Habitable Zones & Global Climate

No Snowball on Habitable Tidally Locked Planets

No Snowball on Habitable Tidally Locked Planets

The TRAPPIST-1, Proxima Centauri, and LHS 1140 systems are the most exciting prospects for future follow-up observations of potentially inhabited planets. All orbit nearby M-stars and are likely tidally locked in 1:1 spin-orbit states, which motivates the consideration of the effects that tidal locking might have on planetary habitability.

Biosignatures & Paleobiology

On Signatures of Clouds in Exoplanetary Transit Spectra

On Signatures of Clouds in Exoplanetary Transit Spectra

Transmission spectra of exoplanetary atmospheres have been used to infer the presence of clouds/hazes. Such inferences are typically based on spectral slopes in the optical deviant from gaseous Rayleigh scattering or low-amplitude spectral features in the infrared.

Extrasolar Planets

Formation of Solar System Analogs

Formation of Solar System Analogs

Population synthesis models of planetary systems developed during the last ∼15 years could reproduce several of the observables of the exoplanet population, and also allowed to constrain planetary formation models. We present our planet formation model, which calculates the evolution of a planetary system during the gaseous phase.

Biosignatures & Paleobiology

Building A Mass Spectrometer To Land on Europa

Building A Mass Spectrometer To Land on Europa

An instrument originally developed to search for organic molecules on Mars is being repurposed to potentially hunt for life on a handful of moons in the outer solar system that appear to host oceans, geysers and vents of ice volcanoes.

Biosignatures & Paleobiology

Exoplanet Biosignatures: Future Directions

Exoplanet Biosignatures: Future Directions

Exoplanet science promises a continued rapid accumulation of rocky planet observations in the near future, energizing a drive to understand and interpret an unprecedented wealth of data to search for signs of life. The large statistics of exoplanet samples, combined with the ambiguity of our understanding of universal properties of life and its signatures, necessitate a quantitative framework for biosignature assessment.

Astrochemistry

Study Shows How Radioactive Decay Could Support Extraterrestrial Life

Study Shows How Radioactive Decay Could Support Extraterrestrial Life

In the icy bodies around our solar system, radiation emitted from rocky cores could break up water molecules and support hydrogen-eating microbes. To address this cosmic possibility, a University of Texas at San Antonio (UTSA) and Southwest Research Institute (SwRI) team modeled a natural water-cracking process called radiolysis

Biosignatures & Paleobiology

Exoplanet Biosignatures: Understanding Oxygen as a Biosignature in the Context of Its Environment

Exoplanet Biosignatures: Understanding Oxygen as a Biosignature in the Context of Its Environment

Here we review how environmental context can be used to interpret whether O2 is a biosignature in extrasolar planetary observations. This paper builds on the overview of current biosignature research discussed in Schwieterman et al. (2017), and provides an in-depth, interdisciplinary example of biosignature identification and observation that serves as a basis for the development of the general framework for biosignature assessment described in Catling et al., (2017).

Astrochemistry

Production of Complex Organic Molecules: H-atom Addition Versus UV Irradiation

Production of Complex Organic Molecules: H-atom Addition Versus UV Irradiation

Complex organic molecules (COMs) have been identified in different environments in star- forming regions. Laboratory studies show that COMs form in the solid state, on icy grains, typically following a non-energetic (atom-addition) or energetic (UV-photon absorption) trigger. So far, such studies have been largely performed for single processes.

Extrasolar Planets

Neutron Star Planets: Atmospheric Processes and Habitability

Neutron Star Planets: Atmospheric Processes and Habitability

Of the roughly 3000 neutron stars known, only a handful have sub-stellar companions. The most famous of these are the low-mass planets around the millisecond pulsar B1257+12. New evidence indicates that observational biases could still hide a wide variety of planetary systems around most neutron stars.

Biosignatures & Paleobiology

Exoplanet Biosignatures: Observational Prospects

Exoplanet Biosignatures: Observational Prospects

We provide an overview of the prospects for biosignature detection and general characterization of temperate Earth-sized planets. We review planned space-based missions and ground-based projects as well as the basic methods they will employ, and summarize which exoplanet properties will become observable as these new facilities come on line.

Astrobiology (general)

Before Astrobiology There Was Aстробиология

Before Astrobiology There Was Aстробиология

Contrary to what NASA may want you to think, the word "Astrobiology" was used decades before NASA began using it to describe the study of extraterrestrial life.

This book "Astrobiology" - "Aстробиология" was published (in Russian) in 1953 in the USSR.

The photos below illustrate the topics that the book covered.

More top stories from May.