Due to decreasing sunlight and worsening weather conditions, the Mars Phoenix Lander has finally ceased communications. Given that the lander started to cycle into safe mode only a little while ago, where it put itself into a mode that turned most of itself off in order to conserve power except to send regular signals, it's not too surprising that it has ceased communications. In fact, it's incredibly impressive that the little lander has lasted far longer than its original 90-day mission.
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.
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 ...
The Mars Phoenix Lander has started to shut itself down as the Martian winter approaches. With the days becoming shorter, it's getting less and less power from its solar panels that powers its electronics and its five heaters. To conserve power, it has shut down operation of its first survival heater, which had been keeping some of the lander's electronics within a reasonable temperature range.
All except one of the survival heaters will be switched off one by one as the available power decreases, with more and more instruments being exposed to temperature extremes. NASA will be stretching it out as much as possible to keep the lander operational. However, we are already seeing operations deteriorate as a power fault has forced the lander to switch to using backup systems.
In yet another demonstration of its awesomeness, the Mars Reconnaissance Orbiter managed to get an image of the Spirit rover from orbit using HiRISE, even though the rover only shows up as a dark dot. For rovers that have been on Mars for almost five years, Spirit and its twin Opportunity are still going pretty strong.
As the sun is steadily getting lower around the north pole of Mars, the Mars Phoenix Lander has managed to scoop soil into its sixth oven out of the eight that came with TEGA, the thermal and evolved-gas analyzer. Now there are two ovens left, and hopefully the lander will be able to make use of them before the sun drops below the horizon for the winter. Meanwhile, the lander would also serve as a weather station observing snow falling and clouds in the sky. And what is going on with the mystery of the unexpectedly dry Martian soil?