New lakes on Titan

Titan, the largest moon of the planet Saturn, is a pretty wet place. But it's not wet with water. Titan is so cold that the moon even has lakes of liquid methane and even rains down methane. Observations by the Cassini spacecraft in 2004 and 2005 saw a lake of liquid methane form where there was none before. And given the presence of clouds, not made out of water but out of methane, it's reasonable to conclude that the lake was created by a downpour of liquid methane rain.

Changes in Titan's Lakes
Changes in Titan's Lakes

I must be really easy to impress, since the thought of rain on another world is kind of exciting, especially since it's not the kind of rain we're used to on our own planet. And there's enough rain on Titan to create an entire lake within a year. Perhaps in the far future when humans have colonized Titan, we might see vacationing people diving into the cold methane lakes ...

Replenishing methane on Mars

Methane in an atmosphere is something that astronomers look for as a possible sign of life. So its discovery in the atmosphere of Mars four years ago would understandably cause a bit of excitement. But there are other possibilities of what might be producing methane on Mars, so concluding the existence of life would be premature.

Nili Fossae, a methane hotspot
Nili Fossae, a methane hotspot

Things became even more interesting when it was recently discovered that methane is produced around a few hotspots around Mars, and that these pockets of methane would dissipate within just a few years without replenishment. This means that there's something around these hotspots creating a lot of methane, either biological or chemical. Surprisingly, only one hypothesis for a chemical process is being put forward, methane clathrates, which is frozen water with a high concentration of trapped methane. Even if it turns out the methane is created from such a "mundane" chemical source, it would still be exciting since methane hotspots would also be water hotspots.

The only other possibility put forward so far is that the methane is generated by microbiological life, similar to the methanogens found on our own Earth. Or the hotspots could even be small surviving colonies of methane-exhaling Martians who evolved from methanogens, in contrast to oxygen-breathing animals such as ourselves that evolved from aerobes. The latter is way too far-fetched, but it's a fun thought to contemplate ...