Archives

May 2021


New research and computer modeling show that volcanic activity may have occurred on the seafloor of Jupiter's moon Europa in the recent past - and may still be happening.

A diverse microbial community has adapted to an extremely salty environment deep in the Red Sea. The microbes, many unknown to science, occupy a one-meter-thick area overlying the Suakin Deep, an expansive 80-meter-deep brine lake, 2,771 meters below the central Red Sea.

Interactions between the winds of stars and the magnetospheres and atmospheres of planets involve many processes, including the acceleration of particles, heating of upper atmospheres, and a diverse range of atmospheric loss processes.

Fifty-six million years ago, as the Earth's climate warmed by five to eight degrees C, new land mammals evolved, tropical forests expanded, giant insects and reptiles appeared and the chemistry of the ocean changed.

I estimate the detectability of nightside city lights on habitable, Earth-like, exoplanets around nearby stars using direct-imaging observations from the proposed LUVOIR and HabEx observatory architectures.

Considering the huge computational resources required by smoothed particle hydrodynamics (SPH) simulations and the overestimation of post-collision materials from perfect merging, we develop a statistical method to deal with collisions during the formation of planetary systems by introducing random material loss.

Chondrites are rocky fragments of asteroids that formed at different times and heliocentric distances in the early solar system. Most chondrite groups contain water-bearing minerals, attesting that both water-ice and dust were accreted on their parent asteroids.

Cell membranes are a key element of life because they keep the genetic material and metabolic machinery together. All present cell membranes are made of phospholipids, yet the nature of the first membranes and the origin of phospholipids are still under debate.

The tracking of symmetry-breaking events in space is a longlasting goal of astrochemists, aiming at an understanding of homochiral Earth chemistry. One current effort at this frontier aims at the detection of small chiral molecules in the interstellar medium.

The ion escape of Mars' CO2 atmosphere caused by its dissociation products C and O atoms is simulated from present time to ≈4.1 billion years ago (Ga) by numerical models of the upper atmosphere and its interaction with the solar wind.

When scientists hunt for life, they often look for biosignatures, chemicals or phenomena that indicate the existence of present or past life. Yet it isn't necessarily the case that the signs of life on Earth are signs of life in other planetary environments. How do we find life in systems that do not resemble ours?

A NASA team has found that organic salts are likely present on Mars. Like shards of ancient pottery, these salts are the chemical remnants of organic compounds, such as those previously detected by NASA's Curiosity rover.

Scientists have long thought that there was a direct connection between the rise in atmospheric oxygen, which started with the Great Oxygenation Event 2.5 billion years ago, and the rise of large, complex multicellular organisms.

Scientists led by Michael Ackerson, a research geologist at the Smithsonian's National Museum of Natural History, provide new evidence that modern plate tectonics, a defining feature of Earth and its unique ability to support life, emerged roughly 3.6 billion years ago.

Galactic cosmic rays are energetic particles important in the context of life. Many works have investigated the propagation of Galactic cosmic rays through the Sun's heliosphere. However, the cosmic ray fluxes in M dwarf systems are still poorly known.

We investigate the possibility of detecting artificial lights from Proxima b's dark side by computing light curves from the planet and its host star.

On May 14, the National Oceanic and Atmospheric Administration (NOAA) ship Okeanos Explorer will depart from Port Canaveral in Florida on a two-week expedition led by NOAA Ocean Exploration, featuring the technology demonstration of an autonomous underwater vehicle.

We present a new method to assess the properties of transiting planet candidates by multicolor photometry.

Nowadays, we know thousands of exoplanets, some of them potentially habitable. Next technological facilities (JWST, for example) have exoplanet atmosphere analysis capabilities, but they also have limits in terms of how many targets can be studied.

Exoplanets on eccentric orbits experience an incident stellar flux that can be markedly larger at periastron versus apoastron. This variation in instellation can lead to dramatic changes in atmospheric structure in regions of the atmosphere where the radiative and advective heating/cooling timescales are shorter than the orbital timescale.

Brown dwarfs are essential targets for understanding planetary and sub-stellar atmospheres across a wide range of thermal and chemical conditions. As surveys continue to probe ever deeper, and as observing capabilities continue to improve, the number of known Y dwarfs -- the coldest class of sub-stellar objects, with effective temperatures below about 600 K -- is rapidly growing.

While scientists have amassed considerable knowledge of the rocky planets in our solar system, like Earth and Mars, much less is known about the icy water-rich planets, Neptune and Uranus.

Stanford researchers have discovered a new kind of biomolecule that could play a significant role in the biology of all living things. The novel biomolecule, dubbed glycoRNA, is a small ribbon of ribonucleic acid (RNA) with sugar molecules, called glycans, dangling from it.

Cyanobacteria are one of the unsung heroes of life on Earth. They first evolved to perform photosynthesis about 2.4 billion years ago, pumping tons of oxygen into the atmosphere - a period known as the Great Oxygenation Event - which enabled the evolution of multicellular life forms.

High-temperature and high-pressure experiments involving a diamond anvil and chemicals to simulate the core of the young Earth demonstrate for the first time that hydrogen can bond strongly with iron in extreme conditions.

Scientists have begun the search for extraterrestrial life in the Solar System in earnest, but such life may be subtly or profoundly different from Earth-life, and methods based on detecting particular molecules as biosignatures may not apply to life with a different evolutionary history.

The Galileo mission to Jupiter discovered magnetic signatures associated with hidden sub-surface oceans at the moons Europa and Callisto using the phenomenon of magnetic induction. These induced magnetic fields originate from electrically conductive layers within the moons and are driven by Jupiter's strong time-varying magnetic field.

Martian subsurface habitability and astrobiology can be evaluated via a lava tube cave, without drilling. MACIE addresses two key goals of the Decadal Survey (2013-2022) and three MEPAG goals.

Saturn's E ring consists of micron-sized particles launched from Enceladus by that moon's geological activity. A variety of small-scale structures in the E-ring's brightness have been attributed to tendrils of material recently launched from Enceladus.

The Sturtian Snowball Earth glaciation (717~660 million years ago) represents the most severe icehouse climate in Earth's history. Geological evidence indicates that, during this glaciation, ice sheets extended to low latitudes, and model simulations suggest global frozen ocean as well as a prolonged shut-down of the hydrological cycles.

2003 was a big year for virologists. The first giant virus was discovered in this year, which shook the virology scene, revising what was thought to be an established understanding of this elusive group and expanding the virus world from simple, small agents to forms that are as complex as some bacteria.

The prospects for life on a given planet depend not only on where it forms but also how, according to Rice University scientists.

An international team of researchers led by Alice Booth (Leiden University, the Netherlands) have discovered methanol in the warm part of a planet-forming disk.

The chemical pathways linking the small organic molecules commonly observed in molecular clouds to the large, complex, polycyclic species long-suspected to be carriers of the ubiquitous unidentified infrared emission bands remain unclear.

The structure of the icy shells of ocean worlds is important for understanding the stability of their underlying oceans as it controls the rate at which heat can be transported outward and radiated to space.

The atmospheres of synchronously rotating exoplanets are intrinsically three-dimensional, and fast vertical and horizontal winds are expected to mix the atmosphere, driving the chemical composition out of equilibrium.

Evidence of recent volcanic activity on Mars shows that eruptions could have taken place within the past 50,000 years, a paper by Planetary Science Institute Research Scientist David Horvath says.

Oxygen is essential for the development of higher life. However, it was hardly present in the oceans of the young Earth. It was not until the evolution of photosynthetic bacteria that the oceans saw a significant increase in oxygen levels.

The Astrobiology Science Conference (AbSciCon) is a community-organized conference that provides a forum for reporting on new discoveries, sharing data and insights, advancing collaborative efforts and initiating new ones, planning new projects, and educating the next generation of astrobiologists.

Dust grains play a central role in the physics and chemistry of cosmic environments.

The 27 satellites of Uranus are enigmatic, with dark surfaces coated by material that could be rich in organics.

Massive and water-rich planets should be ubiquitous in the universe. Many of those worlds are expected to be subject to important irradiation from their host star, and display supercritical water layers surrounded by extended steam atmospheres.

Astronomers have identified more than 4,000, and counting, confirmed exoplanets -- planets orbiting stars other than the sun -- but only a fraction have the potential to sustain life.

The genome of single-celled plankton, known as dinoflagellates, is organized in an incredibly strange and unusual way, according to new research. The findings lay the groundwork for further investigation into these important marine organisms and dramatically expand our picture of what a eukaryotic genome can look like.

Lightning bolts break apart nitrogen and oxygen molecules in the atmosphere and create reactive chemicals that affect greenhouse gases.

The provenance of oxygen on Earth and other solar planetary bodies is a fundamental issue. It is widely accepted that the prebiotic pathway of oxygen production in the Earth primitive atmosphere was via vacuum ultraviolet (VUV) photodissociation of CO2 and subsequent recombination of two O atoms.

The discovery could be the "missing link" in the evolution of animals, according to the team, which included scientists from the U.S., United Kingdom, and Australia.

Polycyclic Aromatic Hydrocarbons (PAHs) have long been invoked in the study of interstellar and protostellar sources, but the unambiguous identification of any individual PAH has proven elusive until very recently.

This article deals with the most recent developments in the field of exoplanetary science connecting the interior of the planets with their habitability.