Archives

July 2021


The runaway greenhouse represents the ultimate climate catastrophe for rocky, Earth-like worlds: when the incoming stellar flux cannot be balanced by radiation to space, the oceans evaporate and exacerbate heating, turning the planet into a hot wasteland with a steam atmosphere overlying a possibly molten magma surface.

Upcoming NASA astrophysics missions such as the James Webb Space Telescope will search for signs of life on planets transiting nearby stars. Doing so will require co-adding dozens of transmission spectra to build up sufficient signal to noise while simultaneously accounting for challenging systematic effects such as surface/weather variability, atmospheric refraction, and stellar activity.

The impactor believed to have wiped out the dinosaurs and other life forms on Earth some 66 million years ago likely came from the outer half of the main asteroid belt, a region previously thought to produce few impactors.

A combination of a once-debunked 19th-century identification of a water-carrying iron mineral and the fact that these rocks are extremely common on Earth, suggests the existence of a substantial water reservoir on Mars, according to a team of geoscientists.

We predict that cyanoacetylene (HC3N) is produced photochemically in the atmosphere of GJ 1132 b in abundances detectable by the James Webb Space Telescope (JWST), assuming that the atmosphere is as described by Swain et al. (2021).

Researchers from The Hong Kong University of Science and Technology (HKUST) have decoded the chromosomal-level genome of a deep-sea gutless tubeworm and the genome of its co-living "partner" - a kind of bacteria that provide nutrients they generate from inorganic compounds to the worm for the first time, explaining how the pair adapts to the extreme habitat.

The Keck Planet Imager and Characterizer (KPIC) is a purpose-built instrument to demonstrate new technological and instrumental concepts initially developed for the exoplanet direct imaging field.

International drilling efforts over the last decades into the seafloor have provided increasing evidence for the existence of an extensive deep biosphere below the seafloor.

Ammonia (NH3) in a terrestrial planet atmosphere is generally a good biosignature gas, primarily because terrestrial planets have no significant known abiotic NH3 source.

Carbonaceous chondrite meteorites are so far the only available samples representing carbon-rich asteroids and in order to allow future comparison with samples returned by missions such as Hayabusa 2 and OSIRIS-Rex, is important to understand their physical properties.

While Earth may have been a habitable planet long before the Paleoarchean Era [3.6 to 3.2 billion years ago (Ga)], as rocks of this age retain a diversity of fossil evidence for life the complexity of life's cellular constituents, range of metabolic pathways, the niches it occupied locally, and global diversity of its habitats remain largely unknown.

For the first time, astronomers have uncovered evidence of water vapor in the atmosphere of Jupiter's moon Ganymede. This water vapor forms when ice from the moon's surface sublimates -- that is, turns from solid to gas.

U.S. National Science Foundation-funded researchers have discovered ethane-degrading microbes at hydrothermal vents in the Gulf of California's Guaymas Basin at a water depth of 2,000 meters. The results are published in the journal Science.

A simulation tool which utilizes parallel processing is developed to describe molecular kinetics in 2D, single-and multi-component atmospheres on Callisto.

A new analysis of data from ESA's Mars Express mission has revealed that our knowledge of the way these atmospheric gases interact with each other is incomplete.

The plant biology experiments of two NC State researchers are back on Earth after spending weeks at the International Space Station.

Ours could realistically be the generation to discover evidence of life beyond Earth. With this privileged potential comes responsibility. The magnitude of the question, "are we alone?", and the public interest therein, opens the possibility that results may be taken to imply more than the observations support, or than the observers intend.

The Alum Shale of Northern Europe not only has an eventful history of formation, connected with the microcontinent Baltica, it also holds great potential as an object of investigation for future research questions.

A team at the Natural History Museum (NHM), London is paving the way for future rovers to search for meteorites on Mars. The scientists are using the NHM's extensive meteorite collection to test the spectral instruments destined for the ExoMars rover Rosalind Franklin, and develop tools to identify meteorites on the surface of the red planet.

Scientists who study glacier ice have found viruses nearly 15,000 years old in two ice samples taken from the Tibetan Plateau in China. Most of those viruses, which survived because they had remained frozen, are unlike any viruses that have been cataloged to date.

The search for extraterrestrial intelligence (SETI) is a scientific endeavor which struggles with unique issues -- a strong indeterminacy in what data to look for and when to do so.

Searching for biomarkers on Mars is a primary goal of the ExoMars Trace Gas Orbiter.

NASA's Mars 2020 Perseverance rover has begun its search for signs of ancient life on the Red Planet.

Context. The molecular composition of interstellar ice mantles is defined by gas-grain processes in molecular clouds, with the main components being H2O, CO, and CO2. CH3OH ice is detected towards the denser regions, where large amounts of CO freeze out and get hydrogenated.

We report the first identification in space of H2NC, a high-energy isomer of H2CN that has been largely ignored in chemical and astrochemical studies. The observation of various unidentified lines around 72.2 GHz in the cold dark cloud L483 motivated the search for, and successful detection of, additional groups of lines in harmonic relation.

In the spirit of Trimble's ``Astrophysics in XXXX'' series, I very briefly and subjectively review developments in SETI in 2020. My primary focus is 74 papers and books published or made public in 2020, which I sort into six broad categories: results from actual searches, new search methods and instrumentation, target and frequency seleciton, the development of technosignatures, theory of ETIs, and social aspects of SETI.

The discovery of a large number of terrestrial exoplanets in the habitable zones of their stars, many of which are qualitatively different from Earth, has led to a growing need for fast and flexible 3D climate models, which could model such planets and explore multiple possible climate states and surface conditions.

In the search for life in the cosmos, transiting exoplanets are currently our best targets. In the search for life in the cosmos, transiting exoplanets are currently our best targets. With thousands already detected, our search is entering a new era of discovery with upcoming large telescopes that will look for signs of life in the atmospheres of transiting worlds.

The arrival of plants on land about 400 million years ago may have changed the way the Earth naturally regulates its own climate, according to a new study led by researchers at UCL and Yale.

As a guide for astronomers new to the field of technosignature search (i.e. SETI), I present an overview of some of its observational and theoretical approaches.

Surprisingly strong CO emission has been observed from more than a dozen debris disks around nearby main-sequence stars. The origin of this CO is unclear, in particular whether it is left over from the protoplanetary disk phase or is second-generation material released from collisions between icy bodies like debris dust.

An international team of astronomers have become the first in the world to detect isotopes in the atmosphere of an exoplanet.

According to clues left by the Cassini mission, Titan, one of the two Solar System bodies with a hydrologic cycle, may harbor liquid hydrocarbon-based analogs of our terrestrial aquifers, referred to as "alkanofers". On the Earth, petroleum and natural gas reservoirs show a vertical gradient in chemical composition, established over geological timescales.

Jupiter's moon Europa and its global ocean may currently have conditions suitable for life. Scientists are studying processes on the icy surface as they prepare to explore.

Many exoplanets have opaque atmospheres, obscured by clouds or hazes that make it hard for astronomers to characterize their chemical compositions. A new study shows that haze particles produced under different conditions have a wide range of properties that can determine how clear or hazy a planet's atmosphere is likely to be.

Dear Astrobiologists, NASA has released a Request for Information (RFI) related to the newly announced "Mission Equity," soliciting input from the public on topics of diversity, equity, and inclusion

The yeast C. albicans is a common opportunistic fungal pathogen responsible for a variety of superficial infections as well as systemic and more severe infections in humans.

Tidal stresses may be causing constant icequakes on Saturn's sixth largest moon Enceladus, a world of interest in the search for life beyond Earth, according to a new study.

Scientists know that the Earth was bombarded by huge impactors in distant time, but a new analysis suggest that the number of these impacts may have been x10 higher than previously thought.

Planets which are tilted on their axis, like Earth, are more capable of evolving complex life. This finding will help scientists refine the search for more advanced life on exoplanets. This NASA-funded research is presented at the Goldschmidt Geochemistry Conference.

Scientists at the University of Southampton have discovered that changes in Earth's orbit may have allowed complex life to emerge and thrive during the most hostile climate episode the planet has ever experienced.

Laboratory experiments play a key role in deciphering the chemistry of the interstellar medium (ISM) and the role that product complex organic molecules (COMs) may play in the origins of life.

In 2019, Reyes & Wright used the NASA Astrophysics Data System (ADS) to initiate a comprehensive bibliography for SETI accessible to the public.

A unique study of ancient diamonds has shown that the basic chemical composition of the Earth's atmosphere which makes it suitable for life's explosion of diversity was laid down at least 2.7 billion years ago.

In 2011, scientists confirmed a suspicion: There was a split in the local cosmos. Samples of the solar wind brought back to Earth by the Genesis mission definitively determined oxygen isotopes in the sun differ from those found on Earth, the moon and the other planets and satellites in the solar system.

An unknown methane-producing process is likely at work in the hidden ocean beneath the icy shell of Saturn's moon Enceladus, suggests a new study published in Nature Astronomy by scientists at the University of Arizona and Paris Sciences & Lettres University.

For most organisms, the stresses associated with spaceflight cause a variety of detrimental health effects. To foster a safe and productive long-term human presence in space, therapies and countermeasures to spaceflight-induced stress need to be developed. Tardigrades (water bears) are evolved to tolerate multiple extreme environments (polyextremophiles) restrictive to most life.

In this article a new, multi-functional, high-vacuum astrophysical ice setup, VIZSLA (Versatile Ice Zigzag Sublimation Setup for Laboratory Astrochemistry), is introduced. The instrument allows the investigation of astrophysical processes both in a low-temperature para-H2 matrix and in astrophysical analog ices.

ExoFit trials are field campaigns financed by ESA to test the Rosalind Franklin rover and to enhance collaboration practices between ExoMars working groups. During the first trial, a replicate of the ExoMars rover was remotely operated from Oxfordshire (United Kingdom) to perform a complex sequence of scientific operation at the Tabernas Desert (Spain).

The National Academy of Sciences Decadal Survey on Biological and Physical Sciences Research in Space 2023-2032 will review the state of knowledge in the current and emerging areas of space-related biological and physical sciences research and generate consensus recommendations for a comprehensive vision and strategy for a decade of transformative science at the frontiers of biological and physical sciences research in space.