Related papers: The faint young Sun problem
The characterization of exoplanetary atmospheres has come of age in the last decade, as astronomical techniques now allow for albedos, chemical abundances, temperature profiles and maps, rotation periods and even wind speeds to be measured.…
Over the past two decades, enormous advances in the detection of exoplanets have taken place. Currently, we have discovered hundreds of earth-sized planets, several of them within the habitable zone of their star. In the coming years, the…
A transition to a fully global renewable energy infrastructure is potentially possible in no more than a few decades, even using current wind/solar technologies. We demonstrate that at its completion this transition would terminate…
Long-term changes in the tilt of the Earths axis, relative to the plane of its orbit, are of great significance to long-term climate change, because they control the size of the arctic and antarctic circles. These Milankovitch cycles have…
The instability with respect to global glaciation is a fundamental property of the climate system caused by the positive ice-albedo feedback. The atmospheric carbon dioxide concentration at which this Snowball bifurcation occurs changes…
The interior structure of the Sun can be studied with great accuracy using observations of its oscillations, similar to seismology of the Earth. Precise agreement between helioseismological measurements and predictions of theoretical solar…
Short-period Earth to Neptune size exoplanets (super-Earths) with voluminous gas envelopes seem to be very common. These gas atmospheres are thought to have originated from the protoplanetary disk in which the planets were embedded during…
Increasing greenhouse gases will change many aspects of the Earth's climate, from its annual mean to the frequency of extremes such as heat waves and droughts. Here we report that the current generation of climate models predicts a delay in…
The freeze-in mechanism has been shown to allow the simultaneous generation of cosmic dark matter and a viable matter-antimatter asymmetry in the universe. When the underlying interactions are described by higher-dimensional,…
We explore the conditions prevailing in primordial planets in the framework of the HGD cosmologies as discussed by Gibson and Schild. The initial stages of condensation of planet-mass H-4He gas clouds in trillion-planet clumps is set at…
Hydrogen cyanide (HCN) is crucial for the RNA World hypothesis, forming biomolecules essential for early life. Life likely emerged around 4 billion years ago during the early Archean Eon, a period on Earth with a fainter sun, frequent…
Space weather in exoplanetary systems, driven by transient stellar emissions such as flares, coronal mass ejections, and stellar proton events, can significantly influence planetary habitability and the long-term evolution of atmospheres.…
Firestone (2014) asserted evidence for numerous (23) nearby (d<300 pc) supernovae within the Middle and Late Pleistocene. If true, this would have strong implications for the irradiation of the Earth; at this rate, mass extinction level…
We present two state-of-the-art models of the solar system, one corresponding to the present day and one to the Archean Eon 3.5 billion years ago. Each model contains spatial and spectral information for the star, the planets, and the…
The fate of surface water on Venus is one of the most important outstanding problems in comparative planetology. Here a new concept is proposed to explain water removal on a steam-covered proto Venus, referred to as impact-driven planetary…
The next decade will be an exciting period for solar astrophysics, as new ground- and space-based instrumentation will provide unprecedented observations of the solar atmosphere and heliosphere. The synergy between modeling effort and…
The thermal evolution of magma oceans formed by giant impacts is strongly influenced by a proto-atmosphere through its blanketing effect, which suppresses outgoing planetary radiation. While both radiative absorption and Rayleigh scattering…
Gravitational lensing of invisible streaming matter towards the Sun could be the explanation of the puzzling solar flares and the unexplained solar emission in the EUV. Assuming that this invisible matter has some form of interaction with…
Water-rich planets such as Earth are expected to become eventually uninhabitable, because liquid water does not remain stable at the surface as surface temperatures increase with the solar luminosity over time. Whether a large increase of…
The rise of oxygen in Earth's atmosphere that occurred 2.4 to 2.2 billion years ago is known as the Earth's Great Oxidation, and its impact on the development of life on Earth has been profound. Thereafter, the increase in Earth's oxygen…