Project description
Signal correction key to probing Earth-like exoplanet atmospheres
NASA’s new exoplanet-hunter space telescope TESS spent two years searching for possibly habitable planets close to our solar system. Follow-up studies need to consider radii, and importantly, mass measurements to interpret the spectroscopic features in the atmospheres of Earth twins orbiting bright stars. Radial velocity spectrometers, which measure the gravitational influence of an exoplanet on its host star, are ideal for mass measurements. However, perturbing signals induced by the host star and Earth’s atmosphere can completely mask the signal emitted by an Earth twin. The goal of the EU-funded SCORE project is to analyse the data stemming from two telescopes that feed sunlight into radial velocity instruments and investigate how to mitigate the different perturbing signals.
Objective
Searching for life signatures on another planet is one of the key endeavours of astrophysics and today, we are in a unique position to make this possible. The TESS satellite, which just started observing, will find the first Earth-twins orbiting bright stars, which will allow follow-up studies with JWST and ELTs to characterize the atmosphere of those exoplanets. However, TESS will only measure the radius of the detected Earth-twins, which is not enough to interpret the spectroscopic features in their atmospheres. The mass is also required, and it can be obtained using the radial-velocity (RV) technique, which measures the gravitational influence of an exoplanet on its host star. To measure the mass of the Earth-twins that TESS will detect, the community have built incredible RV instruments that can reach a RV precision of 0.25 m/s (ESPRESSO commissioning). Such an extreme precision is required to measure the tiny signature of an Earth-twin, however, this is without considering the perturbing signals induced by its host star, by Earth’s atmosphere and by instrumental noise. Indeed, we know that these perturbing signals mask completely the signal induced by an Earth-twin, and now that the RV instruments have the sensitivity to detect such planets, it is urgent to develop novel methods for mitigating the different perturbing signals. Understanding the different perturbing signals is extremely challenging and require incredible data. The PI have built two telescopes that feed Sun-light into the best RV instruments. The obtained data are of exceptional quality, and the goal of SCORE is to analyse them, explore novel promising methods for mitigating the different perturbing signals and find the tiny signatures of Earth and Venus. This will open the way towards the mass-measurement of Earth-twins, which is essential in the quest for finding life elsewhere, but also to understand planetary formation and dynamics. SCORE will therefore benefit the entire planet community.
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Funding Scheme
ERC-STG - Starting GrantHost institution
1211 Geneve
Switzerland