Related papers: Photosynthesis on Exoplanets and Exomoons from Ref…
Small rocky planets, as well as larger planets that suffered extensive volatile loss, tend to be drier and have thinner atmospheres as compared to Earth. Such planets probably outnumber worlds better endowed with volatiles, being the most…
Here we advocate an observational strategy to help prioritize exoplanet observations. It starts with more easily obtained observational data, and ranks exoplanets for more difficult follow-up observations based on the likelihood of avoiding…
Earthshine observations offer a unique opportunity to study Earth as an exoplanet seen from the Moon. As the Sun-Earth-Moon geometry changes, Earth can be observed as a spatially unresolved exoplanet at different phase angles, providing…
The varied surfaces and atmospheres of planets make them interesting places to live, explore, and study from afar. Unfortunately, the great distance to exoplanets makes it impossible to resolve their disk with current or near-term…
One of the promising methods to search for life on extra-solar planets (exoplanets) is to detect life's signatures in their atmospheres. Spectra of exoplanet atmospheres at the modest resolution needed to search for oxygen, carbon dioxide,…
Determining the habitability and interpreting atmospheric spectra of exoplanets requires understanding their atmospheric physics and chemistry. We use a 3-D Coupled Climate-Chemistry Model, the Met Office Unified Model with the UK Chemistry…
The formation of satellites is thought to be a natural by-product of planet formation in our Solar System, and thus, moons of extrasolar planets (exomoons) may be abundant in extrasolar planetary systems, as well. Exomoons have yet to be…
We investigate the abiotic production of oxygen and its photochemical byproduct ozone through water vapor photolysis in moist atmospheres of temperate terrestrial exoplanets. The amount of water vapor available for photolysis in the middle…
We propose to search for biosignatures in the spectra of reflected light from about 100 Earth-sized planets that are already known to be orbiting in their habitable zones (HZ). For a sample of G and K type hosts, most of these planets will…
Observing habitable exoplanets that may resemble Earth is a key priority in astronomy that is dependent on not only detecting such worlds, but also ascertaining that apparent signatures of habitability are not due to other sources. Space…
Aquatic biospheres reliant on oxygenic photosynthesis are expected to play an important role on Earth-like planets endowed with large-scale oceans insofar as carbon fixation (i.e., biosynthesis of organic compounds) is concerned. We…
Planned missions will spatially resolve temperate terrestrial planets from their host star. Although reflected light from such a planet encodes information about its surface, it has not been shown how to establish surface characteristics of…
Robust atmospheric and radiative transfer modeling will be required to properly interpret reflected light and thermal emission spectra of terrestrial exoplanets. This will help break observational degeneracies between the numerous…
Exoplanets orbiting M-dwarfs within habitable zones are exposed to stellar environments more extreme than that terrestrial planets experience in our Solar System, which can significantly impact the atmospheres of the exoplanets and affect…
It is possible to learn a great deal about exoplanet atmospheres even when we cannot spatially resolve the planets from their host stars. In this chapter, we overview the basic techniques used to characterize transiting exoplanets -…
For terrestrial exoplanets with thin atmospheres or no atmospheres, the surface contributes light to the reflected light signal of the planet. Measurement of the variety of disk-integrated brightnesses of bodies in the Solar System and the…
A free-floating planet is a planetary-mass object that orbits around a non-stellar massive object (e.g. a brown dwarf) or around the Galactic Center. The presence of exomoons orbiting free-floating planets has been theoretically predicted…
Can multicellular life be distinguished from single cellular life on an exoplanet? We hypothesize that abundant upright photosynthetic multicellular life (trees) will cast shadows at high sun angles that will distinguish them from single…
As oxygen is essential for respiration and metabolism for multicellular organisms on Earth, its presence may be crucial for the development of a complex biosphere on other planets. And because life itself, through photosynthesis,…
Compared to the diversity seen in exoplanets, Venus is a veritable astrophysical twin of the Earth, however its global cloud layer truncates features in transmission spectroscopy, masking its non-Earth-like nature. Observational indicators…