NASA Saturn's Titan: Cassini spots tropical lagoons of Methane

Tropical lakes observed by Cassini. Credit: NASA

Planetary scientists have been surprised by the discovery of exotic lagoons in the tropics of Saturn's largest moon Titan.

These are not sun-kissed holiday spots however, but long-standing little lakes of methane beneath the satellites poisonous smog.

They come as a surprise because it had been thought that such wet areas would be found only around the poles due to circulation patterns within Titan's atmosphere.

Titan fascinates because, despite the unfriendly nature of its chemistry, it shows remarkable similarities to surface features and weather on our own planet.

This is largely because this distant moon is the only satellite in the Solar System to have a dense atmosphere. There it rains methane rather than water, with the liquid circulating in a way similar to the Earth's hydrological cycle.

Europe achieved a major space success in 2005 with the soft-landing of a space probe, Huygens, which had been carried there by NASA's Cassini mission to Saturn. The lander sent back pictures and other data about the region where it landed that suggested it might be a damp former lake bed with a consistency similar to creme brulee.