Archives

October 2019


This textbook gives a perspective of heliophysics in a way that emphasizes universal processes from a perspective that draws attention to what provides Earth (and similar (exo-)planets) with a relatively stable setting in which life as we know it can thrive. The book is intended for students in physical sciences in later years of their university training and for beginning graduate students in fields of solar, stellar, (exo-)planetary, and planetary-system sciences.

An exoplanet may seem like the perfect spot to set up housekeeping, but before you go there, take a closer look at its star. Rice University astrophysicists are doing just that, building a computer model to help judge how a star's own atmosphere impacts its planets, for better or worse.

Researchers supported in part by the NASA Astrobiology Program have used genome-resolved metagenotics and metatranscriptomics to better understand microbial communities in the subseafloor near hydrothermal vents.

Multiple hypotheses/models have been put forward regarding the cooling history of the Earth. The search for life beyond Earth has brought these models into a new light as they connect to one of the two energy sources life can tap.

More than 4,000 planets are known that orbit stars other than our Sun. Many harbor a dynamic atmosphere that is cold enough that cloud particles can form in abundance. The diversity of exoplanets leads to differences in cloud coverage depending on global system parameters.

Phosphorus-bearing species are an essential key to form life on Earth, however they have barely been detected in the interstellar medium. Since only PN and PO have been identified so far towards star-forming regions, the chemical formation pathways of P-bearing molecules are not easy to constrain and are thus highly debatable.

After a very easy, uneventful flight south on the IL-76, we made it to the ice runway at Novolazarevskaya Tuesday afternoon.

Future space telescopes may be able to directly image ∼10 - 100 planets with sizes and orbits consistent with habitable surface conditions ("exo-Earth candidates" or EECs), but observers will face difficulty in distinguishing these from the potentially hundreds of non-habitable "false positives" which will also be detected.

To understand the role that planet formation history has on the observable atmospheric carbon-to-oxygen ratio (C/O) we have produced a population of astrochemically evolving protoplanetary disks.

Oxygen fugacity is a measure of rock oxidation that influences planetary structure and evolution. Most rocky bodies in the Solar System formed at oxygen fugacities approximately five orders of magnitude higher than a hydrogen-rich gas of solar composition.

We depart Cape Town in the IL-76 for Antarctica at 0900 local. We should be in Antarctica 6 hours later. Cheers, Dale

We present high spectral resolution optical spectra obtained with the ARCES instrument at Apache Point Observatory showing detection of the [OI]6300 A line in interstellar comet 2I/Borisov.

The Cassini/Composite InfraRed Spectrometer (CIRS) instrument has been observing the middle atmosphere of Titan over almost half a Saturnian year.

M dwarfs host most of the exoplanets in the local Milky Way. Some of these planets, ranging from sub-Earths to super-Jupiters, orbit in their stars' habitable zones, although many likely possess surface environments that preclude habitability.

Grain surfaces play a central role in the formation and desorption of molecules in space. To form molecules on a grain surface, adsorbed species trapped in binding sites must be mobile and migrate to adjacent sites.

Most researchers believe that the mass extinction 201 million years ago was caused by release of CO2 by volcanism with global warming as a consequence. Now, new data from fern spores suggest there might have been more to it than that.

A controversial theory that suggests an extraterrestrial body crashing to Earth almost 13,000 years ago caused the extinction of many large animals and a probable population decline in early humans is gaining traction from research sites around the world.

On Wednesday I hit the road and start making my way to Antarctica via Cape Town, South Africa. My team and I will arrive in Cape Town on Thursday, and weather and aircraft permitting, we will depart for the ice runway at Novolazarevskaya in Queen Maud Land on Tuesday the 29th.

This paper considers how planetesimal impacts affect planetary atmospheres.

A team of researchers led by Professor Ikawa Masahito from the Research Institute for Microbial Diseases of Osaka University, in a joint research project with the University of Tsukuba and the Japan Aerospace Exploration Agency, raised 12 male mice in the Japanese Experiment Module "Kibo" on the International Space Station for 35 days.

Subsequent to the Moon's formation, late accretion to the terrestrial planets modified their silicate crusts and mantles.

New research on an enzyme that is essential for photosynthesis and all life on earth has uncovered a key finding in its structure which reveals how light can interact with matter to make an essential pigment for life.

Though our understanding of the anatomy of the earliest animals is growing ever more precise, we know next to nothing about their behaviour.

Alpha Centauri A is the closest solar-type star to the Sun and offers an excellent opportunity to detect the thermal emission of a mature planet heated by its host star.

Viruses are non-living creatures, consisting of genetic material encased in a protein coat. Once the virus infects a living organism, it can replicate itself and continue on.

Chloroplasts in photosynthetic eukaryotes originated from a cyanobacterial endosymbiosis far more than 1 billion years ago 1-3. Due to this ancientness, it remains unclear how this evolutionary process proceeded.

Tardigrades, also known as water bears, are animals that can survive extreme conditions.

Correct estimates of stellar extreme ultraviolet (EUV; 100 - 1170 Å) flux are important for studying the photochemistry and stability of exoplanet atmospheres, as EUV radiation ionizes hydrogen and contributes to the heating, expansion, and potential escape of a planet's upper atmosphere.

Mars once had salt lakes that are similar to those on Earth and has gone through wet and dry periods, according to an international team of scientists that includes a Texas A&M University College of Geosciences researcher.

Fractured rocks of impact craters have been suggested to host deep microbial communities on Earth, and potentially other terrestrial planets, yet direct evidence remains elusive.

NASA released a report Friday with recommendations from the Planetary Protection Independent Review Board (PPIRB) the agency established in response to a recent National Academies of Sciences, Engineering, and Medicine report and a recommendation from the NASA Advisory Council. Full report: NASA Response to Planetary Protection Independent Review Board Recommendations

We investigate the possibility of finding Earth-like planets in the habitable zone of 34 nearby FGK-dwarfs, each known to host one giant planet exterior to their habitable zone detected by RV.

Volatile molecules are critical to habitability, yet difficult to observe directly at the optically thick midplanes of protoplanetary disks, where planets form.

We investigated the chemical evolution of HC3N in six dense molecular clouds, using archival available data from the Herschel infrared Galactic Plane Survey (Hi-GAL) and the Millimeter Astronomy Legacy Team Survey at 90 GHz (MALT90).

Sedimentary deposits characterized by the Mars Science Laboratory Curiosity rover provide evidence that Gale crater, Mars intermittently hosted a fluvio-lacustrine environment during the Hesperian.

NASA will host a media teleconference at 3:30 p.m. EDT Friday, Oct. 18, to discuss recommendations presented by the Planetary Protection Independent Review Board (PPIRB), established in June 2019 by Thomas Zurbuchen, associate administrator for the agency's Science Mission Directorate.

About 4000 exoplanets have been confirmed since the year of 1992, and for most of the planets, the main parameters that can be measured are planetary radius and mass.

Exporting terrestrial life out of the Solar System requires a process that both embeds microbes in boulders and ejects those boulders out of the Solar System.

Zeroth moment maps of some simple molecules, and selected transitions of COMs.

Terrestrial planets orbiting within the habitable zones of M-stars are likely to become tidally locked in a 1:1 spin:orbit configuration and are prime targets for future characterization efforts.

The energy balance and climate of planets can be affected by the reflective properties of their land, ocean, and frozen surfaces.

We explore here the prospects for detection of both giant circumbinary exoplanets, and brown dwarfs orbiting Galactic double white dwarfs binaries (DWDs) with the LISA mission.

We present an observational study of the sulfur (S)-bearing species towards Orion KL at 1.3 mm by combining ALMA and IRAM-30m single-dish data.

A long-term goal of exoplanet studies is the identification and detection of biosignature gases. Beyond the most discussed biosignature gas O2, only a handful of gases have been considered in detail.

Phosphorus is a key ingredient in terrestrial biochemistry, but is rarely observed in the molecular ISM and therefore little is known about how it is inherited during the star and planet formation sequence.

The investigation of star forming regions have enormously benefited from the recent advent of the ALMA interferometer.

The star EPIC 249706694 (HD 139139) was found to exhibit 28 transit-like events over an 87 day period during the Kepler mission's K2 Campaign 15 (Rappaport et al. 2019).

Effective deposition velocities in the converged atmosphere-ocean chemistry solutions. Solid lines are from the Sun-like star cases, and dashed lines are from the GJ 876 cases. The effective deposition velocities are self-consistently calculated, and are different from case to case.

Comets screaming through the atmosphere of early Earth at tens of thousands of miles per hour likely contained measurable amounts of protein-forming amino acids.

The increasing number of newly detected exoplanets at short orbital periods raises questions about their formation and migration histories.

Comet 21P/Giacobini-Zinner (hereafter, comet 21P/G-Z) is a Jupiter-family comet and a parent comet of the October Draconids meteor shower.

The habitable fraction of a planet's surface is important for the detectability of surface biosignatures.

The composition of comets in the solar system come in multiple groups thought to encode information about their formation in different regions o fthe outer protosolar disk.

The goal of this research is to study how the fragmentation of planetary embryos can affect the physical and dynamical properties of terrestrial planets around solar-type stars.

To truly understand how the body works and improve human health, researchers need to tease apart the building blocks of our cells. But as scientists continue to make major breakthroughs in cellular biology, an important question lingers: How did cells originally form billions of years ago?

If you could travel back in time 3.5 billion years, what would Mars look like? The picture is evolving among scientists working with NASA's Curiosity rover.

A new study of the Ovda Fluctus lava flow on Venus indicates that it is made of basaltic lava. This discovery weakens the notion that Venus might once have been Earth-like with an ancient ocean of liquid water.

Uncovering how the first biological molecules (like proteins and DNA) arose is a major goal for researchers attempting to solve the origin of life.

About 466 Mya, a major impact event took place between the orbits of Mars and Jupiter. Space dust spread all across the Solar System, and some of it was found near Saint-Petersburg, Russia, and in the south of Sweden.

Titan is unique in the solar system as it hosts a dense atmosphere mainly made of N2 and CH4. Cassini-Huygens revealed the presence of an intense atmospheric photochemistry initiated by the photo-dissociation and ionization of N2 and CH4.

A radio transmitter which is accelerating with a non-zero radial component with respect to a receiver will produce a signal that appears to change its frequency over time. This effect, commonly produced in astrophysical situations where orbital and rotational motions are ubiquitous, is called a drift rate.

In the science fiction film Interstellar, a band of intrepid astronauts sets out to explore a system of planets orbiting a supermassive black hole, searching for a world that may be conducive to hosting human life.

We study the effects of grain surface reactions on the chemistry of protoplanetary disks where gas, ice surface layers and icy mantles of dust grains are considered as three distinct phases.

New kinds of organic compounds, the ingredients of amino acids, have been detected in the plumes bursting from Saturn's moon Enceladus. The findings are the result of the ongoing deep dive into data from NASA's Cassini mission.

Diminutive animals known as tardigrades appear to us as plump, squeezable toys, earning them irresistible nicknames such as "water bears" and "moss piglets."

In situ exploration of the planetary atmospheres requires the development of laboratory experiments to understand the molecular growth pathways initiated by photochemistry in the upper layers of the atmospheres.

Two of TESS's major science goals are to measure masses for 50 planets smaller than 4 Earth radii and to discover high-quality targets for atmospheric characterization efforts.