“Water molecules simply love themselves to the exclusion of some varieties of molecules,” says Michael Malaska at NASA’s Jet Propulsion Laboratory in California, who was not concerned on this work. “However put methane on the identical floor and it’ll crawl throughout.” That signifies that the methane oceans and lakes on Titan ought to instantly swallow up any solids, even people who would possibly in any other case be anticipated to drift.

However that clearly doesn’t occur with the magic islands, which appeared as ephemeral vivid spots in observations from the Cassini spacecraft. “For us to see the magic islands, they’ll’t simply float for a second after which sink,” Yu mentioned in a statement. “They should float for a while, however not for perpetually, both.”

The researchers discovered an answer to this downside: if giant chunks of snow amassed on the shore, they might kind ices which might be stuffed with holes, like sponges. When these porous “icebergs” broke off from the land, they might float on Titan’s seas for lengthy sufficient to match the Cassini observations. This may work if, the researchers calculated, the sponge-like constructions contained sufficient empty area – a minimal of about 25 to 50 per cent relying on the precise composition of the ice.

This doesn’t imply that the mysterious islands are positively porous icebergs, although. “We’re narrowing the totally different situations for the magic islands, however we nonetheless don’t but know the reply,” says Malaska. Different doable explanations embrace bubbles of nitrogen gasoline, waves attributable to wind or stable sediments within the oceans. However this does present proof that Titan’s transitory islands may truly be floating matter from this unusual world’s ambiance.