Phase 3 – Working Group 5
WG5: How to robustly detect characterisable Earth-analogues
The pathways to a robust detection and characterisation of an Earth analogue, defined as a planet below ~5 Earth-masses orbiting in the habitable zone of its host star, is still uncertain. Our best chance for characterisation is likely to use a combination of high-resolution spectroscopy and high-contrast imaging for nearby planets. However, in this case, candidates should be found using extreme precision RV or transit measurements, but these measurements are currently limited by stellar signals, and the rarity of transits of long-period planets. This WG will therefore study the limitations and best techniques to overcome those issues. This working group wants also to focus on how formation and evolution models can be used to estimate in which systems Earth-mass planets are more likely to exist, as a function of the stellar properties and properties of other, easier to observe, planets in the same system. With experts in the field of extreme precision in photometry and radial velocity, coupling high-contrast imaging and high-resolution spectroscopy, modelling of planetary formation and stellar physics, this WG wants to address the following questions:
- How can we optimise observational strategies and mitigate stellar signals to detect Earth-analogues?
- Which planets can be considered to be an Earth analogue?
- Can theoretical models, by studying the best environments for Earth-analogue formation, can tell us where to search for?
- What could we learn from the atmosphere using transit spectroscopy, secondary eclipse or a combination of high-resolution spectroscopy and high-contrast imaging
