Related papers: Radiative Habitable Zones in Martian Polar Environ…
The detection of biologically important, organic molecules on Mars is an important goal that may soon be reached. However, the current small number of organic detections at the Martian surface may be due to the harsh UV and radiation…
Putative organisms on the Martian surface would be exposed to potentially high doses of ionizing radiation during strong solar X-ray flares. We extrapolate the observed flare frequency-energy release scaling relation to releases much larger…
The habitable zone (HZ) is commonly defined as the range of distances from a host star within which liquid water, a key requirement for life, may exist on a planet's surface. Substantially more CO2 than present in Earth's modern atmosphere…
Ultraviolet radiation is known to inhibit photosynthesis, induce DNA destruction and cause damage to a wide variety of proteins and lipids. In particular, UV radiation between 200-300 nm becomes energetically very damaging to most of the…
Since there are several ways planets can survive the giant phase of the host star, we examine the habitability and detection of planets orbiting white dwarfs. As a white dwarf cools from 6000 K to 4000 K, a planet orbiting at 0.01 AU would…
The habitable zone (HZ) around a star is typically defined as the region where a rocky planet can maintain liquid water on its surface. That definition is appropriate, because this allows for the possibility that carbon-based,…
Recent findings suggest Mars may have been a clement environment for the emergence of life, and may even have compared favorably to Earth in this regard. These findings have revived interest in the hypothesis that prebiotically important…
The low temperatures and high ultraviolet (UV) radiation levels at the surface of Mars today currently preclude the survival of life anywhere except perhaps in limited subsurface niches. Several ideas for making the martian surface more…
Ionizing radiation is known to have a destructive effect on biology by causing damage to the DNA, cells, and production of Reactive Oxygen Species (ROS), among other things. While direct exposure to high radiation dose is indeed not…
The Habitable Zone (HZ) is defined by the possibility of sustaining liquid water on a planetary surface. In the Solar System, the HZ for a conservative climate model extends approximately between the orbits of Earth and Mars. We elaborate…
With the discovery of rocky planets in the temperate habitable zone (HZ) of the close-by cool star TRAPPIST-1 the question of whether such planets could harbour life arises. Habitable planets around red dwarf stars can orbit in radiation…
The discovery of potentially habitable planets around the ultracool dwarf star Trappist-1 naturally poses the question: could Trappist-1 planets be home to life? These planets orbit very close to the host star and are most susceptible to…
Recognizing whether a planet can support life is a primary goal of future exoplanet spectral characterization missions, but past research on habitability assessment has largely ignored the vastly different conditions that have existed in…
With most planets and planetary candidates detected in the stellar habitable zone (HZ) being super-Earths and gas giants, rather than Earth-like planets, we naturally wonder if their moons could be habitable. The first detection of such an…
Ultraviolet radiation is a double-edged sword to life. If it is too strong, the terrestrial biological systems will be damaged. And if it is too weak, the synthesis of many biochemical compounds can not go along. We try to obtain the…
We explore the astrobiological significance of F-type stars of spectral type between F5 V and F9.5 V, which possess Jupiter-type planets within or close to their climatological habitable zones. These planets, or at least a subset of those,…
The Kepler data show that habitable small planets orbiting Red Dwarf stars (RDs) are abundant, and hence might be promising targets to look at for biomarkers and life. Planets orbiting within the Habitable Zone of RDs are close enough to be…
The intense debate about the presence of methane in the Martian atmosphere has stimulated the study of methanogens adapted to terrestrial habitats that mimic Martian environments. We examinate the environmental conditions, energy sources…
$\text{CO}_{\text{2}}$ ice clouds are important for polar energy balance and the carbon dioxide cycle on Mars. However, uncertainties remain regarding their physical and radiative properties, which control how polar $\text{CO}_{\text{2}}$…
The traditional definition of the circumstellar habitable zone (HZ) focuses on liquid water, but neglects the crucial role of ultraviolet (UV) radiation in prebiotic chemistry. Low-mass stars typically emit insufficient UV radiation for…