Mars and Titan's atmosphere and interior

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Mars and Titan (Saturn's largest moon) are the two most Earth-like bodies in the solar system. Both planets have been suggested as possible locations for biological activity, either in the past, present, or future. What type of organisms might exist and whether they do exist is the topic of intense scientific debate and research. If life is found on another planet, it would have far reaching effects on the way we view our place in the universe and be one of the greatest scientific discoveries of all time. To understand the type of life that could occur on these bodies, and how we might look for it, requires in-depth knowledge of the environment of each planet. This is what I plan to focus my research on - in collaboration with major world-wide institutes such as NASA and ESA. Mars has a thin CO2 atmosphere and many surface features in common with Earth - e.g. river valleys (now dry) and sedimentary rocks. Recent evidence shows Mars was much more hospitable in the past with warmer temperatures and a thicker atmosphere, similar to Earth's early atmosphere. New results from NASA's Mars Exploration Rovers show evidence for prolonged existence of liquid water on the surface. Key to understanding this early environment is Mars' internal structure as this determined much about the surface of young Mars, including protection of the atmosphere from solar radiation, volcanoes which may have supplied much of the atmospheric gases, and interior convection/heat-flow which influenced surface geology. Knowledge of Mars' interior is currently very limited - we do not even know how big Mars' core is and whether it is liquid or solid. The best way to probe the interior is with seismology, as we do on Earth. The ExoMars mission includes a seismometer, which will use Marsquakes to probe the interior. I will calibrate and test the seismometer to ensure that the data can be interpreted properly, while simultaneously developing seismic models of Mars' interior using techniques modified from those developed for global seismology of Earth. Also key to understanding Mars' past environment is understanding the present atmosphere and climate change. It is not known if Mars' current climate is stable - water vapour migrates away from the poles each Martian summer and it is not known if it returns. One exciting possibility is that Mars is changing from one climate state to another. This question can only be answered with a combination of spacecraft and telescope observations. NASA's Mars Reconnaissance Orbiter (MRO) spacecraft is the latest and most advanced to enter orbit around Mars. I will use data from MRO to determine water and dust distribution in Mars' atmosphere and determine what effect these have on climate. Titan is an example of an Earth-like planet in the cold outer solar system. Titan has a thick atmosphere and has clouds and rain just like on Earth, but made of methane instead of water. The recent Cassini mission has shown many fascinating surface features including, methane lakes, valleys, volcanoes, and sand dunes made of tiny ice crystals. Titan's atmosphere is a breeding ground for organic molecules like benzene. Some very complicated molecules are expected to exist at the North pole, where they are protected from destruction by sun light by Titan's shadow. Cassini performed multiple flybys over the pole during 2006-2007, giving us our first ever view of this exciting region. Many of the organic molecules present in the measured infra-red spectra are yet to be identified. The global distribution of organic molecules can be used to probe Titan's atmospheric motions like the polar vortex and planet-wide circulation cells. Titan's spring equinox is in 2009 when models predict extensive and rapid changes in the atmosphere - especially at the winter pole. This pole is never visible from Earth and Cassini provides a unique opportunity to observe the polar vortex break-up, which will not be possible again for at least 30years.