1) Laboratory experiments found that amino acids like glycine, alanine, and serine can naturally form from the ultraviolet photolysis of interstellar ice analogs.
2) These amino acids would have a deuterium excess similar to what is seen in interstellar clouds, matching what is found in meteorites.
3) The formation of amino acids from interstellar ice photochemistry provides an explanation for the origin and deuterium enrichment of meteoritic organic molecules that is difficult to explain from their formation in liquid water on meteorite parent bodies.
This document summarizes research on uranium in Moroccan sedimentary rocks. It presents work on:
1) Optimizing analysis methods for uranium, thorium, radium and their descendants in samples.
2) Characterizing phases that concentrate radioisotopes.
3) Applying methods to study sedimentary deposits and separate particle sizes.
4) Studying distribution of natural radionuclides in solid phases like phosphates.
5) Extracting uranium and heavy metals from phosphates, oil shales, clays and more.
This document summarizes a study that investigated chromium-citrate and ferric-citrate complexes in aqueous solutions through potentiometric titration experiments. Specifically:
- Potentiometric titration curves showed inflection points, indicating the presence of dominant species for the Cr3+-citrate system. Analysis of the curves suggests the dominant species is a dimeric Cr3+-citrate complex.
- Speciation diagrams for the free citrate ligand agree with literature values. Ferric-citrate and Cr3+-citrate stability constants from literature also support dimer formation.
- The iron-citrate and chromium-citrate systems behaved similarly, both favoring dimeric metal-citrate complexes
This article discusses how methanol (MeOH) affects ascorbate (AsA) levels and related gene expression in Oncidium orchids. The study found that a low concentration of MeOH (50 mM) triggered hydrogen peroxide (H2O2) production and increased expression of AsA biosynthesis genes. However, a high MeOH concentration was toxic and depleted AsA levels. The increased gene expression from low MeOH levels was blocked by inhibitors of alcohol oxidase and NADPH oxidase, suggesting H2O2 is a signaling molecule regulating AsA gene expression in response to MeOH. The results help explain the mechanism by which MeOH stimulates AsA production in Oncidium at the molecular level.
Adsorption characteristics of a cationic porphyrin on nanoclay at various pHZachary Rice
- The document analyzes the adsorption behavior of a cationic porphyrin molecule (TMAP) onto montmorillonite clay at various pH levels using buffers.
- Spectroscopic analysis showed TMAP adsorbed to the clay in a monolayer at low and high pH, while slightly acidic/neutral pH caused it to possibly rearrange or form aggregates on the surface.
- Absorption spectra of TMAP on clay exhibited red shifts compared to free TMAP in solution, indicating flattening and electron delocalization of the porphyrin rings when adsorbed.
This document summarizes the synthesis and characterization of the oxomolybdenum mono-ene-1,2-dithiolate complex (Tp*)MoO(bdtCl2) (3). X-ray crystallography showed compound 3 crystallizes in the monoclinic space group P21/c, with a distorted octahedral coordination geometry around the Mo atom. IR, EPR, and electronic absorption spectroscopy indicate the chlorine substituents do not significantly perturb the electronic structure of the Mo(V) center, but solution redox potentials and gas-phase ionization energies are sensitive to remote substituent effects. The coordination environment of 3 is similar to the related complex (Tp*)MoO(
The document summarizes key information about organic molecules and cell membranes. It states that organic molecules contain carbon and are made up of polymers like carbohydrates, lipids, proteins, and nucleic acids, which are composed of monomers. The cell membrane forms the boundary between intra- and extracellular fluids using a phospholipid bilayer. It contains integral and peripheral proteins and transports molecules through channel and carrier proteins.
The document summarizes key information about organic molecules and cell membranes. It states that organic molecules contain carbon and are made up of polymers like carbohydrates, lipids, proteins, and nucleic acids, which are composed of monomers. The cell membrane forms the boundary between intracellular and extracellular fluids using a phospholipid bilayer. It contains integral and peripheral proteins and transports molecules through channel and carrier proteins.
The document summarizes key information about organic molecules and cell membranes. It states that organic molecules contain carbon and are made up of polymers like carbohydrates, lipids, proteins, and nucleic acids, which are composed of monomers. The cell membrane forms the boundary between intracellular and extracellular fluids using a phospholipid bilayer. It contains integral and peripheral proteins and transports molecules through channel and carrier proteins.
This document summarizes research on uranium in Moroccan sedimentary rocks. It presents work on:
1) Optimizing analysis methods for uranium, thorium, radium and their descendants in samples.
2) Characterizing phases that concentrate radioisotopes.
3) Applying methods to study sedimentary deposits and separate particle sizes.
4) Studying distribution of natural radionuclides in solid phases like phosphates.
5) Extracting uranium and heavy metals from phosphates, oil shales, clays and more.
This document summarizes a study that investigated chromium-citrate and ferric-citrate complexes in aqueous solutions through potentiometric titration experiments. Specifically:
- Potentiometric titration curves showed inflection points, indicating the presence of dominant species for the Cr3+-citrate system. Analysis of the curves suggests the dominant species is a dimeric Cr3+-citrate complex.
- Speciation diagrams for the free citrate ligand agree with literature values. Ferric-citrate and Cr3+-citrate stability constants from literature also support dimer formation.
- The iron-citrate and chromium-citrate systems behaved similarly, both favoring dimeric metal-citrate complexes
This article discusses how methanol (MeOH) affects ascorbate (AsA) levels and related gene expression in Oncidium orchids. The study found that a low concentration of MeOH (50 mM) triggered hydrogen peroxide (H2O2) production and increased expression of AsA biosynthesis genes. However, a high MeOH concentration was toxic and depleted AsA levels. The increased gene expression from low MeOH levels was blocked by inhibitors of alcohol oxidase and NADPH oxidase, suggesting H2O2 is a signaling molecule regulating AsA gene expression in response to MeOH. The results help explain the mechanism by which MeOH stimulates AsA production in Oncidium at the molecular level.
Adsorption characteristics of a cationic porphyrin on nanoclay at various pHZachary Rice
- The document analyzes the adsorption behavior of a cationic porphyrin molecule (TMAP) onto montmorillonite clay at various pH levels using buffers.
- Spectroscopic analysis showed TMAP adsorbed to the clay in a monolayer at low and high pH, while slightly acidic/neutral pH caused it to possibly rearrange or form aggregates on the surface.
- Absorption spectra of TMAP on clay exhibited red shifts compared to free TMAP in solution, indicating flattening and electron delocalization of the porphyrin rings when adsorbed.
This document summarizes the synthesis and characterization of the oxomolybdenum mono-ene-1,2-dithiolate complex (Tp*)MoO(bdtCl2) (3). X-ray crystallography showed compound 3 crystallizes in the monoclinic space group P21/c, with a distorted octahedral coordination geometry around the Mo atom. IR, EPR, and electronic absorption spectroscopy indicate the chlorine substituents do not significantly perturb the electronic structure of the Mo(V) center, but solution redox potentials and gas-phase ionization energies are sensitive to remote substituent effects. The coordination environment of 3 is similar to the related complex (Tp*)MoO(
The document summarizes key information about organic molecules and cell membranes. It states that organic molecules contain carbon and are made up of polymers like carbohydrates, lipids, proteins, and nucleic acids, which are composed of monomers. The cell membrane forms the boundary between intra- and extracellular fluids using a phospholipid bilayer. It contains integral and peripheral proteins and transports molecules through channel and carrier proteins.
The document summarizes key information about organic molecules and cell membranes. It states that organic molecules contain carbon and are made up of polymers like carbohydrates, lipids, proteins, and nucleic acids, which are composed of monomers. The cell membrane forms the boundary between intracellular and extracellular fluids using a phospholipid bilayer. It contains integral and peripheral proteins and transports molecules through channel and carrier proteins.
The document summarizes key information about organic molecules and cell membranes. It states that organic molecules contain carbon and are made up of polymers like carbohydrates, lipids, proteins, and nucleic acids, which are composed of monomers. The cell membrane forms the boundary between intracellular and extracellular fluids using a phospholipid bilayer. It contains integral and peripheral proteins and transports molecules through channel and carrier proteins.
Structural analysis of the valles marineris fault zone possible evidence for ...Carlos Bella
This study analyzes satellite images of the Ius and Coprates Chasmata regions in southern Valles Marineris on Mars to better understand the tectonic origin and evolution of this canyon system. Structural mapping revealed evidence for left-lateral strike-slip faulting, including en echelon folds, bookshelf faults, and thrusts. The total estimated left-lateral slip across the Valles Marineris fault zone is 150-160 km. This large strike-slip system on Mars suggests tectonic processes similar to plate tectonics have influenced crustal deformation, challenging previous hypotheses that the canyon formed through other mechanisms like rifting or subsurface material removal.
Variability of solar eruptions during cycle 23Carlos Bella
This document analyzes solar eruptions during solar cycle 23 from 1996-2001 using data from the SOHO mission. It finds that both the rate of coronal mass ejections (CMEs) and their average and median speeds increased from solar minimum to maximum. The CME rate increased by a factor of 10, while speeds increased by a factor of 2. There was also a poor correlation found between metric and DH type II radio bursts, attributed to different Alfven speeds in their source regions.
Vapor saturation of sodium: Key to unlocking the origin of chondrulesCarlos Bella
Sodium saturation of chondrules at their liquidus temperatures implies that vapor-condensed phase equilibrium was reached for elements more refractory than sodium during chondrule formation. Equilibrium calculations were performed on droplets from impacts on two target compositions to investigate conditions leading to sodium saturation. Droplets that retained 50% or 90% of their sodium at the liquidus closely resembled Type II chondrules under extreme dust enrichments or total pressures, suggesting chondrules formed in impact-generated plumes.
This document is the introduction to The Skeptic Encyclopedia of Pseudoscience. It provides an overview of the encyclopedia, which aims to objectively analyze prominent scientific and pseudoscientific claims. The introduction discusses the relationship between facts and theories in science. It notes that observations must be viewed through theoretical lenses, and references Darwin's view that observations are only useful if they are for or against some view. The introduction also discusses how views of science have changed over time between seeing it as progressively approaching truth, and as a relativistic social construct. It argues the field has moved to a more balanced middle view. The goal of the encyclopedia is to explore the borderlands where theory and data intersect, with the aim of achieving a
Offshore fresh groundwater reserves as a global phenomenonCarlos Bella
There is mounting evidence that vast reserves of fresh and brackish groundwater exist below continental shelves around the world. These offshore fresh groundwater reserves (OFGRs) were formed when sea levels were lower during glacial periods, exposing continental shelf areas that became recharged with precipitation and glacial meltwater. While some OFGRs may still be connected to modern coastal groundwater systems, many appear to be relics of past hydrological conditions and are termed "palaeo-groundwater". The largest documented OFGR is below the New Jersey shelf, where freshwater has been found over 100km offshore. Global occurrences of OFGRs have also been identified through borehole and geophysical data in locations such as the North
Revealing letters in rolled Herculaneum papyri by X-ray phase-contrast imagingCarlos Bella
X-ray phase-contrast tomography was used to read letters hidden inside two unopened Herculaneum papyri without damaging them. In a fragment of one papyrus, two Greek words were identified on a hidden layer. In an intact rolled papyrus, several letter sequences were revealed, including "APN", "HEY", and "KI". This non-destructive technique opens opportunities to read many rolled Herculaneum papyri and enhance knowledge of ancient Greek literature.
Cohesive forces prevent the rotational breakup of rubble-pile asteroid (29075...Carlos Bella
1) The asteroid (29075) 1950 DA is rotating faster than would be allowed without cohesive forces, with a rotation period of just over 2 hours.
2) Thermal infrared observations and measurements of its orbital drift were used to determine it has a low bulk density of 1.7 g/cm3, indicating it is a rubble pile asteroid made of smaller pieces held together weakly.
3) For it to retain its fine-grained surface and resist breaking up from centrifugal forces at its rate of rotation, cohesive van der Waals forces between the grains comparable to lunar regolith are required, with a minimum cohesive strength of 64 Pa.
Detection of Radio Emission from FireballsCarlos Bella
This document summarizes the detection of radio emissions from fireballs (very bright meteors) using the Long Wavelength Array radio telescope. A search of over 11,000 hours of all-sky radio images found 49 long-duration radio transients. Ten of these transients correlated spatially and temporally with fireballs detected by an optical meteor monitoring network. This provides evidence that fireballs emit previously undiscovered low frequency radio pulses. Further analysis found characteristics inconsistent with expected radio reflections from meteor trails, suggesting a non-thermal radio emission mechanism from the fireballs. This identifies a new class of natural radio transients and provides a new probe to study meteor physics.
Formation SiO2 Mass-Independent Oxygen Isotopic Partitioning During Gas-PhaseCarlos Bella
This document summarizes an experimental study that investigated oxygen isotopic partitioning during gas-phase silicon dioxide (SiO2) formation. The experiments involved laser ablation of silicon monoxide (SiO) in the presence of oxygen (O2) with and without hydrogen (H2). SiO2 formed in experiments without H2 showed normal mass-dependent isotopic fractionation, whereas those with H2 exhibited anomalous mass-independent fractionation. The extent of mass-independent fractionation in SiO2 increased with higher H2/O2 ratios. This provides the first experimental evidence that gas-to-particle conversion reactions can produce solids like SiO2 with oxygen isotopic compositions similar to early solar system materials like calcium-
High pre eruptive water contents preserved in lunar melt inclusionsSérgio Sacani
This study analyzed melt inclusions trapped in olivine crystals from lunar volcanic glass samples. The melt inclusions contained 615-1410 parts per million of water, much higher than previous measurements of lunar samples. They also contained high amounts of fluorine, sulfur, and chlorine similar to primitive terrestrial basalts. This indicates that some parts of the lunar interior contain as much water as Earth's upper mantle. The similarities to Earth and differences from previous models have implications for understanding the formation of the Earth-Moon system and the presence of water on the Moon.
High pre eruptive water contents preserved in lunar melt inclusionsSérgio Sacani
This study analyzed melt inclusions trapped in olivine crystals from lunar volcanic glass samples. The melt inclusions contained 615-1410 parts per million of water, much higher than previous measurements of lunar samples. They also contained high amounts of fluorine, sulfur, and chlorine similar to primitive terrestrial basalts. This indicates that parts of the lunar interior contain as much water as Earth's upper mantle, challenging theories that the Moon lost its entire volatile inventory during formation. The similarities between the lunar melt inclusions and terrestrial basalts suggest the lunar mantle source was similar in volatile content to Earth's upper mantle.
This article discusses findings from the MESSENGER spacecraft revealing details about Mercury's dynamic atmosphere. The spacecraft found that Mercury's polar regions contain large amounts of water ice, fulfilling predictions. However, measurements also surprisingly showed that the laser altimeter detected very low reflectance of Mercury's surface in polar regions, indicating it is coated in a dark, absorbing material in addition to water ice. Further studies are needed to understand the nature and origin of this dark material.
A possible carbonrich_interior_in_superearth_55_cancrieSérgio Sacani
1) The document analyzes the possibility that the interior of the super-Earth exoplanet 55 Cancri e could be carbon-rich rather than oxygen-rich.
2) Models that assume an oxygen-rich interior with iron, silicates, and a water envelope cannot fully explain 55 Cancri e's mass and radius measurements. However, a carbon-rich interior containing iron, silicon carbide, and/or carbon could explain the observations without needing a volatile envelope.
3) A carbon-rich interior for 55 Cancri e is plausible given the reported carbon-rich composition of its host star, though more data is needed on the star's elemental abundances and the planet's atmosphere.
Dark matter and the habitability of planetsSérgio Sacani
This document discusses how dark matter annihilation could provide an energy source to maintain surface temperatures suitable for liquid water on some planets, making them potentially habitable even without being orbiting a star. It explains that while dark matter annihilation provides negligible heating for Earth, larger planets in regions with higher dark matter densities like dwarf galaxies could capture and annihilate dark matter at rates sufficient to habitability through liquid water, with this heating lasting trillions of years for some planets. The document then examines dark matter capture in Earth and super-Earth planets and calculates surface temperatures on planets in environments with high dark matter densities.
1) The document describes an experiment where an ice mixture simulating interstellar medium composition was ultraviolet irradiated at 12K and analyzed after warming.
2) 16 amino acids were detected in the residue, including some that are also found in meteorites. Chiral amino acids showed enantiomeric separation.
3) The results demonstrate that amino acids can be spontaneously generated in interstellar ice analogs upon ultraviolet irradiation, supporting the hypothesis that amino acids could have been delivered to Earth by comets or meteorites.
The document summarizes key details about the 6 Apollo missions that landed astronauts on the Moon between 1969 and 1972. It provides facts such as two astronauts explored the lunar surface on each mission while a third orbited above in the command module. Samples collected by astronauts on the lunar surface proved extremely valuable for understanding the geological composition and history of the Moon. The document envisions future human exploration and utilization of lunar resources, including the establishment of a lunar base and extraction of oxygen and rocket propellants from lunar soils.
This summary provides the key points from the document in 3 sentences:
The document discusses evidence that some meteorites, including the Murchison meteorite, contain amino acids that preferentially exhibit left-handed chirality, suggesting life's preference for left-handed amino acids may have an extraterrestrial origin. While this finding is intriguing, it is difficult to definitively prove the excess is indigenous to the meteorites and not due to terrestrial contamination. New research on the Murchison meteorite helps address this issue by examining nitrogen isotope ratios of individual amino acid enantiomers, finding left-handed excesses that are too high to include much terrestrial material.
Animal behaviour: Incipient tradition in wild chimpanzeesCarlos Bella
This study observed the adoption of a new tool use behavior, moss sponging, by chimpanzees at the Sonso community in Uganda's Budongo Forest. The dominant male was first observed using a moss sponge to drink from a small flooded waterhole. Over the next six days, six other chimpanzees began displaying this behavior after observing the dominant male and female. The researchers used a statistical technique called network-based diffusion analysis to show the spread of this innovation was consistent with social learning along social network pathways, providing the first direct evidence of cultural diffusion in wild chimpanzees.
Preserved flora and organics in impact melt brecciasCarlos Bella
This document discusses the preservation of organic matter and plant remains in impact melt breccias found in Argentina. Analyses found centimeter-scale leaf fragments encapsulated in the impact glass that exhibited remarkable cellular-level preservation. Organic matter was also detected, including polycyclic aromatic hydrocarbons, alkanes, and pigment-like structures similar to chlorophyll. Heating experiments showed temperatures above 1500°C were required to preserve morphology, suggesting the impact process rapidly quenched and encapsulated the organic material. These findings demonstrate the potential for impact events to preserve biomarkers of early life on Mars.
A Sedna-like body with a perihelion of 80 astronomical unitsCarlos Bella
1) The document reports the discovery of 2012 VP113, the second known object after Sedna with an extremely distant perihelion of 80 AU, confirming that Sedna is not isolated.
2) Simulation results suggest there may be few inner Oort cloud objects with perihelia between 50-75 AU, and the population increases with perihelion distances greater than 75 AU.
3) Both Sedna and 2012 VP113 have similar arguments of perihelion, as do all other objects beyond 150 AU, suggesting they were perturbed by a possible unseen super-Earth mass perturber in the outer solar system that could restrict their arguments of perihelion.
Fuel gain exceeding unity in an inertially confined fusion implosionCarlos Bella
The document summarizes key results from experiments achieving fusion fuel gains exceeding unity using a "high-foot" laser pulse shape on the National Ignition Facility. Specifically:
1) Experiments achieved fusion fuel gains over unity for the first time, representing a 10x improvement over past experiments, and showed significant alpha heating and evidence of ignition requirements being met.
2) The "high-foot" pulse shape reduces instability during implosions by increasing ablation velocity and density scale length, improving stability compared to past "low-foot" experiments.
3) Improved performance is attributed to reduced mix from the ablator, with experiments pushing higher velocities through laser power and pattern optimization while maintaining hotspot shape control.
Structural analysis of the valles marineris fault zone possible evidence for ...Carlos Bella
This study analyzes satellite images of the Ius and Coprates Chasmata regions in southern Valles Marineris on Mars to better understand the tectonic origin and evolution of this canyon system. Structural mapping revealed evidence for left-lateral strike-slip faulting, including en echelon folds, bookshelf faults, and thrusts. The total estimated left-lateral slip across the Valles Marineris fault zone is 150-160 km. This large strike-slip system on Mars suggests tectonic processes similar to plate tectonics have influenced crustal deformation, challenging previous hypotheses that the canyon formed through other mechanisms like rifting or subsurface material removal.
Variability of solar eruptions during cycle 23Carlos Bella
This document analyzes solar eruptions during solar cycle 23 from 1996-2001 using data from the SOHO mission. It finds that both the rate of coronal mass ejections (CMEs) and their average and median speeds increased from solar minimum to maximum. The CME rate increased by a factor of 10, while speeds increased by a factor of 2. There was also a poor correlation found between metric and DH type II radio bursts, attributed to different Alfven speeds in their source regions.
Vapor saturation of sodium: Key to unlocking the origin of chondrulesCarlos Bella
Sodium saturation of chondrules at their liquidus temperatures implies that vapor-condensed phase equilibrium was reached for elements more refractory than sodium during chondrule formation. Equilibrium calculations were performed on droplets from impacts on two target compositions to investigate conditions leading to sodium saturation. Droplets that retained 50% or 90% of their sodium at the liquidus closely resembled Type II chondrules under extreme dust enrichments or total pressures, suggesting chondrules formed in impact-generated plumes.
This document is the introduction to The Skeptic Encyclopedia of Pseudoscience. It provides an overview of the encyclopedia, which aims to objectively analyze prominent scientific and pseudoscientific claims. The introduction discusses the relationship between facts and theories in science. It notes that observations must be viewed through theoretical lenses, and references Darwin's view that observations are only useful if they are for or against some view. The introduction also discusses how views of science have changed over time between seeing it as progressively approaching truth, and as a relativistic social construct. It argues the field has moved to a more balanced middle view. The goal of the encyclopedia is to explore the borderlands where theory and data intersect, with the aim of achieving a
Offshore fresh groundwater reserves as a global phenomenonCarlos Bella
There is mounting evidence that vast reserves of fresh and brackish groundwater exist below continental shelves around the world. These offshore fresh groundwater reserves (OFGRs) were formed when sea levels were lower during glacial periods, exposing continental shelf areas that became recharged with precipitation and glacial meltwater. While some OFGRs may still be connected to modern coastal groundwater systems, many appear to be relics of past hydrological conditions and are termed "palaeo-groundwater". The largest documented OFGR is below the New Jersey shelf, where freshwater has been found over 100km offshore. Global occurrences of OFGRs have also been identified through borehole and geophysical data in locations such as the North
Revealing letters in rolled Herculaneum papyri by X-ray phase-contrast imagingCarlos Bella
X-ray phase-contrast tomography was used to read letters hidden inside two unopened Herculaneum papyri without damaging them. In a fragment of one papyrus, two Greek words were identified on a hidden layer. In an intact rolled papyrus, several letter sequences were revealed, including "APN", "HEY", and "KI". This non-destructive technique opens opportunities to read many rolled Herculaneum papyri and enhance knowledge of ancient Greek literature.
Cohesive forces prevent the rotational breakup of rubble-pile asteroid (29075...Carlos Bella
1) The asteroid (29075) 1950 DA is rotating faster than would be allowed without cohesive forces, with a rotation period of just over 2 hours.
2) Thermal infrared observations and measurements of its orbital drift were used to determine it has a low bulk density of 1.7 g/cm3, indicating it is a rubble pile asteroid made of smaller pieces held together weakly.
3) For it to retain its fine-grained surface and resist breaking up from centrifugal forces at its rate of rotation, cohesive van der Waals forces between the grains comparable to lunar regolith are required, with a minimum cohesive strength of 64 Pa.
Detection of Radio Emission from FireballsCarlos Bella
This document summarizes the detection of radio emissions from fireballs (very bright meteors) using the Long Wavelength Array radio telescope. A search of over 11,000 hours of all-sky radio images found 49 long-duration radio transients. Ten of these transients correlated spatially and temporally with fireballs detected by an optical meteor monitoring network. This provides evidence that fireballs emit previously undiscovered low frequency radio pulses. Further analysis found characteristics inconsistent with expected radio reflections from meteor trails, suggesting a non-thermal radio emission mechanism from the fireballs. This identifies a new class of natural radio transients and provides a new probe to study meteor physics.
Formation SiO2 Mass-Independent Oxygen Isotopic Partitioning During Gas-PhaseCarlos Bella
This document summarizes an experimental study that investigated oxygen isotopic partitioning during gas-phase silicon dioxide (SiO2) formation. The experiments involved laser ablation of silicon monoxide (SiO) in the presence of oxygen (O2) with and without hydrogen (H2). SiO2 formed in experiments without H2 showed normal mass-dependent isotopic fractionation, whereas those with H2 exhibited anomalous mass-independent fractionation. The extent of mass-independent fractionation in SiO2 increased with higher H2/O2 ratios. This provides the first experimental evidence that gas-to-particle conversion reactions can produce solids like SiO2 with oxygen isotopic compositions similar to early solar system materials like calcium-
High pre eruptive water contents preserved in lunar melt inclusionsSérgio Sacani
This study analyzed melt inclusions trapped in olivine crystals from lunar volcanic glass samples. The melt inclusions contained 615-1410 parts per million of water, much higher than previous measurements of lunar samples. They also contained high amounts of fluorine, sulfur, and chlorine similar to primitive terrestrial basalts. This indicates that some parts of the lunar interior contain as much water as Earth's upper mantle. The similarities to Earth and differences from previous models have implications for understanding the formation of the Earth-Moon system and the presence of water on the Moon.
High pre eruptive water contents preserved in lunar melt inclusionsSérgio Sacani
This study analyzed melt inclusions trapped in olivine crystals from lunar volcanic glass samples. The melt inclusions contained 615-1410 parts per million of water, much higher than previous measurements of lunar samples. They also contained high amounts of fluorine, sulfur, and chlorine similar to primitive terrestrial basalts. This indicates that parts of the lunar interior contain as much water as Earth's upper mantle, challenging theories that the Moon lost its entire volatile inventory during formation. The similarities between the lunar melt inclusions and terrestrial basalts suggest the lunar mantle source was similar in volatile content to Earth's upper mantle.
This article discusses findings from the MESSENGER spacecraft revealing details about Mercury's dynamic atmosphere. The spacecraft found that Mercury's polar regions contain large amounts of water ice, fulfilling predictions. However, measurements also surprisingly showed that the laser altimeter detected very low reflectance of Mercury's surface in polar regions, indicating it is coated in a dark, absorbing material in addition to water ice. Further studies are needed to understand the nature and origin of this dark material.
A possible carbonrich_interior_in_superearth_55_cancrieSérgio Sacani
1) The document analyzes the possibility that the interior of the super-Earth exoplanet 55 Cancri e could be carbon-rich rather than oxygen-rich.
2) Models that assume an oxygen-rich interior with iron, silicates, and a water envelope cannot fully explain 55 Cancri e's mass and radius measurements. However, a carbon-rich interior containing iron, silicon carbide, and/or carbon could explain the observations without needing a volatile envelope.
3) A carbon-rich interior for 55 Cancri e is plausible given the reported carbon-rich composition of its host star, though more data is needed on the star's elemental abundances and the planet's atmosphere.
Dark matter and the habitability of planetsSérgio Sacani
This document discusses how dark matter annihilation could provide an energy source to maintain surface temperatures suitable for liquid water on some planets, making them potentially habitable even without being orbiting a star. It explains that while dark matter annihilation provides negligible heating for Earth, larger planets in regions with higher dark matter densities like dwarf galaxies could capture and annihilate dark matter at rates sufficient to habitability through liquid water, with this heating lasting trillions of years for some planets. The document then examines dark matter capture in Earth and super-Earth planets and calculates surface temperatures on planets in environments with high dark matter densities.
1) The document describes an experiment where an ice mixture simulating interstellar medium composition was ultraviolet irradiated at 12K and analyzed after warming.
2) 16 amino acids were detected in the residue, including some that are also found in meteorites. Chiral amino acids showed enantiomeric separation.
3) The results demonstrate that amino acids can be spontaneously generated in interstellar ice analogs upon ultraviolet irradiation, supporting the hypothesis that amino acids could have been delivered to Earth by comets or meteorites.
The document summarizes key details about the 6 Apollo missions that landed astronauts on the Moon between 1969 and 1972. It provides facts such as two astronauts explored the lunar surface on each mission while a third orbited above in the command module. Samples collected by astronauts on the lunar surface proved extremely valuable for understanding the geological composition and history of the Moon. The document envisions future human exploration and utilization of lunar resources, including the establishment of a lunar base and extraction of oxygen and rocket propellants from lunar soils.
This summary provides the key points from the document in 3 sentences:
The document discusses evidence that some meteorites, including the Murchison meteorite, contain amino acids that preferentially exhibit left-handed chirality, suggesting life's preference for left-handed amino acids may have an extraterrestrial origin. While this finding is intriguing, it is difficult to definitively prove the excess is indigenous to the meteorites and not due to terrestrial contamination. New research on the Murchison meteorite helps address this issue by examining nitrogen isotope ratios of individual amino acid enantiomers, finding left-handed excesses that are too high to include much terrestrial material.
Animal behaviour: Incipient tradition in wild chimpanzeesCarlos Bella
This study observed the adoption of a new tool use behavior, moss sponging, by chimpanzees at the Sonso community in Uganda's Budongo Forest. The dominant male was first observed using a moss sponge to drink from a small flooded waterhole. Over the next six days, six other chimpanzees began displaying this behavior after observing the dominant male and female. The researchers used a statistical technique called network-based diffusion analysis to show the spread of this innovation was consistent with social learning along social network pathways, providing the first direct evidence of cultural diffusion in wild chimpanzees.
Preserved flora and organics in impact melt brecciasCarlos Bella
This document discusses the preservation of organic matter and plant remains in impact melt breccias found in Argentina. Analyses found centimeter-scale leaf fragments encapsulated in the impact glass that exhibited remarkable cellular-level preservation. Organic matter was also detected, including polycyclic aromatic hydrocarbons, alkanes, and pigment-like structures similar to chlorophyll. Heating experiments showed temperatures above 1500°C were required to preserve morphology, suggesting the impact process rapidly quenched and encapsulated the organic material. These findings demonstrate the potential for impact events to preserve biomarkers of early life on Mars.
A Sedna-like body with a perihelion of 80 astronomical unitsCarlos Bella
1) The document reports the discovery of 2012 VP113, the second known object after Sedna with an extremely distant perihelion of 80 AU, confirming that Sedna is not isolated.
2) Simulation results suggest there may be few inner Oort cloud objects with perihelia between 50-75 AU, and the population increases with perihelion distances greater than 75 AU.
3) Both Sedna and 2012 VP113 have similar arguments of perihelion, as do all other objects beyond 150 AU, suggesting they were perturbed by a possible unseen super-Earth mass perturber in the outer solar system that could restrict their arguments of perihelion.
Fuel gain exceeding unity in an inertially confined fusion implosionCarlos Bella
The document summarizes key results from experiments achieving fusion fuel gains exceeding unity using a "high-foot" laser pulse shape on the National Ignition Facility. Specifically:
1) Experiments achieved fusion fuel gains over unity for the first time, representing a 10x improvement over past experiments, and showed significant alpha heating and evidence of ignition requirements being met.
2) The "high-foot" pulse shape reduces instability during implosions by increasing ablation velocity and density scale length, improving stability compared to past "low-foot" experiments.
3) Improved performance is attributed to reduced mix from the ablator, with experiments pushing higher velocities through laser power and pattern optimization while maintaining hotspot shape control.
This document summarizes meteor phenomena and bodies. It discusses the different types of interactions that can occur when meteoroids collide with Earth's atmosphere, including meteors, fireballs, bolides, explosive impacts, and meteoric dust particles. It also describes the various stages of a meteoroid's trajectory through the atmosphere, including orbital motion, preheating, ablation, dark flight, and impact. Finally, it provides an overview of the size ranges and velocities associated with different meteor phenomena.
The Origin Of The 1998 June BoöTid Meteor ShowerCarlos Bella
The document analyzes the origin of the 1998 June Boötid meteor shower through comparing orbital elements and simulating particle release from the potential parent comet 7P/Pons–Winnecke. It finds that:
1) 7P/Pons–Winnecke best matches the shower orbit based on the Tisserand invariant and D-discriminant.
2) Simulations show particles released from 7P/Pons–Winnecke in 1819 and 1869 were Earth-crossing in 1998 after Jovian perturbations altered their orbits starting in the 1940s.
3) This identifies 7P/Pons–Winnecke as the parent comet and 1819 and 1869 as the active returns
Physics first spectrum of ball lightningCarlos Bella
Researchers in China measured the first spectrum of ball lightning. They observed ball lightning form after a cloud-to-ground lightning strike about 900 meters away. The spectrum contained emission lines from silicon, iron, and calcium, elements common in soil. This supports the theory that ball lightning is formed when lightning vaporizes soil, producing glowing nanoparticles. It was about 2 meters wide and drifted horizontally for 30 meters before rising a few meters. This is the first direct observation of ball lightning forming from a lightning strike and the first measurement of its emission spectrum.
1) PSR J033711715 is a millisecond pulsar discovered to be in a hierarchical triple system with two white dwarf companions, making it the first known millisecond pulsar triple system.
2) Precise timing observations using multiple radio telescopes determined the masses of the pulsar (1.4378 solar masses), inner white dwarf companion (0.19751 solar masses), and outer white dwarf companion (0.4101 solar masses) to high precision.
3) The unexpectedly coplanar and nearly circular orbits of the system indicate an exotic evolutionary history and provide an opportunity to test theories of general relativity by studying the interactions between the bodies.
Transient Water Vapor at Europa’s South PoleCarlos Bella
1) Hubble Space Telescope images from November and December 2012 of Europa's atmosphere detected statistically significant surpluses of hydrogen Lyman-α and oxygen OI130.4 nm emissions above Europa's southern hemisphere in December 2012.
2) These emissions were observed in the same region over a period of ~7 hours, suggesting an inhomogeneous atmosphere, consistent with two 200-km-high plumes of water vapor with column densities of about 1020 m−2.
3) No plumes were detected in November 2012 images or previous 1999 images, indicating variable plume activity possibly related to Europa's changing orbital phases and surface stresses. The December 2012 plume was seen when Europa was near apocenter.
Solid-state plastic deformation in the dynamic interior of a differentiated a...Carlos Bella
This document summarizes a study that analyzed the microstructural properties of olivine grains in the diogenite meteorite Northwest Africa 5480 using electron backscatter diffraction techniques. The study found evidence of solid-state plastic deformation in the olivine-dominated zones, represented by a well-defined lattice-preferred orientation that is best explained by high-temperature deformation via the pencil-glide slip system, typically seen on Earth in dry ultramafic rocks deformed in the mantle. Numerical modeling indicates this observation in the meteorite can be explained by large-scale downwelling in the asteroid's mantle within the first 50 million years after formation, providing evidence of dynamic planet-like processes occurring in the interior of
Broadband high photoresponse from pure monolayer graphene photodetectorCarlos Bella
This document summarizes a research article that reports on the development of a high-performance photodetector using pure monolayer graphene. The researchers introduced electron trapping centers and created a bandgap in graphene through band structure engineering. This allowed them to achieve a high photoresponsivity of 8.61 A/W, about three orders of magnitude higher than previous graphene photodetectors. Additionally, they demonstrated broadband photoresponse from visible to mid-infrared wavelengths, the broadest reported for a pure graphene photodetector. By introducing defects and quantum confinement effects, they were able to greatly increase the lifetime of photo-generated carriers and achieve carrier multiplication, resulting in high photoresponsivity across a wide spectrum
A Complete Skull from Dmanisi, Georgia, and the Evolutionary Biology of Early...Carlos Bella
The article describes a newly discovered complete skull (D4500) from the site of Dmanisi, Georgia dating to 1.8 million years ago. It represents the earliest known completely preserved adult hominin skull. The skull possesses a small braincase of 546 cubic centimeters but also exhibits a large, prognathic face. This combination of features had not been seen before in the human fossil record. Analysis of this new skull and comparison to other remains from Dmanisi provides direct evidence of wide morphological variation within early members of the genus Homo, implying a single evolving lineage across continents.
Minor Planet Evidence for Water in the Rocky Debris of a Disrupted Extrasolar...Carlos Bella
Evidence has been found for water in the debris of a disrupted extrasolar minor planet orbiting a white dwarf star. Spectroscopic analysis of the white dwarf's atmosphere revealed an excess of oxygen that cannot be explained by oxide minerals alone, indicating the parent body was originally composed of about 26% water by mass. This demonstrates that water-bearing planetesimals can form around higher mass stars that eventually become white dwarfs. The disrupted planetesimal is the source of a circumstellar debris disk closely orbiting the white dwarf remnant.
Unique chemistry of a diamond-bearing pebble from the Libyan Desert Glass str...Carlos Bella
This document summarizes research on a unique black, shiny, and intensely fractured stone named "Hypatia" found in the Libyan Desert Glass strewnfield in southwest Egypt. Analysis showed the stone is composed primarily of amorphous carbonaceous matter containing nanodiamonds. Isotopic signatures of carbon and noble gases rule out a terrestrial origin and match cometary materials. The researchers propose Hypatia is a remnant of a comet nucleus fragment that was incorporated into the bolide that created the Libyan Desert Glass in an atmospheric airburst event 28.5 million years ago. Its shock transformation produced a weathering-resistant material that has been exceptionally preserved.
This document summarizes a heat-pipe model for early Earth's lithospheric dynamics and heat transport. Numerical simulations show that frequent volcanic eruptions could have advected surface materials downwards, developing a thick cold lithosphere. Declining heat sources over time would lead to an abrupt transition to plate tectonics. Evidence from the geologic record, such as rapid volcanic resurfacing and contractional deformation before 3.2 billion years ago, is consistent with predictions of the heat-pipe model. The model provides a framework for understanding Earth's evolution before the onset of plate tectonics.
Analysis of Surface Materials by Curiosity Mars Rover - Special CollectionCarlos Bella
Curiosity used its instruments to analyze materials along its traverse on Mars, yielding three key results:
1) It found a unique alkaline volcanic rock called "Jake_M" that is compositionally similar to rare mugearite rocks on Earth.
2) It analyzed windblown deposits and found two soil types - a common mafic type similar to global Martian soils, and a locally derived felsic type from broken down bedrock.
3) Chemical analysis of the soils found evidence of hydration in the amorphous soil components, suggesting absorbed water plays a role in Mars' global hydration signal detected from orbiters.
Adaptation of an Antarctic lichen to Martian niche conditions can occur withi...Carlos Bella
The study exposed the Antarctic lichen Pleopsidium chlorophanum to simulated Martian conditions in a Mars simulation chamber for 34 days to test its ability to adapt. Under conditions simulating the unprotected Martian surface, the fungal symbiont decreased metabolic activity and it was unclear if the algal symbiont was still photosynthesizing. However, under conditions simulating a protected niche environment, the entire lichen survived, remained photosynthetically active, and even increased its photosynthetic activity over the 34 days, demonstrating its ability to adapt to Martian conditions within a protected environment.
The internal energy and thermodynamic behaviour of a boson gas below the Bose...Carlos Bella
This document presents a new theory for the internal energy and thermodynamic behavior of an ideal boson gas below the Bose-Einstein temperature. The existing theory assumes particles lose kinetic energy when dropping into the ground state, leading to problems like infinite compressibility below TB. The new theory assumes particles retain their kinetic energy of 0.77kTB at TB. This yields expressions for internal energy and pressure below TB that are finite and agree with experiments. For liquid helium, the theory predicts a density maximum at 1.88K, close to the observed value of 2.18K.
Sequencing y chromosomes resolves discrepancy in time to common ancestor of m...Carlos Bella
The study sequenced the complete Y chromosomes of 69 males from diverse global populations. This identified over 11,000 genetic variants, resolving the phylogeny of male lineages. Applying molecular clock methods calibrated to the peopling of the Americas, the estimated time to the most recent common ancestor (TMRCA) of the Y chromosome was 120 to 156 thousand years, similar to estimates for the mitochondrial genome TMRCA of 99 to 148 thousand years. This challenges previous suggestions that male lineages coalesce more recently than female lineages.