February 2018

This paper puts forward a possible new indicator for the presence of moderately advanced civilizations on transiting exoplanets.

The notion of a Galactic Habitable Zone (GHZ), or regions of the Milky Way galaxy that preferentially maintain the conditions to sustain complex life, has recently gained attention due to the detection of numerous exoplanets and advances made in understanding habitability on the Earth and other environments.

We continue to investigate the binary system Kepler-16, consisting of a K-type main-sequence star, a red dwarf, and a circumbinary Saturnian planet. As part of our study, we describe the system's habitable zone based on different climate models.

Name: Jennifer Eigenbrode. Formal Job Classification: Research astrobiologist. Organization: Code 699, Planetary Environments Laboratory, Space Sciences Directorate

The detection of many extrasolar gas giants with high eccentricities indicates that dynamical instabilities in planetary systems are common. These instabilities can alter the orbits of gas giants as well as the orbits of terrestrial planets and therefore eject or move a habitable planet out of the habitable zone.

For the first four billion years of Earth's history, our planet's continents would have been devoid of all life except microbes.

We explore the atmospheric and surface history of a hypothetical paleo-Venus climate using a 3-D General Circulation Model. We constrain our model with the in-situ and remote sensing Venus data available today.

Hi Keith: I am writing from sunny, warm, Cape Town, South Africa having arrived the night before last on the Il-76TD-90VD operated by Antarctic Logistics Centre International (ALCI).

Large-scale transit surveys such as NGTS, TESS and PLATO promise to deliver a wealth of potential targets for follow-up transmission spectroscopy study.

The search for an inhabited planet, other than our own, is a driver of planetary exploration in our solar system and beyond. Using information from our own planet to inform search strategies allows for a targeted search.

We predict how the C, N, and O abundances within the interstellar medium of galaxies evolve as functions of the galaxy star formation history (SFH).

As discoveries of multiple planets in the habitable zone of their parent star mount, developing analytical techniques to quantify extrasolar intra-system panspermia will become increasingly important.

This work presents theoretical studies which combine aspects of combustion and explosion theory with exoplanetary atmospheric science.

We report the first extragalactic detection of the complex organic molecules (COMs) dimethyl ether (CH3OCH3) and methyl formate (CH3OCHO) with the Atacama Large Millimeter/submillimeter Array (ALMA).

Seven temperate Earth-sized exoplanets readily amenable for atmospheric studies transit the nearby ultracool dwarf star TRAPPIST-1. Their atmospheric regime is unknown and could range from extended primordial hydrogen-dominated to depleted atmospheres.

Analysis of Kepler mission data suggests that the Milky Way includes billions of Earth-like planets in the habitable zone of their host star.

Dale Andersen sent this message via Iridium 7:24:11 AM EST 11 February 2018: "Hi Keith: 14 members of the JARE 59 summer team are returning to Novolazarevskaya today, our flight shoutouts arrived in about 15 min. I will try to track the flight with my InReach, but may not be able to get a good signal while inside. More from Novo. cheers, Dale"

February 6, 2018 3:55:35 PM EST Update: "Hi Keith, Quick note to let you know we are now at Syowa Station - depending on the weather, we will be here a few days before the flight back to Novo Station and onto Cape Town.

The seven Earth-size planets of TRAPPIST-1 are all mostly made of rock, with some having the potential to hold more water than Earth, according to a new study published in the journal Astronomy and Astrophysics.

Dale sent this message via Iridium on 5 February 2018 at 10:24:46 AM EST: "Hi Keith, Thanks for the update - we stayed inside most of the day listening to the wind blow, with average windspeeds of 40 knots gusting to 45 knots or more off and on throughout the late morning and afternoon."

Keith's note: I just sent this weather report to Dale Andersen. From these 3 webcam shots it looks like things are calmer now but it will get bad again soon as several gales continue to affect the region.

Dale sent this message via Iridium on 2 February 2018 at 4:41:48 PM EST: "Hi Keith: We returned from two days at Syowa Station and are now back in the Kizahashi Hut on Skarvsnes once again."

Keith's Note: NASA recently posted an image taken by the Mars Hand Lens Imager (MAHLI) aboard NASA's Mars rover Curiosity. A reader from Australia contacted me to point out some curious structures within the rock featured in that image.

High concentrations of heavy metals, like copper and gold, are toxic for most living creatures. This is not the case for the bacterium C. metallidurans, which has found a way to extract valuable trace elements from a compound of heavy metals without poisoning itself.

Back in the 1930s, astronomers detected one of the first molecules in interstellar space - carbynes. The simplest carbyne, formed by carbon and hydrogen only, is nowadays considered one of the most basic ingredients for life.

Previous studies have demonstrated that continental carbon-silicate weathering is important to the continued habitability of a terrestrial planet. Despite this, few studies have considered the influence of land on the climate of a tidally-locked planet.

The recent detection of Earth-sized planets in the habitable zone of Proxima Centauri, Trappist-1 and many other nearby M-type stars has led to speculations, whether liquid water and life actually exist on these planets.