Climate change throughout the Solar System
and the Huygens lander that touched down on the satellite in 2005. “What it found shocked a lot of us – it blew people’s minds,” says Way. Like Earth there is liquid on the surface, which evaporates and condenses as rain. Yet instead of water it is methane, possibly because of the moon’s very cold temperature. Researchers have also spotted complex chemicals known to be the building blocks of life. Understanding Titan’s climate today could tell us whether it has ever had suitable conditions in the past for this chemistry to jump from prebiotic chains of molecules to full-blown biological organisms. Dragonfly could be a potential game changer in this effort. In the summer of 2019, NASA announced that it had approved the audacious rotorcraft lander that would take off and land in several sites across the Saturnian satellite, much like its insect namesake. It is due for launch in 2026 and will arrive in 2034. According to Way, climate modellers are “eagerly awaiting its arrival”.
All these efforts to understand the climates of the worlds we share the Solar System with will do more than just inform our own battle against climate change. They will also give us a better idea of what exactly makes a planet habitable in the long term. That is sorely needed in the search for life beyond the Solar System. If Venus was a pleasant planet before volcanism ran rampant, then perhaps we shouldn’t rule out planets in similar positions to Venus around other stars. Maybe there is too much focus on the idea of a habitable zone – the narrow region around a star where the temperature is right for liquid water. The contents of a planet’s atmosphere has a huge role to play in distributing heat, and surely needs to be taken into account when assessing a world’s suitability for life. Who knows, one day we may have to evacuate this planet. If so, knowing which worlds around the Sun and beyond could be new potential homes could prove vital to the continuation of our species.