Archives

March 2021


The habitable zone is the region around a star where standing bodies of liquid water can be stable on a planetary surface.

On Titan, methane (CH4) and ethane (C2H6) are the dominant species found in the lakes and seas.

A vast global ocean may have covered early Earth during the early Archean eon, 4 to 3.2 billion years ago, a side effect of having a hotter mantle than today, according to new research.

An evolutionary mystery that had eluded molecular biologists for decades may never have been solved if it weren't for the COVID-19 pandemic.

In the modern search for life elsewhere in the Universe, we are broadly looking for the following: the planets similar to Earth - physical indicators of habitability, and the manifestation of life - the biological signatures.

Research for possible biosignature gases on habitable exoplanet atmosphere is accelerating. We add isoprene, C5H8, to the roster of biosignature gases. We found that formation of isoprene geochemical formation is highly thermodynamically disfavored and has no known abiotic false positives.

When geobiology graduate student Katie Maloney trekked into the mountains of Canada's remote Yukon territory, she was hoping to find microscopic fossils of early life. Even with detailed field plans, the odds of finding just the right rocks were low. Far from leaving empty-handed, though, she hiked back out with some of the most significant fossils for the time period.

Mars today has no active volcanism and its atmosphere is oxidizing, dominated by the photochemistry of CO2 and H2O. Using a one-dimensional photochemical model, we consider whether plausible volcanic gas fluxes could have switched the redox-state of the past martian atmosphere to reducing conditions.

Researchers find that the earliest bacteria had the tools to perform a crucial step in photosynthesis, changing how we think life evolved on Earth.

We present observations of two bright M dwarfs (TOI-1634 and TOI-1685: J=9.5−9.6) hosting ultra-short period (USP) planet candidates, identified by the TESS mission.

We present one of the first Shanghai Tian Ma Radio Telescope (TMRT) K Band observations towards a sample of 26 infrared dark clouds (IRDCs).

In the quest for habitable planets beyond our own, NASA is studying a mission concept called Pandora, which could eventually help decode the atmospheric mysteries of distant worlds in our galaxy.

In Kevin Hand's "Alien Oceans: The Search For Life In The Depths Of Space" we learn that Earth is just one example of a myriad ways that a world can have an ocean. And searching for life on other ocean worlds requires a combination of old tools and new approaches to using those tools.

We live on an ocean world with 71% its surface covered by a water. For all of history humans had an intrinsic bias that all inhabited worlds would have large oceans - since we do. Indeed, the large flat plains of our Moon still bear names of imaginary seas based on that bias and early telescopes. That said we held to the notion that life would arise on a world if only it had Earth's basic characteristics - one of which was large bodies of water. Well, we now know that there is more than one way to have a planet with lots of liquid water.

Much of the carbon in space is believed to exist in the form of large molecules called polycyclic aromatic hydrocarbons (PAHs). Since the 1980s, circumstantial evidence has indicated that these molecules are abundant in space, but they have not been directly observed.

The NASA-funded Seismometer to Investigate Ice and Ocean Structure (SIIOS) performed well in seismic experiments conducted in snowy summer Greenland, according to a new study by the SIIOS team led by the University of Arizona published this week in Seismological Research Letters.

Scientists have discovered a vast, previously unknown reservoir of new aromatic material in a cold, dark molecular cloud by detecting individual polycyclic aromatic hydrocarbon molecules in the interstellar medium for the first time, and in doing so are beginning to answer a three-decades-old scientific mystery: how and where are these molecules formed in space?

All organisms exposed to the spaceflight environment exhibit changes in the expression of many genes relative to the comparable ground controls left on Earth. The Multi-Spectral Fluorescence Imaging System (Spectrum) enables scientists to monitor these changes in real time, non-destructively, using live organisms (plants, bacteria, fungi, small invertebrates).

CO2+H2 greenhouse warming has recently emerged as a promising scenario to sufficiently warm the early martian surface to allow the formation of valley networks and lakes.

Simple systems can reproduce faster than complex ones. So, how can the complexity of life have arisen from simple chemical beginnings?

Determining habitable zones in binary star systems can be a challenging task due to the combination of perturbed planetary orbits and varying stellar irradiation conditions.

The Earth's N2-dominated atmosphere is a very special feature. Firstly, N2 as main gas is unique on the terrestrial planets in the inner solar system and gives a hint for tectonic activity.

Direct imaging of exoplanets is usually limited by quasi-static speckles. These uncorrected aberrations in a star's point spread function (PSF) obscure faint companions and limit the sensitivity of high-contrast imaging instruments.

A starshade suppresses starlight by a factor of 1E11 in the image plane of a telescope, which is crucial for directly imaging Earth-like exoplanets.

Context: The long-term carbonate-silicate cycle plays an important role in the evolution of Earth's climate and, therefore, may also be an important mechanism in the evolution of the climates of Earth-like exoplanets.

Astrochemistry lies at the nexus of astronomy, chemistry, and molecular physics. On the basis of precise laboratory data, a rich collection of more than 200 familiar and exotic molecules have been identified in the interstellar medium, the vast majority by their unique rotational fingerprint.

The precise characterization of terrestrial atmospheres with the James Webb Space Telescope (JWST) is one of the utmost goals of exoplanet astronomy in the next decade.

One of the most profound discoveries in planetary science over the past 25 years is that worlds with oceans beneath layers of rock and ice are common in our solar system.

The new science results indicate that a large quantity of the Red Planet's water is trapped in its crust rather than having escaped into space.

In a comment published today in Nature Astronomy, Dr. Nathalie Cabrol, Director of the Carl Sagan Center for Research at the SETI Institute, challenges assumptions about the possibility of modern life on Mars held by many in the scientific community.

Lightning strikes were just as important as meteorites in creating the perfect conditions for life to emerge on Earth, geologists say. Minerals delivered to Earth in meteorites more than 4 billion years ago have long been advocated as key ingredients for the development of life on our planet.

An atmosphere is what makes life on Earth's surface possible, regulating our climate and sheltering us from damaging cosmic rays. But although telescopes have counted a growing number of rocky planets, scientists had thought most of their atmospheres long lost.

In order to withstand the rigors of space on deep-space missions, food grown outside of Earth needs a little extra help from bacteria. Now, a recent discovery aboard the International Space Station (ISS) has researchers may help create the 'fuel' to help plants withstand such stressful situations.

Data suggest that most rocky exoplanets with orbital period p < 100 d ("hot" rocky exoplanets) formed as gas-rich sub-Neptunes that subsequently lost most of their envelopes, but whether these rocky exoplanets still have atmospheres is unknown.

We humans just landed yet another rover on Mars. As has been the case for decades, each mission to Mars builds upon the successes and failures of those that preceded it. And each mission seeks to ask more profound questions that its predecessors. The Perseverance rover is now unpacking itself and preparing to explore Jezero crater - a mobile astrobiologist in search of evidence that Mars may have once harbored life.

How we got the point where we can send complex droids to Mars was not easy. It all started with people looking through telescopes - often with overactive imaginations. That led to spacecraft barely more sophisticated than a toaster with a shortwave radio which shattered many of those earlier preconceptions. Those early missions blazed a trail of ever increasing complexity and sophistication.

Large surveys with new-generation high-contrast imaging instruments are needed to derive the frequency and properties of exoplanet populations with separations from ∼5 to 300 AU.

We evaluate what will be the effectiveness of the ExoMars Raman Laser Spectrometer (RLS) to determine the degree of serpentinization of olivine-rich units on Mars.

Hydrocarbons such as methane and ethane are present in many solar system objects, including comets, moons and planets.

We present the compositional analysis of three terrestrial analogues of Martian olivine-bearing rocks derived from both laboratory and flight-derived analytical instruments.

We present the results of a study of the prospect of detecting habitable Trojan planets in the Kepler Habitable Zone circumbinary planetary systems (Kepler-16, -47, -453, -1647, -1661).

We seek to model the coupled evolution of a planet and a civilization through the era when energy harvesting by the civilization drives the planet into new and adverse climate states.

The weathering of silicate rocks plays an important role to keep the climate on Earth clement.

Reconciling the geology of Mars with models of atmospheric evolution remains a major challenge.

A researcher at the Instituto de Astrofísica de Canarias (IAC) is the lead author of a study with proposals for "technosignatures" -evidence for the use of technology or industrial activity in other parts of the Universe- for future NASA missions.

We report the detection of an atmosphere on a rocky exoplanet, GJ 1132 b, which is similar to Earth in terms of size and density.

According to a UC Riverside study, 555-million-year-old oceanic creatures from the Ediacaran period share genes with today's animals, including humans.

In this work, we present the analysis of 33,054 M-dwarf stars located within 100 parsecs in the Transiting Exoplanet Survey Satellite (TESS) Full Frame Images (FFIs) of the observed sectors 1 to 5.

Testing 3D hydrodynamic models of stellar atmospheres is feasible by retrieving spectral line shapes across stellar disks, using differential spectroscopy during exoplanet transits.

The Habitable zone Planet Finder (HPF) is a fiber fed precise radial velocity spectrograph at the 10 m Hobby Eberly Telescope (HET). Due to its fixed altitude design, the HET pupil changes appreciably across a track, leading to significant changes of the fiber far-field illumination.

In the search for small exoplanets orbiting cool stars whose spectral energy distributions peak in the near infrared, the strong absorption of radiation in this region due to water vapour in the atmosphere is a particularly adverse effect for the ground-based observations of cool stars.

The young (50-400 Myr) A3V star β Leo is a primary target to study the formation history and evolution of extrasolar planetary systems as one of the few stars with known hot (∼1600∘K), warm (∼600∘K), and cold (∼120∘K) dust belt components.

Measurements of visible and near-infrared reflection (0.38-5 um) and mid to far infrared emission (5-200 um) from telescope and satellite remote sensing instruments make it possible to investigate the composition of planetary surfaces via electronic transitions and vibrational modes of chemical bonds.

Spectroscopy of transiting exoplanets can be used to investigate their atmospheric properties and habitability.

The Atacama Desert has long been established as an excellent site for submillimeter observations. Yet identifying potentially optimal locations for a new facility within this region can require long field campaigns that rely on the construction of weather stations and radiometer facilities to take data over sufficiently long timescales.

In early 2016, an icy visitor from the edge of our solar system hurtled past Earth. It briefly became visible to stargazers as Comet Catalina before it slingshot past the Sun to disappear forevermore out of the solar system.

Tiny photonic devices could be used to find new exoplanets, monitor our health, and make the internet more energy efficient.

Earth's modern atmosphere is highly oxygenated and is a remotely detectable signal of its surface biosphere. However, the lifespan of oxygen-based biosignatures in Earth's atmosphere remains uncertain, particularly for the distant future.

We report the first detection of a hydroxyl radical (OH) emission signature in the planetary atmosphere outside the solar system, in this case, in the day-side of WASP-33b.

It is well-known that the chances of success of SETI depend on the longevity of technological civilizations or, more broadly, on the duration of the signs of their existence, or technosignatures.

During the past 25 years astronomers have discovered a wide variety of exoplanets, made of rock, ice and gas, thanks to the construction of astronomical instruments designed specifically for planet searches.

Extra Dwarf Pak Choi plants are pictured growing inside the Veggie space botany research facility aboard the International Space Station. The Veg-03 investigation is exploring how to grow food in space and assesses the impact of space gardening on crew morale and mood.

The tectonic regime of rocky planets fundamentally influences their long-term evolution and cycling of volatiles between interior and atmosphere. Earth is the only known planet with active plate tectonics, but observations of exoplanets may deliver insights into the diversity of tectonic regimes beyond the solar system.

A Ludwig-Maximilians-Universitaet (LMU) in Munich team has shown that slight alterations in transfer-RNA molecules (tRNAs) allow them to self-assemble into a functional unit that can replicate information exponentially. tRNAs are key elements in the evolution of early life-forms.

New and unique opportunities now exist to look for technosignatures (TS) beyond traditional SETI radio searches, motivated by tremendous advances in exoplanet science and observing capabilities in recent years.

Water (H2O), in all forms, is an important constituent in planetary bodies, controlling habitability and influencing geological activity.

When scientists complete an experiment aboard the International Space Station, the ramifications of that work have just begun. NASA carries on a legacy of decades of biological research data, fueling new discoveries long after studies wrap up in space.

We present the discovery in TMC-1 of allenyl acetylene, H2CCCHCCH, through the observation of nineteen lines with a signal-to-noise ratio ~4-15. For this species, we derived a rotational temperature of 7 +/- 1 K and a column density of (1.2 +/- 0.2)e13 cm-2.