Archives

August 2021


An engineering lab at Dartmouth has been awarded two grants totaling $1.25 million to conduct planetary science research relating to the geophysics and astrobiology of icy planets in our solar system.

(Abridged) We characterize a series of neutral vanadium atomic absorption lines in the 800--910nm wavelength region of high signal-to-noise, high-resolution, telluric-corrected M-dwarf spectra from the CARMENES survey. Many of these lines are prominent and exhibit a distinctive broad and flat-bottom shape, which is a result of hyperfine structure (HFS).

Molecular oxygen, O2, is vital to life on Earth and possibly on other planets. Although the biogenic processes leading to its accumulation in Earth's atmosphere are well understood, its abiotic origin is still not fully established.

Central stages in the evolution of rocky, potentially habitable planets may play out under atmospheric conditions with a large inventory of non-dilute condensable components. Variations in condensate retention and accompanying changes in local lapse rate may substantially affect planetary climate and surface conditions, but there is currently no general theory to effectively describe such atmospheres.

Some researchers hypothesize that ice sheets enveloped the earth during the Marinoan glaciation (650-535 million years ago) in what is dubbed the "Snowball Earth."

New research has shed light on when plants first evolved the ability to respond to changing humidity in the air around them, and was probably a feature of a common ancestor of both flowering plants and ferns.

A new analysis of 2.5-billion-year-old rocks from Australia finds that volcanic eruptions may have stimulated population surges of marine microorganisms, creating the first puffs of oxygen into the atmosphere.

Titan, Saturn's largest moon, is a natural laboratory to study the origins of life. Like Earth, Titan has a dense atmosphere and seasonal weather cycles, but the chemical and mineralogical makeup are significantly different.

In the search for life elsewhere, astronomers have mostly looked for planets of a similar size, mass, temperature and atmospheric composition to Earth. However, astronomers from the University of Cambridge believe there are more promising possibilities out there.

We investigate a new class of habitable planets composed of water-rich interiors with massive oceans underlying H2-rich atmospheres, referred to here as Hycean worlds.

Plants will be a major component of advanced life support systems to enable deep space exploration that will take humans to the moon, Mars and beyond.

We have performed a search for flares and Quasi-Periodic Pulsations (QPPs) from low mass M dwarf stars using TESS 2 min cadence data.

Scientists at the University of Southampton have discovered that extensive chains of volcanoes have been responsible for both emitting and then removing atmospheric carbon dioxide (CO2) over geological time. This stabilised temperatures at Earth's surface.

In evolutionary biology, tracing back ancestral genetic elements is a quest in reconstructing the history of life on earth. The presence of similar or "homologous" genes in different species speaks of shared ancestry and of past molecular events that led to diversification from a common ancestor, ultimately leading to speciation.

In recent years, numerical models that were developed for Earth have been adapted to study exoplanetary climates to understand how the broad range of possible exoplanetary properties affects their climate state.

All-sky imaging surveys have identified several dozen isolated planetary-mass objects (IPMOs), far away from any star. Here, we examine the prospects for detecting transiting moons around these objects.

New analysis is presented of the 1.1 mm wavelength absorption lines in Venus' atmosphere that suggested the presence of phosphine.

The study of origins of life on Earth and the search for life on other planets are closely linked. Prebiotic chemical scenarios can help prioritize planets as targets for the search for life as we know it and can provide informative priors to help us assess the likelihood that particular spectroscopic features are evidence of life.

Understanding which genes are expressed in biological cells is key to understanding how biological organisms respond and adapt to the stresses of spaceflight.

Spaceflight is known to disrupt the immune system in astronauts. Previous research has also shown immune dysregulation in humans subjected to isolation on Earth.

Micro-organisms persisting deep below the seafloor for millions of years continue to evolve despite living at the energy limit to life.

It is speculated that there might be some linkage between interstellar aldehydes and their corresponding alcohols. Here, an observational study and astrochemical modeling are coupled together to illustrate the connection between them.

Pandora is a SmallSat mission designed to study the atmospheres of exoplanets, and was selected as part of NASA's Astrophysics Pioneers Program.

The history of life on Earth has often been likened to a four-billion-year-old torch relay. One flame, lit at the beginning of the chain, continues to pass on life in the same form all the way down. But what if life is better understood on the analogy of the eye, a convergent organ that evolved from independent origins? What if life evolved not just once, but multiple times independently?

Habitability has been generally defined as the capability of an environment to support life. Ecologists have been using Habitat Suitability Models (HSMs) for more than four decades to study the habitability of Earth from local to global scales.

Jupiter's clouds have water conditions that would allow Earth-like life to exist, but this isn't possible in Venus' clouds, according to the groundbreaking finding of new research led by a Queen's University Belfast scientist with participation of the University of Bonn. The study has been published in the journal Nature Astronomy.

We present the first determination of the abundance ratios of 13C substitutions of cyanoacetylene (HC3N), [H13CCCN]:[HC13CCN]:[HCC13CN] in Titan's atmosphere measured using millimeter-wave spectra obtained by the Atacama Large Millimeter-submillimeter Array.

Stellar systems are often formed through the collapse of dense molecular clouds which, in turn, return copious amounts of atomic and molecular material to the interstellar medium. An in-depth understanding of chemical evolution during this cyclic interaction between the stars and the interstellar medium is at the heart of astrochemistry.

Peptide bonds, as the molecular bridges that connect amino acids, are crucial to the formation of proteins. Searches and studies of molecules with embedded peptide-like bonds are thus important for the understanding of protein formation in space.

Among our solar system's many moons, Saturn's Titan stands out - it's the only moon with a substantial atmosphere and liquid on the surface. It even has a weather system like Earth's, though it rains methane instead of water. Might it also host some kind of life?

Exoplanets that receive stellar irradiance of approximately Earth's or less have been discovered and many are suitable for spectral characterization.

Perhaps the most fundamental puzzle in biology - "What is life?" - is addressed in a new paper by Planetary Science Institute Senior Scientist Oleg Abramov.

Cloud is critical for planetary climate and habitability, but it is also one of the most challenging parts of studying planets in and beyond the solar system. Previous simulations using global general circulation models (GCMs) found that for 1:1 tidally locked (i.e., synchronously rotating) terrestrial planets with oceans, strong convergence and convection produce optically thick clouds over the substellar area.

The advent of a new generation of radial velocity instruments has allowed us to break the one Earth-mass barrier. We report a new milestone in this context with the detection of the lowest-mass planet measured so far using radial velocities: L 98-59 b, a rocky planet with half the mass of Venus.

Nitrogen is vital for all forms of life¬: It is part of proteins, nucleic acids and other cell structures. Thus, it was of great importance for the development of life on early Earth to be able to convert gaseous dinitrogen from the atmosphere into a bio-available form - ammonium.

Take a closer look at the complex choreography involved in building NASA's Europa Clipper as the mission to explore Jupiter's moon Europa approaches its 2024 launch date.

Superflares, extreme radiation bursts from stars, have been suspected of causing lasting damage to the atmospheres and thus habitability of exoplanets. A newly published study found evidence that they only pose a limited danger to planetary systems, since the radiation bursts do not explode in the direction of the exoplanets.

A team of astronomers have used the European Southern Observatory's Very Large Telescope (ESO's VLT) in Chile to shed new light on planets around a nearby star, L 98-59, that resemble those in the inner Solar System. Amongst the findings are a planet with half the mass of Venus -- the lightest exoplanet ever to be measured using the radial velocity technique -- an ocean world, and a possible planet in the habitable zone.

One of the clearest but unresolved questions for Europa is the thickness of its icy shell. Europa's surface is resplendent with geological features that bear on this question, and ultimately on its interior, geological history, and astrobiological potential.

New research may provide a breakthrough for scientists to understand life in the harshest of environments.

Two hundred fifty-two million years ago, much of life on planet Earth was dying. In an event that marked the end of the Permian period, more than 96 percent of the planet's marine species and 70 percent of its terrestrial life suddenly went extinct. It was the largest extinction in Earth's history.

Microbial Tracking-3 (MT-3) is a NASA Space Biology investigation cataloging and characterizing potential disease-causing microorganisms aboard the International Space Station (ISS).

Virtually all oxygen on Earth was and is produced by photosynthesis, which was invented by tiny organisms, the cyanobacteria, when our planet was still a rather uninhabitable place.

New research led by the University of Bristol demonstrates that a decline in the concentration of atmospheric CO2 played a major role in driving Earth's climate from a warm greenhouse into a cold icehouse world around 34 million years ago. This transition could be partly reversed in the next centuries due to the anthropogenic rise in CO2.

Radio frequency interference (RFI) mitigation remains a major challenge in the search for radio technosignatures. Typical mitigation strategies include a direction-of-origin (DoO) filter, where a signal is classified as RFI if it is detected in multiple directions on the sky.

On July 13, 2021, the Cell Science-04 (CS-04) mission's first science operation was successfully conducted onboard the ISS. The on-orbit activities included setup of the Life Sciences Glovebox and the injection of tardigrades into the flow paths of the Bioculture System research platform.

A recent study led by the Cooperative Institute for Research in the Atmosphere (CIRA), a NOAA partner located at Colorado State University in Ft. Collins. Co., found that satellites from NOAA's Joint Polar Satellite System (JPSS) can detect a fascinating nocturnal phenomenon called "milky seas" from their perch about 500 miles up.

Pioneering research has revealed the erosion of ancient sediments found deep beneath Antarctic ice could be a vital and previously unknown source of nutrients and energy for abundant microbial life.

Two asteroids (203 Pompeja and 269 Justitia) have been discovered with a redder spectrum (※1) than any other object in the asteroid belt between Mars and Jupiter.

Spatial heterogeneity and temporal variability are general features in planetary weather and climate, due to the effects of planetary rotation, uneven stellar flux distribution, fluid motion instability, etc.