Related papers: Clouds can enhance direct imaging detection of O2 …
A planet's spectrum is dynamic and only represents a time-dependent snapshot of its properties. Changing atmospheric conditions due to climate and weather patterns, particularly variation in cloud cover, can significantly affect the…
Oxygen is a well-studied biosignature. Studying potential abiotic pathways for O2 build-up in exoplanet atmospheres is essential for evaluating whether the detection of O2 would constitute a biosignature detection on other worlds. Previous…
In the near-future, atmospheric characterization of Earth-like planets in the habitable zone will become possible via reflectance spectroscopy with future telescopes such as the proposed LUVOIR and HabEx missions. While previous studies…
One of the most outstanding issues in exoplanet characterization is understanding the prevalence of obscuring clouds and hazes in their atmospheres. The ability to predict the presence of clouds/hazes a priori is an important goal when…
Direct imaging spectroscopy with future space-based telescopes will constrain terrestrial planet atmospheric composition and potentially detect biosignature gases. One promising indication of life is abundant atmospheric O2. However,…
We study the influence of low-level water and high-level ice clouds on low-resolution reflection spectra and planetary albedos of Earth-like planets orbiting different types of stars in both the visible and near infrared wavelength range.…
As a test-bed for future investigations of directly imaged terrestrial exoplanets, we present the recovery of the surface components of the Earth from multi-band diurnal light curves obtained with the EPOXI spacecraft. We find that the…
The strongest remotely detectable signature of life on our planet today is the photosynthetically produced oxygen (O2) in our atmosphere. However, recent studies of Earth's geochemical proxy record suggest that for all but the last ~500…
Many planetary parameters impact the climate state of Earth-like exoplanets and could vary significantly from those on Earth. However, some of these parameters may be impossible to observe, causing ambiguity in determining exoplanet climate…
Earth-like, potentially habitable exoplanets are prime targets in the search for extraterrestrial life. Information about their atmosphere and surface can be derived by analyzing light of the parent star reflected by the planet. We…
The atmospheres and surfaces of planets show tremendous amount of spatial variation, which has a direct effect on the spectrum of the object, even if this may not be spatially resolved. Here, we apply hyper realistic radiative simulations…
Future direct-imaging exoplanet missions such as WFIRST/AFTA, Exo-C, and Exo-S will measure the reflectivity of exoplanets at visible wavelengths. The exoplanets to be observed will be located further away from their parent stars than is…
The search for life outside our solar system is at the forefront of modern astronomy, and telescopes such as the Habitable Worlds Observatory (HWO) are being designed to identify biosignatures. Molecular oxygen, O$_2$, is considered a…
Future space-based direct imaging missions will perform low-resolution (R$<$100) optical (0.3-1~$\mu$m) spectroscopy of planets, thus enabling reflected spectroscopy of cool giants. Reflected light spectroscopy is encoded with rich…
The characterization of nearby rocky exoplanets will become feasible with the next generation of telescopes, such as the Extremely Large Telescope (ELT) and the mission concept Habitable Worlds Observatory (HWO). Using an improved model…
Direct-imaging observations of terrestrial exoplanets will enable their atmospheric characterization and habitability assessment. Considering the Earth, the key atmospheric signatures for the biosphere is O$_2$ and the photochemical product…
Future astrophysics missions will seek extraterrestrial life via transmission and direct imaging observations. To assess habitability and biosignatures, we need robust retrieval tools to analyze observed spectra, and infer surface and…
Carbon Dioxide (CO2) is one of the most important greenhouse gases after water vapor (H2O) which plays significant role in the climate process. Accurate space-based measurement of CO2 is of great significance in inferring the location of…
The search for life on planets outside our solar system will use spectroscopic identification of atmospheric biosignatures. The most robust remotely-detectable potential biosignature is considered to be the detection of oxygen (O_2) or…
Space-based ultra-high-energy cosmic ray detectors observe fluorescence light from extensive air showers produced by these particles in the troposphere. Clouds can scatter and absorb this light and produce systematic errors in energy…