. Scientific Frontline: Space Science
Showing posts with label Space Science. Show all posts
Showing posts with label Space Science. Show all posts

Wednesday, November 30, 2022

Small asteroids are probably young

Simulation of the SCI impact. a) – c) Snapshots of the simulation at different times. At t = 1200s, the development of the crater is over. d) SCI crater on the asteroid Ryugu. The key characteristics of the observed crater, including the displacement of the boulders, are recreated in the simulation.
Credit: Courtesy of Martin Jutzi

The impact experiment conducted on the asteroid Ryugu by the Japanese Hayabusa2 mission which took place two years ago resulted in an unexpectedly large crater. With the use of simulations, a team led by the University of Bern and the National Center of Competence in Research (NCCR) PlanetS has recently succeeded in gaining new insights from the experiment regarding the formation and development of asteroids. These insights are also important for the DART mission of NASA.

The Hayabusa2 spacecraft was developed in order to study the history of the asteroid Ryugu, and collected samples and returned them to earth for laboratory analysis. The project participants are Dr. Martin Jutzi and Dr. Sabina Raducan, both from the Physical Institute of the University of Bern, Department for Space Research and Planetology (WP), and are members of the National Center of Competence in Research (NCCR) PlanetS. Under their leadership, in a study which has recently been published in Nature Communications, the team has presented new findings on the formation and development of asteroids.

Monday, November 28, 2022

Rock Samples from the Floor of Jezero Crater Show Significant Contact with Water Together with Possible Organic Compounds

A photo of Jezero Crater on Mars. It was taken by instruments on NASA's Mars Reconnaissance Orbiter (MRO), which regularly takes images of potential landing sites for future missions.
Hi-Res Full-Size Image
Credit: NASA/JPL-Caltech/MSSS/JHU-APL

Analysis of multiple rocks found at the bottom of Jezero Crater on Mars, where the Perseverance rover landed in 2020, reveals significant interaction between the rocks and liquid water, according to a study published in the journal Science. Those rocks also contain evidence consistent with the presence of organic compounds.

The existence of organic compounds (chemical compounds with carbon–hydrogen bonds) is not direct evidence of life, as these compounds can be created through nonbiological processes.

Perseverance previously found organic compounds at Jezero's delta. Deltas are fan-shaped geologic formations created at the intersection of a river and a lake at the edge of the crater. Mars 2020 mission scientists had been particularly interested in the Jezero delta because such formations are created when a river transporting fine-grained sediments enter a deeper, slower-moving body of water. As the river water spreads out, it abruptly slows down, depositing the sediments it is carrying—and in so doing, traps and preserves any microorganisms that may exist in the water.

Astrophysicists Hunt for Second-Closest Supermassive Black Hole

Illustration Credit: Scott Anttila Anttler

Two astrophysicists at the Center for Astrophysics | Harvard & Smithsonian have suggested a way to observe what could be the second-closest supermassive black hole to Earth: a behemoth 3 million times the mass of the Sun, hosted by the dwarf galaxy Leo I.

The supermassive black hole, labeled Leo I*, was first proposed by an independent team of astronomers in late 2021. The team noticed stars picking up speed as they approached the center of the galaxy — evidence for a black hole — but directly imaging emission from the black hole was not possible.

Now, CfA astrophysicists Fabio Pacucci and Avi Loeb suggest a new way to verify the supermassive black hole's existence; their work is described in a study published today in The Astrophysical Journal Letters.

"Black holes are very elusive objects, and sometimes they enjoy playing hide-and-seek with us," says Fabio Pacucci, lead author of the ApJ Letters study. "Rays of light cannot escape their event horizons, but the environment around them can be extremely bright — if enough material falls into their gravitational well. But if a black hole is not accreting mass, instead, it emits no light and becomes impossible to find with our telescopes."

Tuesday, November 22, 2022

Webb Reveals an Exoplanet Atmosphere as Never Seen Before

The atmospheric composition of the hot gas giant exoplanet WASP-39 b has been revealed by the NASA/ESA/CSA James Webb Space Telescope. This graphic shows four transmission spectra from three of Webb’s instruments operated in four instrument modes. All are plotted on a common scale extending from 0.5 to 5.5 microns.  A transmission spectrum is made by comparing starlight filtered through a planet’s atmosphere as it moves in front of the star, to the unfiltered starlight detected when the planet is beside the star. Each of the data points (white circles) on these graphs represents the amount of a specific wavelength of light that is blocked by the planet and absorbed by its atmosphere. Wavelengths that are preferentially absorbed by the atmosphere appear as peaks in the transmission spectrum.  The blue line is a best-fit model that takes into account the data, the known properties of WASP-39 b and its star (e.g., size, mass, temperature), and assumed characteristics of the atmosphere. Researchers can vary the parameters in the model – changing unknown characteristics like cloud height in the atmosphere and abundances of various gases – to get a better fit and further understand what the atmosphere is really like.  At upper left, data from NIRISS shows fingerprints of potassium (K), water (H2O), and carbon monoxide (CO). At upper right, data from NIRCam shows a prominent water signature. At lower left, data from NIRSpec indicates water, sulfur dioxide (SO2), carbon dioxide (CO2), and carbon monoxide (CO). At lower right, additional NIRSpec data reveals all of these molecules as well as sodium (Na). 
Full Size Original
Credit: NASA, ESA, CSA, J. Olmsted (STScI)

The NASA/ESA/CSA James Webb Space Telescope just scored another first: a molecular and chemical portrait of a distant world’s skies. While Webb and other space telescopes, including the NASA/ESA Hubble Space Telescope, have previously revealed isolated ingredients of this heated planet’s atmosphere, the new readings provide a full menu of atoms, molecules, and even signs of active chemistry and clouds. The latest data also give a hint of how these clouds might look up close: broken up rather than as a single, uniform blanket over the planet.

The telescope’s array of highly sensitive instruments was trained on the atmosphere of WASP-39 b, a “hot Saturn” (a planet about as massive as Saturn but in an orbit tighter than Mercury) orbiting a star some 700 light-years away. This Saturn-sized exoplanet was one of the first examined by the NASA/ESA/CSA James Webb Space Telescope when it began regular science operations. The results have excited the exoplanet science community. Webb’s exquisitely sensitive instruments have provided a profile of WASP-39 b’s atmospheric constituents and identified a plethora of contents, including water, sulfur dioxide, carbon monoxide, sodium and potassium.

Monday, November 21, 2022

Short gamma-ray bursts traced farther into distant universe

Credit: W. M. Keck Observatory/Adam Makarenko

A Northwestern University-led team of astronomers has developed the most extensive inventory to date of the galaxies where short gamma-ray bursts (SGRBs) originate.

Using several highly sensitive instruments and sophisticated galaxy modeling, the researchers pinpointed the galactic homes of 84 SGRBs and probed the characteristics of 69 of the identified host galaxies. Among their findings, they discovered that about 85% of the studied SGRBs come from young, actively star-forming galaxies.

The astronomers also found that more SGRBs occurred at earlier times, when the universe was much younger — and with greater distances from their host galaxies’ centers — than previously known. Surprisingly, several SGRBs were spotted far outside their host galaxies — as if they were “kicked out,” a finding that raises questions as to how they were able to travel so far away.

“This is the largest catalog of SGRB host galaxies to ever exist, so we expect it to be the gold standard for many years to come,” said Anya Nugent, a Northwestern graduate student who led the study focused on modeling host galaxies. “Building this catalog and finally having enough host galaxies to see patterns and draw significant conclusions is exactly what the field needed to push our understanding of these fantastic events and what happens to stars after they die.”

Tuesday, November 15, 2022

Cosmic chocolate pralines: general neutron star structure revealed

The study of the sound speed has revealed that heavy neutron stars have a stiff mantle and a soft core, while light neutron stars have a soft mantle and a stiff core – much like different chocolate pralines Illustration Credit: P. Kiefer/L. Rezzolla

Through extensive model calculations, physicists at Goethe University Frankfurt have reached general conclusions about the internal structure of neutron stars, where matter reaches enormous densities: depending on their mass, the stars can have a core that is either very stiff or very soft. The findings were published simultaneously in two articles today in The Astrophysical Journal Letters.

So far, little is known about the interior of neutron stars, those extremely compact objects that can form after the death of a star: the mass of our sun or even more is compressed into a sphere with the diameter of a large city. Since their discovery more than 60 years ago, scientists have been trying to decipher their structure. The greatest challenge is to simulate the extreme conditions inside neutron stars, as they can hardly be recreated on Earth in the laboratory. There are therefore many models in which various properties – from density and temperature – are described with the help of so-called equations of state. These equations attempt to describe the structure of neutron stars from the stellar surface to the inner core.

Monday, November 14, 2022

Study of ‘polluted’ white dwarfs finds that stars and planets grow together

Study of ‘polluted’ white dwarfs finds that stars and planets grow together 
Credit: Amanda Smith

A team of astronomers have found that planet formation in our young Solar System started much earlier than previously thought, with the building blocks of planets growing at the same time as their parent star.

A study of some of the oldest stars in the Universe suggests that the building blocks of planets like Jupiter and Saturn begin to form while a young star is growing. It had been thought that planets only form once a star has reached its final size, but new results, published in the journal Nature Astronomy, suggest that stars and planets ‘grow up’ together.

The research, led by the University of Cambridge, changes our understanding of how planetary systems, including our own Solar System, formed, potentially solving a major puzzle in astronomy.

“We have a pretty good idea of how planets form, but one outstanding question we’ve had is when they form: does planet formation start early, when the parent star is still growing, or millions of years later?” said Dr Amy Bonsor from Cambridge’s Institute of Astronomy, the study’s first author.

To attempt to answer this question, Bonsor and her colleagues studied the atmospheres of white dwarf stars – the ancient, faint remnants of stars like our Sun – to investigate the building blocks of planet formation. The study also involved researchers from the University of Oxford, the Ludwig-Maximilians-Universität in Munich, the University of Groningen and the Max Planck Institute for Solar System Research, Gottingen.

“Some white dwarfs are amazing laboratories, because their thin atmospheres are almost like celestial graveyards,” said Bonsor.

Monday, November 7, 2022

Early planetary migration can explain missing planets

An illustration of the variations among the more than 5,000 known exoplanets discovered since the 1990s.
Image Credit: of NASA/JPL-Caltech

A new model that accounts for the interplay of forces acting on newborn planets can explain two puzzling observations that have cropped up repeatedly among the more than 3,800 planetary systems cataloged to date.

One puzzle known as the “radius valley” refers to the rarity of exoplanets with a radius about 1.8 times that of Earth. NASA’s Kepler spacecraft observed planets of this size about 2-3 times less frequently than it observed super-Earths with radii about 1.4 times that of Earth and mini-Neptunes with radii about 2.5 times Earth’s. The second mystery, known as “peas in a pod,” refers to neighboring planets of similar size that have been found in hundreds of planetary systems. Those include TRAPPIST-1 and Kepler-223, which also feature planetary orbits of near-musical harmony.

“I believe we are the first to explain the radius valley using a model of planet formation and dynamical evolution that self-consistently accounts for multiple constraints of observations,” said Rice University’s André Izidoro, corresponding author of a study published this week in Astrophysical Journal Letters. “We’re also able to show that a planet-formation model incorporating giant impacts is consistent with the peas-in-a-pod feature of exoplanets.”

Thursday, November 3, 2022

Polarized X-Rays Reveal Shape, Orientation of Extremely Hot Matter Around Black Hole

An artist’s impression of the Cygnus X-1 system, with the black hole appearing in the center and its companion star on the left. New measurements from Cygnus X-1, reported Nov. 3 in the journal Science, represent the first observations of a mass-accreting black hole from the Imaging X-Ray Polarimetry Explorer (IXPE) mission, an international collaboration between NASA and the Italian Space Agency.
Illustration Credit: John Paice

Researchers’ recent observations of a stellar-mass black hole called Cygnus X-1 reveal new details about the configuration of extremely hot matter in the region immediately surrounding the black hole.

Matter is heated to millions of degrees as it is pulled toward a black hole. This hot matter glows in X-rays. Researchers are using measurements of the polarization of these X-rays to test and refine models that describe how black holes swallow matter, becoming some of the most luminous sources of light — including X-rays — in the universe.

The new measurements from Cygnus X-1, reported Nov. 3 in the journal Science, represent the first observations of a mass-accreting black hole from the Imaging X-Ray Polarimetry Explorer (IXPE) mission, an international collaboration between NASA and the Italian Space Agency (ASI). Cygnus X-1 is one of the brightest X-ray sources in our galaxy, consisting of a 21 solar mass black hole in orbit with a 41 solar mass companion star.

Tuesday, November 1, 2022

As dense as it gets: New Model for Matter in Neutron Star Collisions

Illustration of the new method: the researchers use five-dimensional black holes (right) to calculate the phase diagram of strongly coupled matter (middle), enabling simulations of neutron star mergers and the produced gravitational waves (left).
Source/Credit: Goethe University

With the exception of black holes, neutron stars are the densest objects in our universe. As their name suggests, neutron stars are mainly made of neutrons. However, our knowledge about the matter produced during the collision of two neutron stars is still limited. Scientists from Goethe University Frankfurt and the Asia Pacific Center for Theoretical Physics in Pohang have now developed a new model that gives insights about matter under such extreme conditions.

After a massive star has burned its fuel and explodes as a supernova, an extremely compact object, called a neutron star, can be formed. Neutron stars are extraordinarily dense: To reach the density inside them, one would need to squeeze a massive body like our sun down to the size of a city like Frankfurt. In 2017, gravitational waves, the small ripples in spacetime that are produced during a collision of two neutron stars, could be directly measured here on earth for the first time. However, the composition of the resulting hot and dense merger product is not known precisely. It is still an open question, for instance, whether quarks, which are otherwise trapped in neutrons, can appear in free form after the collision. Dr. Christian Ecker from the Institute for Theoretical Physics of Goethe University Frankfurt, Germany, and Dr. Matti Järvinen and Dr. Tuna Demircik from the Asia Pacific Center for Theoretical Physics in Pohang, South Korea, have now developed a new model that allows them to get one step closer to answering this question.

Monday, October 31, 2022

Largest Potentially Hazardous Asteroid Detected in Eight Years

Twilight observations with the U.S. Department of Energy-fabricated Dark Energy Camera at Cerro Tololo Inter-American Observatory in Chile, a program of NSF’s NOIRLab, have enabled astronomers to spot three near-Earth asteroids, or NEAs, hiding in the glare of the sun. These NEAs are part of an elusive population that lurks inside the orbits of Earth and Venus. One of the asteroids is the largest object that is potentially hazardous to Earth to be discovered in the last eight years.
Image Credit: DOE/FNAL/DECam/CTIO/NOIRLab/NSF/AURA/J. da Silva/Spaceengine

Twilight observations with the US Department of Energy-fabricated Dark Energy Camera at Cerro Tololo Inter-American Observatory in Chile, a Program of NSF's NOIRLab, have enabled astronomers to spot three near-Earth asteroids (NEA) hiding in the glare of the Sun. These NEAs are part of an elusive population that lurks inside the orbits of Earth and Venus. One of the asteroids is the largest object that is potentially hazardous to Earth to be discovered in the last eight years.

An international team using the Dark Energy Camera (DECam) mounted on the Víctor M. Blanco 4-meter Telescope at Cerro Tololo Inter-American Observatory in Chile, a Program of NSF’s NOIRLab, has discovered three new near-Earth asteroids (NEAs) hiding in the inner Solar System, the region interior to the orbits of Earth and Venus. This is a notoriously challenging region for observations because asteroid hunters have to contend with the glare of the Sun.

By taking advantage of the brief yet favorable observing conditions during twilight, however, the astronomers found an elusive trio of NEAs. One is a 1.5-kilometer-wide asteroid called 2022 AP7, which has an orbit that may someday place it in Earth’s path. The other asteroids, called 2021 LJ4 and 2021 PH27, have orbits that safely remain completely interior to Earth’s orbit. Also, of special interest to astronomers and astrophysicists, 2021 PH27 is the closest known asteroid to the Sun. As such, it has the largest general-relativity effects [1] of any object in our Solar System and during its orbit its surface gets hot enough to melt lead.

Ghost of a giant star

This image shows a spectacular view of the orange and pink clouds that make up what remains after the explosive death of a massive star — the Vela supernova remnant. This detailed image consists of 554 million pixels, and is a combined mosaic image of observations taken with the 268-million-pixel OmegaCAM camera at the VLT Survey Telescope, hosted at ESO’s Paranal Observatory.   OmegaCAM can take images through several filters that each let the telescope see the light emitted in a distinct color. To capture this image, four filters have been used, represented here by a combination of magenta, blue, green and red. The result is an extremely detailed and stunning view of both the gaseous filaments in the remnant and the foreground bright blue stars that add sparkle to the image. 
Hi-Res Zoomable Image
Credit: ESO/VPHAS+ team. Acknowledgement: Cambridge Astronomical Survey Unit

A spooky spider web, magical dragons or wispy trails of ghosts? What do you see in this image of the Vela supernova remnant? This beautiful tapestry of colors shows the ghostly remains of a gigantic star, and was captured here in incredible detail with the VLT Survey Telescope, hosted at the European Southern Observatory’s (ESO’s) Paranal site in Chile.

The wispy structure of pink and orange clouds is all that remains of a massive star that ended its life in a powerful explosion around 11 000 years ago. When the most massive stars reach the end of their life, they often go out with a bang, in an outburst called a supernova. These explosions cause shock waves that move through the surrounding gas, compressing it and creating intricate thread-like structures. The energy released heats the gaseous tendrils, making them shine brightly, as seen in this image.

In this 554-million-pixel image, we get an extremely detailed view of the Vela supernova remnant, named after the southern constellation Vela (The Sails). You could fit nine full Moons in this entire image, and the whole cloud is even larger. At only 800 light-years away from Earth, this dramatic supernova remnant is one of the closest known to us.

Wednesday, October 19, 2022

Researchers discover new monster black hole 'practically in our back yard'

Dr. Sukanya Chakrabarti, the Pei-Ling Chan Endowed Chair in the Department of Physics & Astronomy, is the paper’s lead author. 
Credit: Michael Mercier / UAH

The discovery of a so-called monster black hole that has about 12 times the mass of the sun is detailed in a new Astrophysical Journal research submission, the lead author of which is Dr. Sukanya Chakrabarti, a physics professor at The University of Alabama in Huntsville (UAH).

“It is closer to the sun than any other known black hole, at a distance of 1,550 light years,” says Dr. Chakrabarti, the Pei-Ling Chan Endowed Chair in the Department of Physics at UAH, a part of the University of Alabama System. “So, it's practically in our backyard.”

Black holes are seen as exotic because, although their gravitational force is clearly felt by stars and other objects in their vicinity, no light can escape a black hole so they can’t be seen in the same way as visible stars.

“In some cases, like for supermassive black holes at the centers of galaxies, they can drive galaxy formation and evolution,” Dr. Chakrabarti says.

“It is not yet clear how these noninteracting black holes affect galactic dynamics in the Milky Way. If they are numerous, they may well affect the formation of our galaxy and its internal dynamics.”

The Most Precise Accounting Yet of Dark Energy and Dark Matter

G299 was left over by a particular class of supernovas called Type Ia. 
Credit: NASA/CXC/U.Texas

 Astrophysicists have performed a powerful new analysis that places the most precise limits yet on the composition and evolution of the universe. With this analysis, dubbed Pantheon+, cosmologists find themselves at a crossroads.

Pantheon+ convincingly finds that the cosmos is composed of about two-thirds dark energy and one-third matter — mostly in the form of dark matter — and is expanding at an accelerating pace over the last several billion years. However, Pantheon+ also cements a major disagreement over the pace of that expansion that has yet to be solved.

By putting prevailing modern cosmological theories, known as the Standard Model of Cosmology, on even firmer evidentiary and statistical footing, Pantheon+ further closes the door on alternative frameworks accounting for dark energy and dark matter. Both are bedrocks of the Standard Model of Cosmology but have yet to be directly detected and rank among the model's biggest mysteries. Following through on the results of Pantheon+, researchers can now pursue more precise observational tests and hone explanations for the ostensible cosmos.

"With these Pantheon+ results, we are able to put the most precise constraints on the dynamics and history of the universe to date," says Dillon Brout, an Einstein Fellow at the Center for Astrophysics | Harvard & Smithsonian. "We've combed over the data and can now say with more confidence than ever before how the universe has evolved over the eons and that the current best theories for dark energy and dark matter hold strong."

Tuesday, October 18, 2022

Algae Could be Instrumental in Making Human Exploration of Mars Possible

 A researcher working in UNLV geoscientist Elisabeth "Libby" Hausrath's lab.
Credit: University of Nevada, Las Vegas

While the world is marveling over the first images and data now coming from NASA’s Perseverance rover mission seeking signs of ancient microscopic life on Mars, a team of UNLV scientists is already hard at work on the next step: What if we could one day send humans to the Red Planet?

There’s a lot to consider when sending people, though. Human explorers, unlike their rover counterparts, require oxygen and food, for starters. It also takes about six to nine months — both ways — just in travel time. And then there’s the air itself. Martian air is roughly 98% carbon dioxide (Earth’s is a fraction of 1% for comparison) and the air temperature averages an extremely frigid -81 degrees.

It’s these challenges that UNLV geochemist and NASA Mars 2020 team scientist Libby Hausrath and postdoctoral researcher Leena Cycil, a microbial ecologist, are exploring. And a big part of the answer? Algae.

“Extremophilic algae” are types of algae known for their ability to thrive in extreme environments such as high-altitude snowy mountains or hypersaline lakes. These algae love carbon dioxide and can use it to produce oxygen. They also are edible, dense with nutrients, and grow quickly. Extremophiles’ helpful characteristics allow them to grow in some of the most inhospitable environments on Earth, possibly even in conditions similar to Mars.

Thursday, October 13, 2022

Heaviest element yet detected in an exoplanet atmosphere

This artist’s impression shows an ultra-hot exoplanet, a planet beyond our Solar System, as it is about to transit in front of its host star. When the light from the star passes through the planet’s atmosphere, it is filtered by the chemical elements and molecules in the gaseous layer. With sensitive instruments, the signatures of those elements and molecules can be observed from Earth. Using the ESPRESSO instrument of ESO’s Very Large Telescope, astronomers have found the heaviest element yet in an exoplanet's atmosphere, barium, in the two ultra-hot Jupiters WASP-76 b and WASP-121 b. 
Credit: ESO/M. Kornmesser

Using the European Southern Observatory’s Very Large Telescope (ESO’s VLT), astronomers have discovered the heaviest element ever found in an exoplanet atmosphere — barium. They were surprised to discover barium at high altitudes in the atmospheres of the ultra-hot gas giants WASP-76 b and WASP-121 b — two exoplanets, planets which orbit stars outside our Solar System. This unexpected discovery raises questions about what these exotic atmospheres may be like.

“The puzzling and counterintuitive part is: why is there such a heavy element in the upper layers of the atmosphere of these planets?” says Tomás Azevedo Silva, a PhD student at the University of Porto and the Instituto de Astrofísica e Ciências do Espaço (IA) in Portugal who led the study published today in Astronomy & Astrophysics.

WASP-76 b and WASP-121 b are not ordinary exoplanets. Both are known as ultra-hot Jupiters as they are comparable in size to Jupiter whilst having extremely high surface temperatures soaring above 1000°C. This is due to their close proximity to their host stars, which also means an orbit around each star takes only one to two days. This gives these planets rather exotic features; in WASP-76 b, for example, astronomers suspect it rains iron.

Wednesday, October 12, 2022

Black Hole Spews Out Material Years After Shredding Star

Artist’s illustration of tidal disruption event AT2019dsg where a supermassive black hole spaghettifies and gobbles down a star. Some of the material is not consumed by the black hole and is flung back out into space. 
Resized Image using AI by SFLORG
Credit: DESY, Science Communication Lab

In October 2018, a small star was ripped to shreds when it wandered too close to a black hole in a galaxy located 665 million light years away from Earth. Though it may sound thrilling, the event did not come as a surprise to astronomers who occasionally witness these violent incidents while scanning the night sky.

But nearly three years after the massacre, the same black hole is lighting up the skies again — and it hasn’t swallowed anything new, scientists say.

“This caught us completely by surprise — no one has ever seen anything like this before,” says Yvette Cendes, a research associate at the Center for Astrophysics | Harvard & Smithsonian (CfA) and lead author of a new study analyzing the phenomenon.

The team concludes that the black hole is now ejecting material traveling at half of the speed of light, but are unsure why the outflow was delayed by several years. The results, described this week in the Astrophysical Journal, may help scientists better understand black holes’ feeding behavior, which Cendes likens to “burping” after a meal.

Tuesday, October 11, 2022

Broccoli gas: a better way to find life in space

Photo credit: Engin Akyurt

Broccoli, along with other plants and microorganisms, emit gases to help them expel toxins. Scientists believe these gases could provide compelling evidence of life on other planets.

These types of gases are made when organisms add a carbon and three hydrogen atoms to an undesirable chemical element. This process, called methylation, can turn potential toxins into gases that float safely away into the atmosphere. If these gases were to be detected in the atmosphere of another planet using telescopes, they would be suggestive of life somewhere on that planet.

“Methylation is so widespread on Earth, we expect life anywhere else to perform it,” said Michaela Leung, UCR planetary scientist. “Most cells have mechanisms for expelling harmful substances.”

One methylated gas, methyl bromide, has several advantages over other gases traditionally targeted in the search for life outside our solar system. Leung led a study, newly published in the Astrophysical Journal, that explored and quantified these advantages.

For one, methyl bromide remains in the atmosphere for a shorter time than traditional biosignature gases.

Tuesday, October 4, 2022

Exoplanet hunters should check for N2O

TRAPPIST-1 system
Credit: NASA/JPL-Caltech

Scientists at UC Riverside are suggesting something is missing from the typical roster of chemicals that astrobiologists use to search for life on planets around other stars — laughing gas.

Chemical compounds in a planet’s atmosphere that could indicate life, called biosignatures, typically include gases found in abundance in Earth’s atmosphere today.

“There’s been a lot of thought put into oxygen and methane as biosignatures. Fewer researchers have seriously considered nitrous oxide, but we think that may be a mistake,” said Eddie Schwieterman, an astrobiologist in UCR’s Department of Earth and Planetary Sciences.

This conclusion, and the modeling work that led to it, are detailed in an article published today in the Astrophysical Journal.

To reach it, Schwieterman led a team of researchers that determined how much nitrous oxide living things on a planet similar to Earth could possibly produce. They then made models simulating that planet around different kinds of stars and determined amounts of N2O that could be detected by an observatory like the James Webb Space Telescope.

Saturday, October 1, 2022

Exploring Europa Possible with Silicon-Germanium Transistor Technology

Europa Image
Credit: NASA/JPL-Caltech/SETI Institute

Europa is more than just one of Jupiter’s many moons – it’s also one of most promising places in the solar system to look for extraterrestrial life. Under 10 kilometers of ice is a liquid water ocean that could sustain life. But with surface temperatures at -180 Celsius and with extreme levels of radiation, it’s also one of the most inhospitable places in the solar system. Exploring Europa could be possible in the coming years thanks to new applications for silicon-germanium transistor technology research at Georgia Tech.

Regents’ Professor John D. Cressler in the School of Electrical and Computer Engineering (ECE) and his students have been working with silicon-germanium heterojunction bipolar transistors (SiGe HBTs) for decades and have found them to have unique advantages in extreme environments like Europa.

“Due to the way that they're made, these devices actually survive those extreme conditions without any changes made to the underlying technology itself,” said Cressler, who is the project investigator. “You can build it for what you want it to do on Earth, and you then can use it in space.”

The researchers are in year one of a three-year grant in the NASA Concepts for Ocean Worlds Life Detection Technology (COLDTech) program to design the electronics infrastructure for upcoming Europa surface missions. NASA plans to launch the Europa Clipper in 2024, an orbiting spacecraft that will map the oceans of Europa, and then eventually send a landing vehicle, Europa Lander, to drill through the ice and explore its ocean. But it all starts with electronics that can function in Europa’s extreme environment.

Cressler and his students, together with researchers from NASA Jet Propulsion Lab (JPL) and the University of Tennessee (UT), demonstrated the capabilities of SiGe HBTs for this hostile environment in a paper presented at the IEEE Nuclear and Space Radiation Effects Conference in July.

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