March 2018

Could a unique bacterium be nature's microscopic power plant? Scientist Moh El-Naggar and his team think it's possible. They work with the Shewanella oneidensis species of bacteria, one of a group of microbes that essentially "breathe" rocks.

Mars has geological features that suggest it once had -- and still has -- subsurface liquid water, an almost sure prerequisite for life. Scientists have also eyed Saturn's moons Titan and Enceladus as well as Jupiter's moons Europa, Ganymede and Callisto as possible havens for life in the oceans under their icy crusts.

We describe a new approach and algorithm for the detection of artificial signals and their classification in the search for extraterrestrial intelligence (SETI).

From wispy gas giants on the verge of disruption to tiny rocky bodies already falling apart, short-period exoplanets pose a severe puzzle to theories of planet formation and orbital evolution.

Various climate states at high obliquity are realized for a range of stellar irradiance using a dynamical atmosphere-ocean-sea ice climate model in an aquaplanet configuration.

We study ocean exoplanets, for which the global surface ocean is separated from the rocky interior by a high-pressure ice mantle.

The past decade has seen major progress in our understanding of terrestrial planet formation. Yet key questions remain.

Dozens of habitable zone, approximately earth-sized exoplanets are known today.

The James Webb Space Telescope (JWST) will measure exoplanet transmission and eclipse spectroscopy at un-precedented precisions to better understand planet structure, dynamics, chemistry and formation.

A 2-billion-year-old chunk of sea salt provides new evidence for the transformation of Earth's atmosphere into an oxygenated environment capable of supporting life as we know it.

The search for habitable exoplanets inspires the question - how do habitable planets form? Planet habitability models traditionally focus on abiotic processes and neglect a biotic response to changing conditions on an inhabited planet.

The selection of optimal targets in the search for life represents a highly important strategic issue. In this paper, we evaluate the relative benefits of searching for life around a potentially habitable planet orbiting a star of arbitrary mass relative to a Sun-like star.

The Origins Space Telescope (OST) is one of four mission concepts currently being studied by NASA in preparation for the Astrophysics 2020 Decadal Survey.

Traditional definitions of the habitable zone assume that habitable planets contain a carbonate-silicate cycle that regulates CO2 between the atmosphere, surface, and the interior.

TESS is expected to discover dozens of temperate terrestrial planets orbiting M dwarfs whose atmospheres could be followed up with the James Webb Space Telescope (JWST).

TRAPPIST-1 is an ultra-cool red dwarf star that is slightly larger, but much more massive, than the planet Jupiter, located about 40 light-years from the sun in the constellation Aquarius.

Jupiter's radio emission has been linked to its planetary-scale magnetic field, and spacecraft investigations have revealed that most planets, and some moons, have or had a global magnetic field.

Space-based high contrast imaging mission concepts for studying rocky exoplanets in reflected light are currently under community study.

The stability of Earth's climate on geological timescales is enabled by the carbon-silicate cycle that acts as a negative feedback mechanism stabilizing surface temperatures via the intake and outgas of atmospheric carbon.

Our present-day atmosphere is often used as an analog for potentially habitable exoplanets, but Earth's atmosphere has changed dramatically throughout its 4.5 billion year history.

Cyclic sedimentation has varied at several timescales and this variability has been geologically well documented at Milankovitch timescales, controlled in part by climatically (insolation) driven sea-level changes.

Exoplanets mass measurements will be a critical next step to assess the habitability of Earth-like planets: a key aspect of the 2020 vision in the previous decadal survey and also central to NASA's strategic priorities.

Recent discoveries of potentially habitable exoplanets have ignited the prospect of spectroscopic investigations of exoplanet surfaces and atmospheres for signs of life.

The organic content of protoplanetary disks sets the initial compositions of planets and comets, thereby influencing subsequent chemistry that is possible in nascent planetary systems.

Because of the recent technological advances, the key technologies needed for precision space optical astrometry are now in hand.

In support of the National Acadamies' Exoplanet Science Strategy, this whitepaper outlines key technology challenges for studying the diversity of worlds in the Galaxy and in searching for habitable planets.

Astronomers at Yale University, in collaboration with Lowell Observatory, are embarking on a search that will answer one of the oldest questions in astronomy: Are there planets similar to Earth orbiting other stars?

EarthFinder is a Probe Mission concept selected for study by NASA for input to the 2020 astronomy decadal survey.

It is currently unknown how common life is on exoplanets, or how long planets can remain viable for life.

Scientists report the existence of 15 new planets -- including one 'super-Earth' that could harbor liquid water -- orbiting small, cool stars near our solar system.

For the first time, scientists from the University of Hawai'i at Mānoa (UH Mānoa) and the Monterey Bay Aquarium Research Institute (MBARI) will deploy a small fleet of long-range autonomous underwater vehicles (LRAUVs) that have the ability to collect and archive seawater samples automatically.

The discovery of a truly habitable exoplanet would be one of the most important events in the history of science.

Scientists have used lab experiments to retrace the chemical steps leading to the creation of complex hydrocarbons in space, showing pathways to forming 2-D carbon-based nanostructures in a mix of heated gases.

Take a good look at these photos: They show you 1.6 billion years old fossilized oxygen bubbles, created by tiny microbes in what was once a shallow sea somewhere on young Earth.

This is a white paper in response to the National Academy of Sciences "Exoplanet Science Strategy" call. We summarize recent advances in theoretical habitability studies and argue that such studies will remain important for guiding and interpreting observations.

Habitable planetary are commonly imagined to be temperate planets like Earth, with areas of open ocean and warm land. In contrast, planets with colder surfaces and permanent snowball states, where oceans are entirely ice-covered, are believed to be inhospitable.

Much like detectives who study fingerprints to identify the culprit, scientists used NASA's Hubble and Spitzer space telescopes to find the "fingerprints" of water in the atmosphere of a hot, bloated, Saturn-mass exoplanet some 700 light-years away.

Formation of organic aerosols driven by photochemical reactions has been observed and suggested in CH4-containing atmospheres, including Titan and early Earth.

An international research project led by the University of Granada has revealed for the first time that almost one billion viruses and more than twenty million bacteria circulate in the Earth's atmosphere and are deposited in high-mountain places every day.

NASA researchers have confirmed the existence in Titan's atmosphere of vinyl cyanide, which is an organic compound that could potentially provide the cellular membranes for microbial life to form in Titan's vast methane oceans.