May 2019

One element is the backbone of all forms of life we've ever discovered on Earth: carbon.

Where did the Earth's water come from? Although comets, with their icy nuclei, seem like ideal candidates, analyses have so far shown that their water differs from that in our oceans.

High obliquity planets represent potentially extreme limits of terrestrial climate, as they exhibit large seasonality, a reversed annual-mean pole-to-equator gradient of stellar heating, and novel cryospheres.

Newly discovered layers of ice buried a mile beneath Mars' north pole are the remnants of ancient polar ice sheets and could be one of the largest water reservoirs on the planet, according to scientists at The University of Texas at Austin and the University of Arizona.

Astronomers using the Gemini Observatory explore Neptune's largest moon Triton and observe, for the first time beyond the lab, an extraordinary union between carbon monoxide and nitrogen ices.

Scientists may have found a way to tell if alien worlds have a climate that is suitable for life by analyzing the light from these worlds for special signatures that are characteristic of a life-friendly environment.

The climate history of the earth is marked by periodic changes that are usually ascribed to the solar radiation reaching the surface of the earth. This insolation is not constant over geological time but modulated by cyclic changes in the earth's orbital parameters.

Scientists at Université de Montréal and McGill University have pioneered and tested a new genomic methodology which reveals a complex bacterial ecosystem at work on the International Space Station.

Most living things have a suite of genes dedicated to repairing their DNA, limiting the rate at which their genomes change through time.

A team of international scientists--including researchers at the University of St. Andrews, Syracuse University and Royal Holloway, University of London--have demonstrated a new source of food for early life on the planet.

The Earth is unique in our solar system: It is the only terrestrial planet with a large amount of water and a relatively large moon, which stabilizes the Earth's axis.

At the low temperatures (∼10 K) and high densities (∼100,000 H2 molecules per cc) of molecular cloud cores and protostellar envelopes, a large amount of molecular species (in particular those containing C and O) freeze-out onto dust grain surfaces.

High Definition Astrometry (0.1 - 1.0 micro-arcseconds) will open a new window into neighboring planetary systems. For the first time, the realm of temperate terrestrial worlds will be explored.

We study the chemical evolution of H2O:CO:NH3 ice mixtures irradiated with soft X-rays, in the range 250-1250 eV. We identify many nitrogen-bearing molecules such as e.g., OCN-, NH4+ , HNCO, CH3CN, HCONH2, and NH2COCONH2.

Non-thermal desorption from icy grains containing H2CO has been invoked to explain the observed H2CO gas phase abundances in ProtoPlanetary Disks (PPDs) and Photon Dominated Regions (PDRs).

The James Webb Space Telescope (JWST) will offer the first opportunity to characterize terrestrial exoplanets with sufficient precision to identify high mean molecular weight atmospheres, and TRAPPIST-1's seven known transiting Earth-sized planets are particularly favorable targets.

We study temporal variations of the emission lines of Halpha, Hepsilon, H and K Ca II, D1 and D2 Na I, 4026 and 5876 A He I in the HARPS spectra of Proxima Centauri across an extended time of 13.2 years, from May 27, 2004, to September 30, 2017.

We are now on a clear trajectory for improvements in exoplanet observations that will revolutionize our ability to characterize their atmospheric structure, composition, and circulation, from gas giants to rocky planets.

We present the result of calculations to optimize the search for molecular oxygen (O2) in Earth analogs transiting around nearby, low-mass stars using ground-based, high-resolution, Doppler shift techniques.

The interior composition of exoplanets is not observable, limiting our direct knowledge of their structure, composition, and dynamics.

Formic acid (HCOOH) and carbon dioxide (CO2) are simple species that have been detected in the interstellar medium.

We describe a software package called VPLanet that simulates fundamental aspects of planetary system evolution over Gyr timescales, with a focus on investigating habitable worlds.

Kepler-62f is the first exoplanet small enough to plausibly have a rocky composition orbiting within the habitable zone (HZ) discovered by the Kepler Mission.

We describe the circumstances that led to the discovery of Kepler-36b, and the subsequent characterization of its host planetary system.

We present follow-up observations of the K2-133 multi-planet system. Previously, we announced that K2-133 contained three super-Earths orbiting an M1.5V host star - with tentative evidence of a fourth outer-planet orbiting at the edge of the temperate zone.

A number of recent experimental studies have shown that solid-state complex organic molecules (COMs) can form under conditions that are relevant to the CO freeze-out stage in dense clouds.

The current progress in the detection of terrestrial type exoplanets has opened a new avenue in the characterization of exoplanetary atmospheres and in the search for biosignatures of life with the upcoming ground-based and space missions.

Transmission spectroscopy is an important technique to probe the atmospheres of exoplanets.

Exploring diverse planetary atmospheres requires modeling tools that are both accurate and flexible.

Saturn's largest moon, Titan, is a hotbed of organic molecules, harboring a soup of complex hydrocarbons similar to that thought to have existed over four billion years ago on the primordial Earth.

Here we describe a story behind the discovery of Kepler-46, which was the first exoplanetary system detected and characterized from a method known as the transit timing variations (TTVs).

Over the past three decades instruments on the ground and in space have discovered thousands of planets outside the solar system.

The dynamic quadrupole Love number of Titan measured by Cassini is k2,obs=0.616±0.067, strongly indicating a global subsurface ocean.

Regolith on Mars exchanges water with the atmosphere on a diurnal basis and this process causes significant variation in the abundance of water vapor at the surface.

The poor stickiness of silicate dust grains is a major obstacle to the formation of rocky planetesimals.

In a recent paper in this journal, Lingam and Loeb (2018) develop an excellent heuristic for searches for biosignatures vs. technosignatures.

Studies on extraterrestrial civilisations in Russia date back to the end of the 19th century. The modern period of SETI studies began in the USSR in the early 1960s.

Extreme fluctuations in atmospheric oxygen levels corresponded with evolutionary surges and extinctions in animal biodiversity during the Cambrian explosion, finds new study led by UCL and the University of Leeds.

The International Space Station is the platform to study a variety of fields without gravity getting in the way. A new experiment is furthering the Station's capabilities for investigating exobiology (astrobiology), or the study of life in space.

We investigate the detectability of atmospheric spectral features of Earth-like planets in the habitable zone (HZ) around M dwarfs with the future James Webb Space Telescope (JWST).

The Planetary Science Division intends to solicit Interdisciplinary Consortia for Astrobiology Research (ICAR) to support the goal of the NASA's Astrobiology program in the study of the origins, evolution, and distribution of life in the universe.

A new study examines lipid biomarkers in modern microbial mat ecosystems in order to gain insight into the ancient biomarker record.

A recent study explores the potential for diamidophosphate (DAP) to form naturally on the early Earth.

We report Spitzer Space Telescope observations during predicted transits of the exoplanet Proxima Centauri b.

Even though there are planned missions to explore Jupiter's moon Europa, they are unlikely to sample the depths of its potentially habitable ocean

New research has identified manganese as an unsung hero in the evolution of life on Earth, as it enabled a form of pre-oxygen photosynthesis and helped protect against cellular oxidation.

A new study provides deeper insight into the chemical and isotopic signatures in Earth's geological record by resurrecting ancient enzymes to better understand the processes by which they were formed.

Which of Earth's features were essential for the origin and sustenance of life? And how do scientists identify those features on other worlds?

Astronauts on future long-duration spaceflight missions to the Moon and Mars could rely on microalgae to supply essentials including food, water and oxygen.

Titan, Saturn's largest moon, has a dense atmosphere, together with lakes and seas of liquid hydrocarbons.

Rain, seas and a surface of eroding organic material can be found both on Earth and on Saturn's largest moon, Titan. However, on Titan it is methane, not water, that fills the lakes with slushy raindrops.

Two cosmochemists at Arizona State University have made the first-ever measurements of water contained in samples from the surface of an asteroid. The samples came from asteroid Itokawa and were collected by the Japanese space probe Hayabusa.