Future Exoplanet Research: Science Questions and How to Address Them

Started approximately in the late 1980s, exoplanetology has up to now unveiled the main gross bulk characteristics of planets and planetary systems. In the future it will benefit from more and more large telescopes and advanced space missions. These instruments will dramatically improve their performance in terms of photometric precision, detection speed, multipixel imaging, high-resolution spectroscopy, allowing to go much deeper in the knowledge of planets. Here we outline some science questions which should go beyond these standard improvements and how to address them. Our prejudice is that one is never too speculative: experience shows that the speculative predictions initially not accepted by the community have been confirmed several years later (like spectrophotometry of transits or circumbinary planets).Comment: Invited review, accepte

Direct exoplanet investigation using interstellar space probes

Experience in exploring our own solar system has shown that direct investigation of planetary bodies using space probes invariably yields scientific knowledge not otherwise obtainable. In the case of exoplanets, such direct investigation may be required to confirm inferences made by astronomical observations, especially with regard to planetary interiors, surface processes, geological evolution, and possible biology. This will necessitate transporting sophisticated scientific instruments across interstellar space, and some proposed methods for achieving this with flight times measured in decades are reviewed. It is concluded that, with the possible exception of very lightweight (and thus scientifically limited) probes accelerated to velocities of ∼0.1c with powerful Earth-based lasers, achieving such a capability may have to wait until the development of a space-based civilization capable of leveraging the material and energy resources of the solar system