Astrophysical ionizing radiation events have been recognized as a potential threat to life on Earth, primarily through depletion of stratospheric ozone and subsequent increase in surface-level solar ultraviolet radiation. Simulations […]
climate
Posted inBiosignatures & Paleobiology, SETI & Technosignatures
A New Approach to SETI: Targeting Alien Polluters
Humanity is on the threshold of being able to detect signs of alien life on other worlds. By studying exoplanet atmospheres, we can look for gases like oxygen and methane […]
Posted inHabitable Zones
How Earth Avoided Global Warming, Last Time Around
Geochemists have calculated a huge rise in atmospheric CO2 was only avoided by the formation of a vast mountain range in the middle of the ancient supercontinent, Pangea. This work […]
Posted inAtmospheres, Climate, Weather, Extinction events
Did A Methane Burst Cause the end-Permian Extinction?
The end-Permian extinction is associated with a mysterious disruption to Earth’s carbon cycle. Here we identify causal mechanisms via three observations. First, we show that geochemical signals indicate superexponential growth […]
Posted inHabitable Zones, Water/Hycean Worlds & Oceanography
Global Warming Felt to Deepest Reaches of Ocean
In the mid-1970s, the first available satellite images of Antarctica during the polar winter revealed a huge ice-free region within the ice pack of the Weddell Sea. This ice-free region, […]
Posted inBiogeochemical Cycles & Geobiology, Plant Biology
Symbiotic Fungi Inhabiting Plant Roots Have Major Impact on Atmospheric Carbon
Microscopic fungi that live in plants’ roots play a major role in the storage and release of carbon from the soil into the atmosphere. According to a University of Texas […]
Posted inExoplanets, -moons, -comets, Habitable Zones
Super Earths Likely To Have Both Oceans and Continents
Massive terrestrial planets, called “super-Earths,” are known to be common in our galaxy, the Milky Way. Now a Northwestern University astrophysicist and a University of Chicago geophysicist report the odds […]
Posted inBiogeochemical Cycles & Geobiology, Habitable Zones, Water/Hycean Worlds & Oceanography
Geochemical and planetary dynamical views on the origin of Earth's atmosphere and oceans
Earth’s volatile elements (H, C, and N) are essential to maintaining habitable conditions for metazoans and simpler life forms. However, identifying the sources (comets, meteorites, and trapped nebular gas) that […]
Posted inMars
Unusual Greenhouse Gases – Raising Ancient Martian Temperature?
Much like the Grand Canyon, Nanedi Valles snakes across the Martian surface suggesting that liquid water once crossed the landscape, according to a team of researchers who believe that molecular […]
Posted inHabitable Zones
Evaluating Solutions to the Faint Young Sun Problem
During the Archean eon, between about 3.8 billion years ago and 2.5 billion years ago, the Sun was about 20 to 25 percent fainter than it is today. With less […]