Tag Archive for 'Biosphere'

An artist’s rendering of the surface of Saturn’s largest moon, Titan. Image credit: Benjamin de Bivort, debivort.org / CC BY-SA 3.0.

Titan Most Likely Non-Habitable, Astrobiologists Say

Feb 20, 2024 by News Staff

Saturn’s moon Titan has an organic-rich atmosphere and surface with a subsurface ocean that may represent a habitable environment. In a new study, astrobiologists...

Illustration of an Earth-like exoplanet after X-ray radiation exposure. Image credit: NASA / CXC / M. Weiss.

X-Ray-Luminous Supernovae Pose Threat to Earth-Like Planetary Atmospheres, Study Says

Apr 20, 2023 by News Staff

The aftermaths of supernovae always produce X-rays, but if the supernova’s blast wave strikes dense surrounding gas, it can produce a particularly large...

An artist’s impression of NASA’s Cassini spacecraft flying through plumes erupting from the south pole of Enceladus; these plumes are much like geysers and expel a combination of water vapor, ice grains, salts, methane and other organic molecules. Image credit: NASA / JPL-Caltech.

Detecting Extraterrestrial Life on Enceladus Could Be Achieved without Landing: Study

Jan 2, 2023 by News Staff

Enceladus, the sixth-biggest moon of Saturn, is a top candidate in the search for extraterrestrial life in the Solar System. An artist’s impression of...

Four possible domains of planetary intelligence: (a) on a planet with an immature biosphere (such as the Earth during the Archean Eon) there are insufficient feedback loops between life and geophysical coupled systems to exert strong co-evolution; (b) on a planet with a mature biosphere (such as Earth after the Proterozoic) the biosphere exerts strong forcing on the geophysical state establishing full co-evolution of the entire system; this feedback may provide some degree of long-term stabilizing (i.e. Gaian) modulations for the full system; (c) on a planet with an immature technosphere (represented by the current Anthropocene Earth) feedbacks from technological activity produce strong enough forcing on the coupled planetary system to drive it into new dynamical states; these forcings however are unconstrained by intention relative to the health of the civilization producing the technology; (d) on a planet with a mature technosphere, feedback loops between technological activity and biogeochemical and biogeophysical states have been intentionally modified to ensure maximum stability and productivity of the full system; alongside each planetary image, we show a schematic atmospheric spectrum; an immature biosphere would show an atmosphere mostly in equilibrium dominated perhaps by carbon dioxide (CO2); in a mature biosphere life would have changed atmospheric chemistry leading to a highly non-equilibrium state such as perhaps high concentrations of oxygen (O2); in an immature technosphere new ‘pollutant’ species appear, such as CFCs, while industrial activities such as combustion may alter the abundance of other pre-existing gases like CO2 and methane; in a mature technosphere all atmospheric constituents may have their concentrations modified to produce long-term stable and productive states for the full (civilization + biosphere) system; this is represented via a range of possible peaks for different constituents. Image credit: Frank et al., doi: 10.1017/S147355042100029X.

Can Planets Be Intelligent?

Feb 22, 2022 by News Staff

Conventionally, intelligence is seen as a property of individuals. However, it is also known to be a property of collectives. Examples include collective-decision-making...