Astrochemistry

Gas Phase Chemistry of Cool Exoplanet Atmospheres: Insight from Laboratory Simulations

Gas Phase Chemistry of Cool Exoplanet Atmospheres: Insight from Laboratory Simulations

Photochemistry induced by stellar UV flux should produce haze particles in exoplanet atmospheres. Recent observations indicate that haze and/or cloud layers exist in the atmospheres of exoplanets.

Extrasolar Planets

Stellar Activity Analysis of Barnard's Star

Stellar Activity Analysis of Barnard's Star

The search for Earth-like planets around late-type stars using ultra-stable spectrographs requires a very precise characterization of the stellar activity and the magnetic cycle of the star, since these phenomena induce radial velocity (RV) signals that can be misinterpreted as planetary signals.

Astrochemistry

Planets With Oxygen Don't Necessarily Have Life

Planets With Oxygen Don't Necessarily Have Life

In their search for life in solar systems near and far, researchers have often accepted the presence of oxygen in a planet's atmosphere as the surest sign that life may be present there. A new Johns Hopkins study, however, recommends a reconsideration of that rule of thumb.

Habitable Zones & Global Climate

Albedos, Equilibrium Temperatures, and Surface Temperatures of Habitable Planets

Albedos, Equilibrium Temperatures, and Surface Temperatures of Habitable Planets

The potential habitability of known exoplanets is often categorized by a nominal equilibrium temperature assuming a Bond albedo of either 0.3, similar to Earth, or 0.

TRAPPIST-1

Predicting the Extreme Ultraviolet Radiation Environment of Exoplanets Around Low-Mass Stars: the TRAPPIST-1 System

Predicting the Extreme Ultraviolet Radiation Environment of Exoplanets Around Low-Mass Stars: the TRAPPIST-1 System

The high energy radiation environment around M dwarf stars strongly impacts the characteristics of close-in exoplanet atmospheres, but these wavelengths are difficult to observe due to geocoronal and interstellar contamination.

Astrochemistry

Late Delivery of Nitrogen to Earth

Late Delivery of Nitrogen to Earth

Atmospheric nitrogen may be a necessary ingredient for the habitability of a planet since its presence helps to prevent water loss from a planet. The present day nitrogen isotopic ratio, 15N/14N, in the Earth's atmosphere is a combination of the primitive Earth's ratio and the ratio that might have been delivered in comets and asteroids.

Space Life Science

Understanding Aging and Muscle Loss in Space

Understanding Aging and Muscle Loss in Space

In space, the human body loses muscle mass. Although living in microgravity requires no heavy lifting, this loss of muscle reduces physical performance.

Oceanic Research

New Undersea Maps Lead To Hydrothermal Vent And Species Discoveries

New Undersea Maps Lead To Hydrothermal Vent And Species Discoveries

A spectacular new hydrothermal vent field, named JaichMatt, has been discovered during an expedition aboard Schmidt Ocean Institute's R/V Falkor.

Dale Andersen's Field Reports

Astrobiologist Dale Andersen Antarctic Status Report 15 December 2018: Back at Novolazarevskaya Station

Astrobiologist Dale Andersen Antarctic Status Report 15 December 2018: Back at Novolazarevskaya Station

"The camp at Lake Untersee is now closed, we pulled the last three tents down early yesterday morning and completed packing our cargo into the sea container with the remainder going onto the other two cargo sleds."

Impact events

Did Supernovae Kill Off Large Ocean Animals at Dawn of Pleistocene?

Did Supernovae Kill Off Large Ocean Animals at Dawn of Pleistocene?

About 2.6 million years ago, an oddly bright light arrived in the prehistoric sky and lingered there for weeks or months. It was a supernova some 150 light-years away from Earth.

Origin & Evolution of Life

The Trails Left By Earth's First Land Animals

The Trails Left By Earth's First Land Animals

Our understanding of when the very first animals started living on land is helped by identifying trace fossils--the tracks and trails left by ancient animals--in sedimentary rocks that were deposited on the continents.

More top stories from December.