The Daily Galaxy -Great Discoveries Channel, is an eclectic text and video presentation of news and original insights on science, space exploration and the environment and their reflections in popular culture (film, books, events). It provides news and original insights on science, space exploration, cosmology, astrobiology, and astrophysics.
"We should have all the matter today that we had back when the universe was 400,000 years old," said Philip Kaaret, HaloSat's principal investigator at the University of Iowa (UI), which leads the mission. "Where did it go? The answer to that question can help us learn how we got from the CMB's uniform state to the large-scale structures we see today."
Astronomers keep coming up short when they survey "normal" matter, the material that makes up galaxies, stars and planets. A new NASA-sponsored CubeSat mission called HaloSat, deployed from the International Space Station on July 13, will help scientists search for the universe's missing matter by studying X-rays from hot gas surrounding our Milky Way galaxy.
The cosmic microwave background (CMB) is the oldest light in the universe, radiation from when it was 400,000 years old. Calculations based on CMB observations indicate the universe contains: 5 percent normal matter protons, neutrons and other subatomic particles; 25 percent dark matter, a substance that remains unknown; and 70 percent dark energy, a negative pressure accelerating the expansion of the universe.
As the universe expanded and cooled, normal matter coalesced into gas, dust, planets, stars and galaxies. But when astronomers tally the estimated masses of these objects, they account for only about half of what cosmologists say should be present.
Researchers think the missing matter may be in hot gas located either in the space between galaxies or in galactic halos, extended components surrounding individual galaxies.
HaloSat will study gas in the Milky Way's halo that runs about 2 million degrees Celsius (3.6 million degrees Fahrenheit). At such high temperatures, oxygen sheds most of its eight electrons and produces the X-rays HaloSat will measure.
Other X-ray telescopes, like NASA's Neutron star Interior Composition Explorer and the Chandra X-ray Observatory, study individual sources by looking at small patches of the sky. HaloSat will look at the whole sky, 100 square degrees at a time, which will help determine if the diffuse galactic halo is shaped more like a fried egg or a sphere.
"If you think of the galactic halo in the fried egg model, it will have a different distribution of brightness when you look straight up out of it from Earth than when you look at wider angles," said Keith Jahoda, a HaloSat co-investigator and astrophysicist at NASA's Goddard Space Flight Center in Greenbelt, Maryland. "If it's in some quasi-spherical shape, compared to the dimensions of the galaxy, then you expect it to be more nearly the same brightness in all directions."
The halo's shape will determine its mass, which will help scientists understand if the universe's missing matter is in galactic halos or elsewhere.
HaloSat will be the first astrophysics mission that minimizes the effects of X-rays produced by solar wind charge exchange. This emission occurs when the solar wind, an outflow of highly charged particles from the Sun, interacts with uncharged atoms like those in Earth's atmosphere. The solar wind particles grab electrons from the uncharged atoms and emit X-rays. These emissions exhibit a spectrum similar to what scientists expect to see from the galactic halo.
"Every observation we make has this solar wind emission in it to some degree, but it varies with time and solar wind conditions," said Kip Kuntz, a HaloSat co-investigator at Johns Hopkins University in Baltimore. "The variations are so hard to calculate that many people just mention it and then ignore it in their observations."
In order to minimize these solar wind X-rays, HaloSat will collect most of its data over 45 minutes on the nighttime half of its 90-minute orbit around Earth. On the daytime side, the satellite will recharge using its solar panels and transmit data to NASA's Wallops Flight Facility in Virginia, which relays the data to the mission's operations control center at Blue Canyon Technologies in Boulder, Colorado.
HaloSat measures 4-by-8-by-12 inches (about 10-by-20-by-30 centimeters) and weighs about 26 pounds (12 kilograms). It is the first science-focused astrophysics CubeSat mission, but a CubeSat called the Arcsecond Space Telescope Enabling Research in Astrophysics (ASTERIA), led by NASA's Jet Propulsion Laboratory in Pasadena, California, launched in 2017 to demonstrate astrophysics technology. CubeSat missions usually take around three years to develop through launch and the start of data collection, the optimal amount of time for undergraduate or graduate students to be involved from start to finish.
HaloSat is a NASA CubeSat mission led by the University of Iowa in Iowa City. Additional partners include NASA's Goddard Space Flight Center in Greenbelt, Maryland, NASA's Wallops Flight Facility on Wallops Island, Virginia, Blue Canyon Technologies in Boulder, Colorado, Johns Hopkins University in Baltimore and with important contributions from partners in France. HaloSat was selected through NASA's CubeSat Launch Initiative as part of the 23rd installment of the Educational Launch of Nanosatellites missions.
The Daily Galaxy via NASA/Goddard Space Flight Center
"For most of Earth history our planet was populated with microbes, and projecting into the future they will likely be the stewards of the planet long after we are gone," says Crockford, now a postdoctoral researcher at Princeton University and Israel's Weizmann Institute of Science. "Understanding the environments they shape not only informs us of our own past and how we got here, but also provides clues to what we might find if we discover an inhabited exoplanet."
A sample of ancient oxygen, teased out of a 1.4 billion-year-old evaporative lake deposit in Ontario, provides fresh evidence of what the Earth's atmosphere and biosphere were like during the interval leading up to the emergence of animal life.
The findings, published in the journal Nature, represent the oldest measurement of atmospheric oxygen isotopes by nearly a billion years. The results support previous research suggesting that oxygen levels in the air during this time in Earth history were a tiny fraction of what they are today due to a much less productive biosphere.
"It has been suggested for many decades now that the composition of the atmosphere has significantly varied through time," says Peter Crockford, who led the study as a PhD student at McGill University. "We provide unambiguous evidence that it was indeed much different 1.4 billion years ago."
The study provides the oldest gauge yet of what earth scientists refer to as "primary production," in which micro-organisms at the base of the food chain - algae, cyanobacteria, and the like - produce organic matter from carbon dioxide and pour oxygen into the air.
"This study shows that primary production 1.4 billion years ago was much less than today," says senior co-author Boswell Wing, who helped supervise Crockford's work at McGill. "This means that the size of the global biosphere had to be smaller, and likely just didn't yield enough food - organic carbon - to support a lot of complex macroscopic life," says Wing, now an associate professor of geological sciences at University of Colorado at Boulder.
To come up with these findings, Crockford teamed up with colleagues from Yale University, University of California Riverside, and Lakehead University in Thunder Bay, Ontario, who had collected pristine samples of ancient salts, known as sulfates, found in a sedimentary rock formation north of Lake Superior. Crockford shuttled the samples to Louisiana State University, where he worked closely with co-authors Huiming Bao, Justin Hayles, and Yongbo Peng, whose lab is one of a handful in the world using a specialized mass-spectrometry technique capable of probing such materials for rare oxygen isotopes within sulfates.
The work also sheds new light on a stretch of Earth's history known as the "boring billion" because it yielded little apparent biological or environmental change.
"Subdued primary productivity during the mid-Proterozoic era - roughly 2 billion to 800 million years ago - has long been implied, but no hard data had been generated to lend strong support to this idea," notes Galen Halverson, a co-author of the study and associate professor of earth and planetary sciences at McGill. "That left open the possibility that there was another explanation for why the middle Proterozoic ocean was so uninteresting, in terms of the production and deposit of organic carbon." Crockford's data "provide the direct evidence that this boring carbon cycle was due to low primary productivity."
Deep in the ocean's twilight zone, swarms of ravenous single-celled organisms may be altering Earth's carbon cycle in ways scientists never expected, according to a new study from Florida State University researchers. In the area 100 to 1,000 meters below the ocean's surface—dubbed the twilight zone because of its largely impenetrable darkness—scientists found that tiny organisms called phaeodarians are consuming sinking, carbon-rich particles before they settle on the seabed, where they would otherwise be stored and sequestered from the atmosphere for millennia.
This discovery, researchers suggest, could indicate the need for a re-evaluation of how carbon circulates throughout the ocean, and a new appraisal of the role these microorganisms might play in Earth's shifting climate.
Lead researcher and FSU Assistant Professor of Oceanography Mike Stukel, who conducted the study with the California Current Ecosystem Long-Term Ecological Research program, investigates the biological pump—the process by which carbon is transported from the surface to the deep ocean.
"Carbon dioxide is constantly diffusing into the ocean from the atmosphere and back into the atmosphere from the ocean," Stukel said. "In the surface ocean, when phytoplankton do photosynthesis, they're taking up carbon dioxide. But phytoplankton only have lifespans of days to a week, so those phytoplankton are likely to die in the surface ocean—usually by getting eaten by small organisms like krill."
When krill and other zooplankton breathe, they release carbon dioxide back into the surface ocean, and eventually back into the atmosphere. Typically, carbon dioxide in the surface ocean and atmosphere remain balanced at a near equilibrium.
The only way the ocean experiences a net uptake of carbon dioxide from the atmosphere is if the organic carbon at the surface is transported to the deep ocean, usually in the form of sinking particles.
Particles can sink from the surface ocean for any number of reasons. Dead organisms, fecal matter or amalgamated packages of organic particles are all common vehicles for carbon transport. Diatoms, a type of abundant phytoplankton that perform roughly a quarter of the world's photosynthesis, produce glass-like silica shells that make them substantially denser than the water, causing them to quickly sink.
If these sinking particles were to reach the deep ocean unobstructed, their carbon would be withheld from the atmosphere for hundreds of years. But, as Stukel and his team found, that's not always the case.
Using an advanced camera system that allowed researchers to identify organisms as small as 500 microns (half the thickness of a dime), the team discovered a profusion of microorganisms—far more than they expected—in the crucial ocean twilight zone. Their major question: What were the roles of these organisms, and phaeodarians specifically, in consuming sinking particles?
"By quantifying how many were there and then quantifying the proportion of particles they would be intercepting, we were able to calculate that they could be consuming as much as about 20 percent of the particles sinking out of the surface layer," Stukel said. "And this was just for one particular family of phaeodarians, called aulosphaeridae."
When sinking particles are consumed, those particles are necessarily prevented from reaching the deep ocean. The notion that one group of microorganisms could be consuming 20 percent of the carbon-rich particles sinking from the surface waters of this limited study area, Stukel said, suggests that microorganisms around the world could be playing a far more outsized role in the carbon cycle than scientists previously believed.
While at some points aulosphaeridae would be so abundant as to consume up to 30 percent of sinking particles, other times the organisms were barely present at all. Better understanding this variability in abundance of aulosphaeridae and similar organisms can help researchers like Stukel more accurately predict how the biological pump might evolve in the future.
"Our ability to understand how these things will change is important in understanding how the global carbon cycle is going to shift," Stukel said. "We need to learn what's going on in the rest of the world, and we need to know what causes these huge changes from when these organisms are a really dominant player to when they're a marginal player."
Crossing this boundary with a spacecraft will be similar, symbolically, to the moment when the Voyager 1 probe entered interstellar space in 2012, says Justin Kasper, a physicist at the University of Michigan. The moment will mark humanity’s passage to another realm in the Solar System. “I’m confident that something special will happen.”
Step aside, Icarus: NASA has made a spacecraft that can fly through the Sun’s atmosphere without melting. On 4 August, if all goes to plan, the US$1.5-billion Parker Solar Probe will lift off from a launch pad at Florida’s Cape Canaveral. Just three months later, it will whiz far closer to the Sun than any spacecraft has ever come, to take the first-ever direct measurements of the star's maelstrom of energy.
But that's just the beginning, continues Alexandra Witze in today's Nature. Over the next 7 years, the craft will loop around the Sun 23 more times, passing nearer and nearer — ultimately flying about 6.2 million kilometres above the surface, well within the solar corona. That’s nearly seven times closer than the record mark set by the German Helios 2 spacecraft in 1976.
The Parker Solar Probe aims to answer some of the biggest outstanding questions about the Sun, such as how its corona is heated to millions of degrees while the surface beneath it stays relatively cool1. The spacecraft will also visit the birthplace of the solar wind, a flood of energetic particles that streams outward into the Solar System at speeds of up to 800 kilometres a second. When the solar wind slams into Earth, it generates beautiful polar aurorae, but it can also disrupt satellite communications and navigation systems.
“We’re going to be right where all the interesting stuff happens,” says Nicola Fox, a solar physicist at the Johns Hopkins University Applied Physics Laboratory (APL) in Laurel, Maryland, and the mission’s project scientist.
Data from the deep-diving probe should allow researchers to better understand the complex picture of how particles, magnetic fields and energy combine in the Sun. “This is going to be such a game-changer,” says Nicholeen Viall, a solar physicist at NASA’s Goddard Space Flight Center in Greenbelt, Maryland.
Space physicists have dreamed of a mission that would fly through the solar corona, or at least travel inside the orbit of Mercury, the innermost planet, since 1958. That same year, Eugene Parker — the University of Chicago physicist for whom the probe is named — first proposed the existence of the solar wind2.
After decades on the drawing board, the mission is finally approaching launch. Eight weeks after lift-off, it will fly past Venus, using the planet’s gravity to slow down and slip into a tighter orbit around the Sun. Five weeks after that, on 3 November, the probe will make its first close approach — at more than 24 million kilometres, or 35 times the solar radius, from its surface.
From there, the spacecraft will loop around the Sun, drawing gradually closer as it flies past Venus 6 more times. That trajectory will give the probe ample time to gather data, says Yanping Guo, an engineer at APL who designed the mission trajectory.
Somewhere between the first close approach (at 35 solar radii) and its final ones (within 10 solar radii) the probe will encounter the Alfvén surface, a boundary where the solar wind becomes supersonic. Inside the Alfvén surface, the Sun’s magnetic field dominates; outside, the solar wind is more detached and streams away on its own.
The boundary might be more complicated than previously thought. A recent analysis of images of the outer corona taken by the STEREO spacecraft in 2014 reveals that the Alfvén surface might be more of a broadly, poorly defined zone that contains complicated magnetic structures. That suggests that the Parker Solar Probe will have the chance to measure a new and previously unexpected border zone. “It’s far more wild and woolly than we would have expected,” says Craig DeForest, a solar physicist at the Southwest Research Institute in Boulder, Colorado. He led the team behind the analysis, which was published on 18 July in the Astrophysical Journal4.
The Parker Solar Probe bristles with an array of instruments designed to sample the corona directly. Protecting them is a 2.4-metre-wide heat shield made of 11-centimetre-thick carbon foam sandwiched between layers of carbon composite. It can withstand temperatures of nearly 1,400 °C.
Solar panels power the spacecraft, but to keep them cool they have a water-tubing system similar to a car’s radiator. During the searing conditions of close approach, most of the solar panels will fold back to shelter in the heat shield’s shade.
Mission scientists hope that the Parker Solar Probe will kick off a new era of studying the Sun. In 2020, the European Space Agency plans to launch its Solar Orbiter spacecraft, which will study the Sun at higher latitudes and from a more distant point in space than the Parker Solar Probe will. Also by 2020, the Daniel K. Inouye Solar Telescope will come online in Hawaii, where it will make daily maps of the solar corona.
For his part, the 91-year-old Parker says that he is looking forward to seeing the waves and turbulence in the solar wind — which he predicted — measured by the probe that bears his name. “I expect to find some surprises,” he says.
To discover and confirm the presence of a planet around stars other than the Sun, astronomers wait until it has completed three orbits. However, this very effective technique has its drawbacks since it cannot confirm the presence of planets at relatively long periods (it is ideally suited for periods of a few days to a few months).
To overcome this obstacle, a team of astronomers under the direction of the University of Geneva (UNIGE) have developed a method that makes it possible to ensure the presence of a planet in a few months, even if it takes 10 years to circle its star: this new method is described for the first time in the journal Astronomy & Astrophysics.
The method of transits, consisting of detecting a dip in the luminosity of the host star at the time the planet passes, is a very effective technique to search for exoplanets. It makes it possible to estimate the radius of the planet, the inclination of the orbit and can be applied to a large number of stars at the same time. However, it has a significant limitation: since it is necessary to wait at least three passes in front of the star to confirm the existence of a planet, it is currently only suitable to detect planets with rather short orbital periods (typically from a few days to a few months). We would indeed have to wait more than 30 years to detect a planet similar to Jupiter which needs 11 years to make the full tour).
To overcome this obstacle, a team of astronomers led by researcher Helen Giles, from the Astronomy Department at the Faculty of Science of UNIGE and a member of the NCCR PlanetS, has developed an original method. By analysing data from the space telescope K2, one star showed a significant long-duration temporary decrease of luminosity, the signature of a possible transit, in other words, the passage of a planet in front of its star. "We had to analyse hundreds of light curves" explains the astronomer, to find one where such a transit was unequivocal.
This is data shown below is from the light curve of the EPIC248847494 star. The transit is clearly visible, on the upper right part of the image.
Helen Giles consulted recent data from the Gaïa mission to determine the diameter of the star referenced as EPIC248847494 and its distance, 1500 light-years away from the planet Earth. With that knowledge and the fact that the transit lasted 53 hours, she found that the planet is located at 4.5 times the distance from the Sun to the Earth, and that consequently it takes about 10 years to orbit once. The key question left to answer was whether it was a planet and not a star.
The Euler telescope of the UNIGE in Chile would provide the answer. By measuring the radial velocity of the star, which makes it possible to deduce the mass of the planet, she was able to show that the mass of the object is less than 13 times that of Jupiter -- well below the minimum mass of a star (at least 80 times the mass of Jupiter).
"This technique could be used to hunt habitable, Earth-like planets around stars like the Sun" enthuses Helen Giles, "we have already found Earths around red dwarf stars whose stellar radiation may have consequences on life which are not exactly known". With her method it will no longer be necessary to wait many years to know whether the detected single transit is due to the presence of a planet. "In the future, we could even see if the planet has one or more moons, like our Jupiter," she concludes.
"Jupiter just happened to be in the sky near the search fields where we were looking for extremely distant Solar System objects, so we were serendipitously able to look for new moons around Jupiter while at the same time looking for planets at the fringes of our Solar System," said Carnegie Institute's Scott S. Sheppard.
Twelve new moons orbiting Jupiter have been found--11 "normal" outer moons, and one that they're calling an "oddball." This brings Jupiter's total number of known moons to a whopping 79--the most of any planet in our Solar System. A team led by the Carnegie Institute first spotted the moons in the spring of 2017 while they were looking for very distant Solar System objects as part of the hunt for a possible massive planet far beyond Pluto.
In 2014, this same team found the object with the most-distant known orbit in our Solar System and was the first to realize that an unknown massive planet at the fringes of our Solar System, far beyond Pluto, could explain the similarity of the orbits of several small extremely distant objects. This putative planet is now sometimes popularly called Planet X or Planet Nine. University of Hawaii's Dave Tholen and Northern Arizona University's Chad Trujillo are also part of the planet search team.
Gareth Williams at the International Astronomical Union's Minor Planet Center used the team's observations to calculate orbits for the newly found moons."It takes several observations to confirm an object actually orbits around Jupiter," Williams said. "So, the whole process took a year."
Nine of the new moons are part of a distant outer swarm of moons that orbit it in the retrograde, or opposite direction of Jupiter's spin rotation. These distant retrograde moons are grouped into at least three distinct orbital groupings and are thought to be the remnants of three once-larger parent bodies that broke apart during collisions with asteroids, comets, or other moons. The newly discovered retrograde moons take about two years to orbit Jupiter.
Two of the new discoveries are part of a closer, inner group of moons that orbit in the prograde, or same direction as the planet's rotation. These inner prograde moons all have similar orbital distances and angles of inclinations around Jupiter and so are thought to also be fragments of a larger moon that was broken apart. These two newly discovered moons take a little less than a year to travel around Jupiter.
"Our other discovery is a real oddball and has an orbit like no other known Jovian moon," Sheppard explained. "It's also likely Jupiter's smallest known moon, being less than one kilometer in diameter".
This new "oddball" moon is more distant and more inclined than the prograde group of moons and takes about one and a half years to orbit Jupiter. So, unlike the closer-in prograde group of moons, this new oddball prograde moon has an orbit that crosses the outer retrograde moons.
As a result, head-on collisions are much more likely to occur between the "oddball" prograde and the retrograde moons, which are moving in opposite directions.
"This is an unstable situation," said Sheppard. "Head-on collisions would quickly break apart and grind the objects down to dust."
It's possible the various orbital moon groupings we see today were formed in the distant past through this exact mechanism.
The team think this small "oddball" prograde moon could be the last-remaining remnant of a once-larger prograde-orbiting moon that formed some of the retrograde moon groupings during past head-on collisions. The name Valetudo has been proposed for it, after the Roman god Jupiter's great-granddaughter, the goddess of health and hygiene.
Elucidating the complex influences that shaped a moon's orbital history can teach scientists about our Solar System's early years.
For example, the discovery that the smallest moons in Jupiter's various orbital groups are still abundant suggests the collisions that created them occurred after the era of planet formation, when the Sun was still surrounded by a rotating disk of gas and dust from which the planets were born.
Because of their sizes--one to three kilometers--these moons are more influenced by surrounding gas and dust. If these raw materials had still been present when Jupiter's first generation of moons collided to form its current clustered groupings of moons, the drag exerted by any remaining gas and dust on the smaller moons would have been sufficient to cause them to spiral inwards toward Jupiter. Their existence shows that they were likely formed after this gas and dust dissipated.
The initial discovery of most of the new moons were made on the Blanco 4-meter telescope at Cerro Tololo Inter-American in Chile and operated by the National Optical Astronomical Observatory of the United States. The telescope recently was upgraded with the Dark Energy Camera, making it a powerful tool for surveying the night sky for faint objects.
Several telescopes were used to confirm the finds, including the 6.5-meter Magellan telescope at Carnegie's Las Campanas Observatory in Chile; the 4-meter Discovery Channel Telescope at Lowell Observatory Arizona (thanks to Audrey Thirouin, Nick Moskovitz and Maxime Devogele); the 8-meter Subaru Telescope and the Univserity of Hawaii 2.2 meter telescope (thanks to Dave Tholen and Dora Fohring at the University of Hawaii); and 8-meter Gemini Telescope in Hawaii (thanks to Director's Discretionary Time to recover Valetudo).
Bob Jacobson and Marina Brozovic at NASA's Jet Propulsion Laboratory confirmed the calculated orbit of the unusual oddball moon in 2017 in order to double check its location prediction during the 2018 recovery observations in order to make sure the new interesting moon was not lost.
"We have found a gas-giant planet that is a virtual twin of a previously known planet, but it looks like the two objects formed in different ways," said Trent Dupuy, astronomer at the Gemini Observatory.
Direct Wircam image of 2MASS 0249 system taken wiht CFHT's infrared camera WIRCam. 2MASS 0249c is located 2000 astronomical units from the host brown dwarfs that are unresolved in this image. Credit: T. Dupuy, M. Liu
When it comes to extrasolar planets, appearances can be deceiving. Astronomers have imaged a new planet, and it appears nearly identical to one of the best studied gas-giant planets. But this doppelgänger differs in one very important way: its origin.
Emerging from stellar nurseries of gas and dust, stars are born like kittens in a litter, in bunches and inevitably wandering away from their birthplace. These litters comprise stars that vary greatly, ranging from tiny runts incapable of generating their own energy (called brown dwarfs) to massive stars that end their lives with supernova explosions.
In the midst of this turmoil, planets form around these new stars. And once the stellar nursery exhausts its gas, the stars (with their planets) leave their birthplace and freely wander the Galaxy. Because of this exodus, astronomers believe there should be planets born at the same time from the same stellar nursery, but orbiting stars that have moved far away from each other over the eons, like long-lost siblings.
"To date, exoplanets found by direct imaging have basically been individuals, each distinct from the other in their appearance and age. Finding two exoplanets with almost identical appearances and yet having formed so differently opens a new window for understanding these objects," said Michael Liu, astronomer at the University of Hawai`i Institute for Astronomy, and a collaborator on this work.
Dupuy, Liu, and their collaborators have identified the first case of such a planetary doppelgänger. One object has long been known: the 13-Jupiter-mass planet beta Pictoris b, one of the first planets discovered by direct imaging, back in 2009. The new object, dubbed 2MASS 0249 c, has the same mass, brightness, and spectrum as beta Pictoris b.
After discovering this object with the Canada-France-Hawaii Telescope (CFHT), Dupuy and collaborators then determined that 2MASS 0249 c and beta Pictoris b were born in the same stellar nursery. On the surface, this makes the two objects not just look-alikes but genuine siblings.
The infrared spectra of 2MASS 0249c and beta Pictoris b are similar, as expected for two objects of comparable mass that formed in the same stellar nursery. Unlike 2MASS 0249c, beta Pictoris b orbits much closer to its massive host star and is imbedded in a bright circumstellar disk. Credit: T. Dupuy, ESO/A.-M. Lagrange et al
However, the planets have vastly different living situations, namely the types of stars they orbit. The host for beta Pictoris b is a star 10 times brighter than the Sun, while 2MASS 0249 c orbits a pair of brown dwarfs that are 2000 times fainter than the Sun. Furthermore, beta Pictoris b is relatively close to its host, about 9 astronomical units (AU, the distance from the Earth to the Sun), while 2MASS 0249 c is 2000 AU from its binary host.
These drastically different arrangements suggest that the planets' upbringings were not at all alike. The traditional picture of gas-giant formation, where planets start as small rocky cores around their host star and grow by accumulating gas from the star's disk, likely created beta Pictoris b. In contrast, the host of 2MASS 0249 c did not have enough of a disk to make a gas giant, so the planet likely formed by directly accumulating gas from the original stellar nursery.
"2MASS 0249 c and beta Pictoris b show us that nature has more than one way to make very similar looking exoplanets," says Kaitlin Kratter, astronomer at the University of Arizona and a collaborator on this work. "beta Pictoris b probably formed like we think most gas giants do, starting from tiny dust grains. In contrast, 2MASS 0249 c looks like an underweight brown dwarf that formed from the collapse of a gas cloud. They're both considered exoplanets, but 2MASS 0249 c illustrates that such a simple classification can obscure a complicated reality."
The team first identified 2MASS 0249 c using images from CFHT, and their repeated observations revealed this object is orbiting at a large distance from its host. The system belongs to the beta Pictoris moving group, a widely dispersed set of stars named for its famous planet-hosting star. The team's observations with the W. M. Keck Telescope determined that the host is actually a closely separated pair of brown dwarfs. So altogether, the 2MASS 0249 system comprises two brown dwarfs and one gas-giant planet. Follow-up spectroscopy of 2MASS 0249 c with the NASA Infrared Telescope Facility and the Astrophysical Research Consortium 3.5-meter Telescope at Apache Point Telescope demonstrated that it shares a remarkable resemblance to beta Pictoris b.
The 2MASS 0249 system is an appealing target for future studies. Most directly imaged planets are very close to their host stars, inhibiting detailed studies of the planets due to the bright light from the stars. In contrast, the very wide separation of 2MASS 0249 c from its host binary will make measurements of properties like its surface weather and composition much easier, leading to a better understanding of the characteristics and origins of gas-giant planets.
The Daily Galaxy via Canada-France-Hawaii Telescope
"While we've learned a lot about ocean viruses in recent decades, we know next to nothing about soil viruses," said Matt Sullivan, a professor of microbiology at Ohio State. "This work's viruses are so novel that they have doubled the total known viruses in the world."
Microbes have significant influence over global warming, primarily through the production of—or consumption of—methane, and new details about these microscopic beings' genetics is now available, thanks to a trio of studies from a project co-led by researchers at The Ohio State University.
"Because of global climate change, huge amounts of permafrost are rapidly warming. To microbes, they're like freezers full of juicy chicken dinners that are thawing out," said Virginia Rich, an assistant professor of microbiology at Ohio State and study author.
"In many cases, microbes take advantage of this situation to chew up what's in the permafrost and breathe out methane. That methane really packs an environmental wallop, with 33 times the climate warming power of carbon dioxide."
Many of these bacterial "consumers" and the viruses that influence them have been identified for the first time in these studies.
While scientists have a clear understanding of the dangers of thawing permafrost for releasing methane, they haven't had a lot of details on the ins and outs of these microbial communities and their contribution to the process.
"The problem is, we don't know all the microbes involved and how they will respond to climate change as the conditions get warmer and wetter, and to do a better job at predicting what will happen in the coming decades we need more information about the key players," Rich said.
Sullivan, senior author on the virus study, said the research is also important because it contributes a great deal to the general understanding of what is happening in soil.
The multinational study was conducted in the portion of Sweden in the Arctic circle, one of the best places in the world to study thawing permafrost because of the rapid changes happening there and because of long-standing and well-documented scientific work in the area, Rich said.
A team of researchers from 10 organizations with expertise in a variety of areas including microbiology, geochemistry and climate modeling are working together in the IsoGenie Project, co-led by Ohio State's Rich, to figure out how they can better predict future climate change based on improved understanding of the connections between microbes and geochemistry.
In these studies, they recovered more than 1,500 microbial genomes in the soil, which was 100 times what was available previously for these habitats. They also found more than 1,900 new viral populations, where none had been previously identified. A genome is the complete set of genes present in an organism.
The researchers were able to link more than a third of the viruses to the microbes they impact. "Now, we have a roadmap from these genomes to be able to understand the roles they play in these communities," Sullivan said.
By looking at the genomes of the microbes, the team was able to figure out what capabilities they have. "It's like now we have not only their fingerprints but also their resumes, to know both who they are and what they are capable of. The next step is figuring out more of what they're actually actively doing out in the field," Rich said.
This is important for several reasons, she said: It will enable climate scientists to better estimate the speed of climate change, giving humans a clearer timetable for response. The study of these rapidly changing habitats also helps the public better appreciate the realities of climate change, Rich said. Furthermore, there might be opportunities for mitigating those effects, including the potential to "fertilize" areas of permafrost to encourage environmentally protective microbial activity, she said.
Not everything about the microbial communities in the permafrost is bad news. Some, called methanotrophs, consume methane in the soil before it gets to the air, which is good for the environment. "As the conditions get warmer and wetter microbes are going to be changing, and some that eat methane may rise up," Rich said.
In February 2001 an eruption from the Surt volcano on the Jupiter-facing hemisphere of Io, the volcanic epi-center of our solar system, occurred with an estimated output of 78,000 Gigawatts. By comparison, the 1992 eruption of Mt Etna, Sicily, was estimated at 12 Gigawatts. During its peak, observed by the WM Keck II Telescope on Hawaii, its output almost matched the eruptive power of all of Io’s active volcanoes combined.
Fast forward to December 2017, data collected by NASA’s Juno spacecraft using its Jovian InfraRed Auroral Mapper (JIRAM) instrument point to a new heat source close to the south pole of Io that could indicate a previously undiscovered volcano on the small moon of Jupiter. The infrared data was collected when Juno was about 290,000 miles (470,000 kilometers) away from the moon.
“The new Io hotspot JIRAM picked up is about 200 miles (300 kilometers) from the nearest previously mapped hotspot,” said Alessandro Mura, a Juno co-investigator from the National Institute for Astrophysics in Rome. “We are not ruling out movement or modification of a previously discovered hot spot, but it is difficult to imagine one could travel such a distance and still be considered the same feature.”
The image above highlights the location of the new heat source close to the south pole of Io. The image was generated from data collected on Dec. 16, 2017, by the Jovian Infrared Auroral Mapper (JIRAM) instrument aboard NASA's Juno mission when the spacecraft was about 290,000 miles (470,000 kilometers) from the Jovian moon. The scale to the right of image depicts of the range of temperatures displayed in the infrared image. Higher recorded temperatures are characterized in brighter colors – lower temperatures in darker colors.
This infrared image of the southern hemisphere of Jupiter’s moon Io was derived from data collected by the Jovian Infrared Auroral Mapper (JIRAM) instrument aboard NASA's Juno spacecraft on Dec. 16, 2017, when the spacecraft was about 290,000 miles (470,000 kilometers) from the Jovian moon.
This annotated image highlights the location of the new heat source in the southern hemisphere of the Jupiter moon Io. The image was generated from data collected on Dec. 16, 2017, by the Jovian Infrared Auroral Mapper (JIRAM) instrument aboard NASA's Juno mission when the spacecraft was about 290,000 miles (470,000 kilometers) from the Jovian moon.
The Juno team will continue to evaluate data collected on the Dec. 16 flyby, as well as JIRAM data that will be collected during future (and even closer) flybys of Io. Past NASA missions of exploration that have visited the Jovian system (Voyagers 1 and 2, Galileo, Cassini and New Horizons), along with ground-based observations, have located over 150 active volcanoes on Io so far. Scientists estimate that about another 250 or so are waiting to be discovered.
Juno has logged nearly 146 million miles (235 million kilometers) since entering Jupiter's orbit on July 4, 2016. Juno's 13th science pass will be on July 16.
Juno launched on Aug. 5, 2011, from Cape Canaveral, Florida. During its mission of exploration, Juno soars low over the planet's cloud tops -- as close as about 2,100 miles (3,400 kilometers). During these flybys, Juno is probing beneath the obscuring cloud cover of Jupiter and studying its auroras to learn more about the planet's origins, structure, atmosphere and magnetosphere.