Recently in the Biosignatures & Paleobiology Category

Ocean-atmosphere chemistry on Earth has undergone dramatic evolutionary changes through its long history, with potentially significant ramifications for the emergence and long-term stability of atmospheric biosignatures.

The atmospheres of exoplanets reveal all their properties beyond mass, radius, and orbit. Based on bulk densities, we know that exoplanets larger than 1.5 Earth radii must have gaseous envelopes, hence atmospheres.

Nitrogen is a major nutrient for all life on Earth and could plausibly play a similar role in extraterrestrial biospheres.

New research from North Carolina State University shows that a 75-million-year-old Mongolian oviraptor, preserved while brooding its eggs, also preserved the original keratinous claw sheath that covered its digits.

A sensing technique that the U.S. military currently uses to remotely monitor the air to detect potentially life-threatening chemicals, toxins, and pathogens has inspired a new instrument that could "sniff" for life on Mars and other targets in the solar system -- the Bio-Indicator Lidar Instrument, or BILI.

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 our planet's long habitable history.

How did Early Earth Stay Warm?

For at least a billion years of the distant past, planet Earth should have been frozen over but wasn't. Scientists thought they knew why, but a new modeling study from the Alternative Earths team of the NASA Astrobiology Institute has fired the lead actor in that long-accepted scenario.

In an extraordinary find, a team of Australian researchers have uncovered the world's oldest fossils in a remote area of Greenland, capturing the earliest history of the planet and demonstrating that life on Earth emerged rapidly in the planet's early years.

Habitability for planets orbiting active stars has been questioned. Especially, planets in the Habitable Zone (HZ) of M-stars, like our closest star Proxima Centauri, experience temporal high-ultraviolet (UV) radiation.

The search for habitable, alien worlds needs to make room for a second "Goldilocks," according to a Yale University researcher.