We explore cloudy, extended H2-He atmosphere scenarios for the warm super-Earth GJ 1214b using an optimal estimation retrieval technique. This planet, orbiting an M4.5 star only 13 pc from the Earth, is of particular interest because it lies between the Earth and Neptune in size and may be a member of a new class of planet that is neither terrestrial nor gas giant. Its relatively flat transmiss...

The atmosphere of the Earth is opaque to most wavelengths of light in the infrared, in the ultraviolet and in the X-rays. Due to this fact observation of celestial objects in X-rays (in the range of energies from 0.5 to 20 keV) must be carried out outside the atmosphere at altitudes greater than 100 kilometers, namely from space. The development of X-ray astronomy had therefore to await the dev...

During the past 15 years, many workers employing a variety of energy sources have demonstrated the abiologic production of a large number of biologically interesting substances from many simple starting materials. Most of the experiments, however, have had a curious deficiency. While designed to elucidate origin of life on earth, they do not take into account a body of geologic information. In ...

a Joint Institute for the Study of the Atmosphere and Ocean, University of Washington, Seattle, WA, USA b Department of Geosciences, Mississippi State University, Mississippi State, MS, USA c Earth and Environmental Sciences and Lamont-Doherty Earth Observatory of Columbia University, New York, NY, USA d Department of Geological Sciences, University of Oregon, Eugene, OR, USA e Auke Bay Laborat...

Solar evolution implies, for contemporary albedos and atmospheric composition, global mean temperatures below the freezing point of seawater less than 2.3 aeons ago, contrary to geologic and paleontological evidence. Ammonia mixing ratios of the order of a few parts per million in the middle Precambrian atmosphere resolve this and other problems. Possible temperature evolutionary tracks for Ear...

Computer simulations of the evolution of the Earth's atmospheric composition and surface temperature have been carried out. The program took into account changes in the solar luminosity, variations in the Earth's albedo, the greenhouse effect, variation in the biomass, and a variety of geochemical processes. Results indicate that prior to two billion years ago the Earth had a partially reduced ...

Over several decades, atmosphere and ocean modelbased analyses have matured and proliferated, with climate modeling centers around the world generating routine real-time analyses as well as periodic retrospective reanalyses of the atmosphere and ocean state. These products support a range of scientific investigations, from initializing climate and Earth system model simulations, predictions, an...

Figure 1 shows an infra-red spectrum gathered by a satellite looking down towards the Earth from around 20km. This spectrum shows the intensity of emission plotted against frequency (wavenumber). The energy depicted is mostly radiated from the surface of the Earth, which is almost a perfect blackbody and radiates radio waves in the infra-red frequency band. The imperfections in the shape of the...

Our selection of new super greenhouse gases to fill a putative "window" in a future Martian atmosphere relies on quantum-mechanical calculations. Our study indicates that if Mars could somehow acquire an Earth-like atmospheric composition and surface pressure, then an Earth-like temperature could be sustained by a mixture of five to seven fluorine compounds. Martian mining requirements for repl...

As the most abundant hydrocarbon in the atmosphere and a powerful greenhouse gas, methane (CH4) plays an important role in both the chemical composition and radiative balance of the earth’s atmosphere. To understand it’s role in the atmosphere, its sources and sinks as well as processes governing the rates and fluxes of this gas is an important objective if we are to understand the function of ...