January 2018

We estimate the capture rate of interstellar objects by means of three-body gravitational interactions. We apply this model to the Sun-Jupiter system and the Alpha Centauri A\B binary system, and find that the radius of the largest captured object is a few tens of km and Earth-sized respectively.

The ice-albedo feedback on rapidly-rotating terrestrial planets in the habitable zone can lead to abrupt transitions (bifurcations) between a warm and a snowball (ice-covered) state, bistability between these states, and hysteresis in planetary climate.

Search for different life-forms elsewhere is the fascinating area of research in astrophysics and astrobiology. Nearly 3500 exoplanets are discovered according to NASA exoplanet archive database.

As we discover numerous habitable planets around other stars in the Milky Way galaxy, including the nearest star, Proxima Centauri, one cannot help but wonder why have we not detected evidence for an advanced alien civilization as of yet.

Since the discovery of an ice-particle plume erupting from the south polar terrain on Saturn's moon Enceladus (Porco et al., 2006; Spahn et al., 2006; Spencer et al., 2006), the geophysical mechanisms driving its activity have been the focus of substantial scientific research.

The nearby dwarf galaxy known as the Large Magellanic Cloud (LMC) is a chemically primitive place. Unlike the Milky Way, this semi-spiral collection of a few tens-of-billions of stars lacks our galaxy's rich abundance of heavy elements, like carbon, oxygen, and nitrogen.

Dale Andersen sent this via inReach from Lat -69.47328 Lon 39.604897 on 30 January 2018 at 1:42:16 AM EST: "Hi Keith, we moved back to the Kizahashi Hut on Skarvsnes Island yesterday afternoon. We will start winding down the science and will begin packing up the camp soon."

How can scientists conclude with high confidence that an exoplanet hosts life? As telescopes come on line over the next 20 years that can directly observe photons from terrestrial exoplanets, this question will dictate the activities of many scientists across many fields.

A team of scientists, led by Boy Lankhaar at Chalmers University of Technology, has solved an important puzzle in astrochemistry: how to measure magnetic fields in space using methanol, the simplest form of alcohol.

Oceanic tides are a major source of tidal dissipation. They drive the evolution of planetary systems and the rotational dynamics of planets.

Dale Andersen sent this via Iridium on January 28, 2018 1:27:35 PM EST "Keith: We had a busy day here today, diving Lake Skallen. The lake had retained about half its ice-cover which made searching for and retrieving instrumentation a bit more difficult."

A key challenge in origin-of-life studies is understanding the environmental conditions on early Earth under which abiogenesis occurred.

Chemical disequilibrium in planetary atmospheres has been proposed as a generalized method for detecting life on exoplanets through remote spectroscopy.

Dale Andersen sent this message via InReach from Lat -69.673748 Lon 39.402809 at on 26 January 2018 at 12:33:21 PM EST: "Hi Keith, we made it over to Skallen earlier today during a break in the weather. Once we began snowing again so we scrambled to get gear organized and tents up."

Dale Anderson sent this message at 8:06:43 AM EST on 24 January 2018: "Keith: We completed the work at Lake Naga and are all back at our camp now."

As NASA's James Webb Space Telescope and other new giant telescopes come online they will need novel strategies to look for evidence of life on other planets.

Electron microscope images of marine bacteria infected with the non-tailed viruses studied in this research. The bacterial cell walls are seen as long double lines, and the viruses are the small round objects with dark centers.

In 2013, the European Space Agency and Roscosmos -- the Russian governmental body responsible for space research -- agreed to cooperate on ExoMars, the first joint interplanetary mission between ESA and Russia.

The search of life in the Universe is a fundamental problem of astrobiology and a major priority for NASA.

Dale Anderson sent this message at 2:53:16 PM EST on 23 January 2018: "Keith: We dove in Naga Ike (Lake Naga) a few days ago to retrieve instrumentation that had been set out a year ago."

Rutgers scientists have found the "Legos of life" - four core chemical structures that can be stacked together to build the myriad proteins inside every organism - after smashing and dissecting nearly 10,000 proteins to understand their component parts.

A dawning field of research, artificial biology, is working toward creating a genuinely new organism.

Two exoplanets in the TRAPPIST-1 system have been identified as most likely to be habitable, a paper by PSI Senior Scientist Amy Barr says.

For the first time in human history, we will soon be able to apply the scientific method to the question "Are We Alone?" The rapid advance of exoplanet discovery, planetary systems science, and telescope technology will soon allow scientists to search for life beyond our Solar System through direct observation of extrasolar planets.

Liquid water is one of the most important materials affecting the climate and habitability of a terrestrial planet.

Here we advocate an observational strategy to help prioritize exoplanet observations.

A postgraduate student of the Faculty of Geology of MSU, working with an international scientific group, participated in chemical analysis of biomarkers -- compounds that remained after the decomposition of organic remains of the genus Beltanelliformis.

Polycyclic aromatic hydrocarbons and polycyclic aromatic nitrogen heterocycles are thought to be widespread throughout the Universe, because these classes of molecules are probably responsible for the unidentified infrared bands, a set of emission features seen in numerous Galactic and extragalactic sources.

Mountain ranges, volcanoes, trenches, and craters are common on rocky bodies throughout the Solar System, and we might we expect the same for rocky exoplanets.

We perform long-term simulations, up to ten billion years, of closely-spaced configurations of 2 -- 6 planets, each as massive as the Earth, traveling on nested orbits about either stellar component in alpha Centauri AB.

The planetary building blocks that formed in the terrestrial planet region were likely very dry, yet water is comparatively abundant on Earth. We review the various mechanisms proposed for the origin of water on the terrestrial planets.

Researchers demonstrate for the first time the potential of existing technology to directly detect and characterize life on Mars and other planets

We carry out 3-D numerical simulations to assess the penetration and bombardment effects of Solar Energetic Particles (SEPs), i.e. high-energy particle bursts during large flares and superflares, on ancient and current Mars.

Saturn's moon Titan may be nearly a billion miles away from Earth, but a recently published paper based on data from NASA's Cassini spacecraft reveals a new way this distant world and our own are eerily similar.

RNA was probably the first informational molecule. Now chemists from Ludwig-Maximilians-Universitaet (LMU) in Munich have demonstrated that alternation of wet and dry conditions could have sufficed to drive the prebiotic synthesis of the RNA nucleosides found in all domains of life.

Given the fact that Earth is so far the only place in the Milky Way galaxy known to harbor life, the question arises of whether the solar system is in any way special. To address this question, I compare the solar system to the many recently discovered exoplanetary systems.

The current explosion in detection and characterization of thousands of extrasolar planets from the Kepler mission, the Hubble Space Telescope, and large ground-based telescopes opens a new era in searches for Earth-analog exoplanets with conditions suitable for sustaining life.

"Traditional SETI is not part of astrobiology" declares the NASA Astrobiology Strategy 2015 document. This is incorrect.

Dale Anderson sent this message from Lat -69.473398 Lon 39.604533 at 11:17:09 AM EST January 15, 2018 11:17:09 AM EST "Keith, quick note to provide you with our current location at The Kizahashi Hut located at Skarvsnes, one of the islands of the archipelago."

Two wayward space rocks, which separately crashed to Earth in 1998 after circulating in our solar system's asteroid belt for billions of years, share something else in common: the ingredients for life.

Scientists studying a cold molecular cloud of the Taurus region with radio telescopes have detected the presence of a particular organic molecule called benzonitrile.

10 January 2018: Southbound For Antarctica: I am now back in Cape Town, South Africa awaiting tomorrow's flight to the ice runway at Novolazarevskaya Station on the Antarctic continent.

Astronomers had a mystery on their hands. No matter where they looked, from inside the Milky Way to distant galaxies, they observed a puzzling glow of infrared light.

The goals of the astrobiology community are focussed on developing a framework for the detection of biosignatures, or evidence thereof, on objects inside and outside of our solar system.

The galactic environment has been suspected to influence planetary habitability in many ways. Very metal-poor regions of the Galaxy, or those largely devoid of atoms more massive than H and He, are thought to be unable to form habitable planets.

Future observations of terrestrial exoplanet atmospheres will occur for planets at different stages of geological evolution. We expect to observe a wide variety of atmospheres and planets with alternative evolutionary paths, with some planets resembling Earth at different epochs.

Chemists at The Scripps Research Institute (TSRI) have developed a fascinating new theory for how life on Earth may have begun. Their experiments, described today in the journal Nature Communications, demonstrate that key chemical reactions that support life today could have been carried out with ingredients likely present on the planet four billion years ago.

Colour equals information, so the more spectral bands an Earth-observing satellite sees, the greater quantity of environmental findings returned to its homeworld. Now ESA is ready to fly a hand-sized hyperspectral imager - small enough to fit on its next nanosatellite.

The extent to which a magnetosphere protects its planetary atmosphere from stellar wind ablation depends upon how well it prevents plasma from entering and how well it traps otherwise escaping plasma.

We model the evolution of ocean temperature and chemistry for rocky exoplanets with 10-1000 times Earth's H2O but without H2, taking into account C partitioning, high-pressure ice phases, and atmosphere-lithosphere exchange.

Considerable data and analysis support the detection of a supernova at a distance of about 50 pc, ~2.6 million years ago. This is possibly related to the extinction event around that time and is a member of a series of explosions which formed the Local Bubble in the interstellar medium.

The world's oldest algae fossils are a billion years old, according to a new analysis by earth scientists at McGill University.