A stellar revolution to characterise small planets and discover other Earths

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As an Ernest Rutherford Fellow, I seek to answer some of humanity's most fundamental questions: Are there other planets similar to Earth? What kinds of planets are habitable? Is there life elsewhere? The most viable way to discover Earth-like exoplanets is to monitor stars to look for the tiny wobbling induced by planets orbiting them. We now have the technological capability to detect these tiny wobbles. I will tackle the main remaining challenge: filtering out the "noise" that arises from the host stars. The surfaces of stars are constantly bustling with plasma flows and strong magnetic fields. This intrinsic variability contaminates observations of exoplanets and prevents us from detecting planets as small as Earth and Venus. Furthermore, stellar variability precludes us from measuring a planet's most fundamental parameter: its mass. Knowing a planet's mass allows us to study its interior composition and its atmosphere. Future observations of their atmospheres will be contaminated by the host stars' intrinsic variability. To overcome these obstacles, I will develop detailed models of stellar variability.My project begins close to home: to better understand stars, I will examine our best-known star, the Sun. I will study it as though it were a distant, point-like star. This perspective will allow me to radically advance our understanding of other stars, and to model intrinsic stellar variability to a precision well beyond today's limit. I will design analysis tools to remove stellar contamination from observations of exoplanets. This will trigger a leap forward in the study of exoplanets; it will allow me to determine their masses with unprecedented confidence, thereby enabling robust characterisation of exoplanets' atmospheres and interiors. I will make my tool available publicly. My work will maximise the ability of upcoming space missions to discover exoplanets and examine their atmospheres, including the NASA/JWST, ESA/PLATO and ESA/ARIEL missions. I am a member of the Terra Hunting Experiment, the world's first observatory to have the technological and logistical capability to detect other Earths. I will apply my analytical tools to these observations to detect terrestrial exoplanets in Venus- and Earth-like orbits. Ultimately, these discoveries will enable us to test our theories of how life shapes its host planet, and to better understand our place in the Universe.