Excellent New Astronomy: James Webb Space Telescope finds water in super-hot exoplanet’s atmosphere

[This telescope is finding amazing stuff in space. Jan]

The atmosphere of the exoplanet WASP-18 b reaches nearly 5,000 degrees Fahrenheit (2,700 degrees Celsius).

The James Webb Space Telescope has found traces of water vapor in the atmosphere of a super-hot gas giant exoplanet that orbits its star in less than one Earth day.

The exoplanet in question, WASP-18 b, is a gas giant 10 times more massive than the solar system’s largest planet, Jupiter. The planet is quite extreme, as it orbits the sun-like star WASP-18, which is located some 400 light-years away from Earth, at an average distance of just 1.9 million miles (3.1 million kilometers). For comparison, the solar system’s innermost planet, Mercury, circles the sun at a distance of 39.4 million miles (63.4 million km).

Due to such close proximity to the parent star, the temperatures in WASP-18 b’s atmosphere are so high that most water molecules break apart, NASA said in a statement. The fact that Webb managed to resolve signatures of the residual water is a testament to the telescope’s observing powers.

"The spectrum of the planet’s atmosphere clearly shows multiple small but precisely measured water features, present despite the extreme temperatures of almost 5,000 degrees Fahrenheit (2,700 degrees Celsius)," NASA wrote in the statement. "It’s so hot that it would tear most water molecules apart, so still seeing its presence speaks to Webb’s extraordinary sensitivity to detect remaining water."

WASP-18 b, discovered in 2008, has been studied by other telescopes, including the Hubble Space Telescope, NASA’s X-ray space telescope Chandra, the exoplanet hunter TESS and the now-retired infrared Spitzer Space Telescope. None of these space telescopes, however, was sensitive enough to see the signatures of water in the planet’s atmosphere.

"Because the water features in this spectrum are so subtle, they were difficult to identify in previous observations," Anjali Piette, a postdoctoral fellow at the Carnegie Institution for Science and one of the authors of the new research, said in the statement. "That made it really exciting to finally see water features with these JWST observations."

In addition to being so massive, hot and close to its parent star, WASP-18 b is also tidally locked. That means one side of the planet constantly faces the star, just like the moon’s near side always faces Earth. As a result of this tidal locking, considerable differences in temperature exist across the planet’s surface. The Webb measurements, for the first time, enabled scientists to map these differences in detail.

The James Webb Space Telescope detected traces of water in the super hot atmosphere of exoplanet WASP-18 b

The measurements found that the most intensely illuminated parts of the planet can be up to 2,000 degrees F (1,100 degrees C) hotter than those in the twilight zone. The scientists didn’t expect such significant temperature differences and now think that there must be some not yet understood mechanism in action that prevents the distribution of heat around the planet’s globe.

"The brightness map of WASP-18 b shows a lack of east-west winds that is best matched by models with atmospheric drag," co-author Ryan Challener, of the University of Michigan, said in the statement. "One possible explanation is that this planet has a strong magnetic field, which would be an exciting discovery!"

To create the temperature map, the researchers calculated the planet’s infrared glow by measuring the difference in the glow of the parent star during the time the planet transited in front of the star’s disk and then when it disappeared behind it.

"JWST is giving us the sensitivity to make much more detailed maps of hot giant planets like WASP-18 b than ever before," Megan Mansfield, a Sagan Fellow at the University of Arizona and one of the authors of the paper describing the results. said in the statement. "This is the first time a planet has been mapped with JWST, and it’s really exciting to see that some of what our models predicted, such as a sharp drop in temperature away from the point on the planet directly facing the star, is actually seen in the data."

The new study was published online Wednesday (May 31) in the journal Nature.

Source: https://www.space.com/james-webb-water-atmosphere-hot-jupiter-exoplanet-wasp-18b

Genetic Science: This tiny fern has the largest genome of any organism on Earth

In a new study published in the journal iScience, researchers from the Royal Botanic Gardens, Kew and the Institut Botànic de Barcelona (IBB-CSIC) in Spain present a new record-holder for the largest amount of DNA stored in the nucleus of any living organism on the planet.

Coming in at more than 100 meters of unraveled DNA, the New Caledonian fork fern species Tmesipteris oblanceolata was found to contain more than 50 times more DNA than humans and has dethroned the Japanese flowering plant species Paris japonica, which has held this record since 2010.

In addition, the plant has achieved three Guinness World Records titles for Largest plant genome, Largest Genome, and Largest fern genome for the amount of DNA in the nucleus.

T. oblanceolata is a rare species of fern found on the island nation of New Caledonia, an overseas French territory situated in the Southwest Pacific, about 750 miles east of Australia, and some of the neighboring islands such as Vanuatu. The genus Tmesipteris is an understudied group of plants consisting of about 15 species, most of which occur across a range of Pacific Islands and Oceania.

Until now, scientists have only estimated the size of the genomes for two species of Tmesipteris—T. tannensis and T. obliqua—both of which were found to contain gigantic genomes, at 73.19 and 147.29 gigabase pairs (Gbp) respectively.

In 2023, lead authors Dr. Jaume Pellicer and Dr. Oriane Hidalgo, from the IBB and formerly of RBG Kew, traveled to New Caledonia to collect samples of Tmesipteris, which were then analyzed to estimate the size of their genomes. This involved isolating the nuclei of thousands of cells, staining them with a dye and then measuring how much dye had bound to the DNA within each nucleus—the more dye, the bigger the genome.

The previous record holder for the world’s largest genome was the flowering plant, Paris Japonica at 148.89 gigabase pairs. Credit: RBG Kew
The analysis revealed the species T. oblanceolata to have a record-breaking genome size of 160.45 Gbp, which is about 7% larger than that of P. japonica (148.89 Gbp).

When unraveled, the DNA from each cell of this fern would stand taller than the Elizabeth Tower in Westminster, London, which is 96m tall and home to the world-famous Big Ben bell. For comparison, the human genome contains about 3.1 Gbp distributed across 23 chromosomes and when stretched out like a ball of yarn, the length of DNA in each cell only measures about 2m.

Dr. Pellicer, a researcher in evolutionary biology, says, "Tmesipteris is a unique and fascinating small genus of ferns, whose ancestors evolved about 350 million years ago—well before dinosaurs set foot on Earth—and it is distinguished by its mainly epiphytic habit [it grows mainly on the trunks and branches of trees] and restricted distribution in Oceania and several Pacific Islands.

"For a long time, we thought that breaking the previous size record of Paris japonica was going to be an impossible mission, but once again, the limits of biology have surpassed our most optimistic predictions.

"Based on our previous research, we anticipated the existence of giant genomes in Tmesipteris. That said, discovering the largest genome of them all is not just a feat of scientific exploration, but the result of an almost fourteen-year journey into the boundless complexity and diversity of plant genomes."

To date, scientists across the globe have estimated the genome sizes of more than 20,000 eukaryotic organisms, revealing in the process a wide range of genome sizes across the tree of life. These, in turn, have been found to have a profound impact not only on their anatomy, as bigger genomes need bigger cells to house them and take longer to replicate, but also how they function, evolve, and where and how they live.

The DNA of T. oblanceolata measures over 106m in length, making it taller than Elizabeth Tower in London, home to Big Ben. Credit: Pol Fernandez
In animals, some of the largest genomes include the marbled lungfish (Protopterus aethiopicus) at 129.90 Gbp and the Neuse River waterdog (Necturus lewisi) at 117.47 Gbp. In stark contrast, six of the largest-known eukaryotic genomes are held by plants, including the European mistletoe (Viscum album) at 100.84 Gbp.

Surprisingly, having a larger genome is usually not an advantage. In the case of plants, species possessing large amounts of DNA are restricted to being slow growing perennials, are less efficient at photosynthesis (the process by which plants convert the sun’s energy into sugars) and require more nutrients (especially nitrogen and phosphates) to grow and compete successfully with their smaller-genomed neighbors. In turn, such effects may influence the ability of a plant to adapt to climate change and their risk of extinction.

Dr. Ilia Leitch, Senior Research Leader—Character Evolution, at RBG Kew, says, "Who would have thought this tiny, unassuming plant that most people would likely walk past without notice, could bear a world-beating record in genome size.

"Compared to other organisms, plants are incredibly diverse when viewed at the DNA level, and that should make us pause to think about their intrinsic value in the wider picture of global biodiversity. This discovery also raises many new and exciting questions about the upper limits of what is biologically possible, and we hope to solve these mysteries one day."

Adam Millward, Managing Editor of Guinness World Records, says, "To think this innocuous-looking fern boasts 50 times more DNA than humans is a humbling reminder that there’s still so much about the plant kingdom we don’t know, and that record holders aren’t always the showiest on the outside."

More information: Oriane Hidalgo and Jaume Pellicer et al, A 160 Gbp fork fern genome shatters size record for eukaryotes. iScience (2024). DOI: 10.1016/j.isci.2024.109889

Journal information: iScience

Source: https://phys.org/news/2024-05-tiny-fern-largest-genome-earth.html

Science & Technology: Building an AIRCRAFT to fly on Mars! – Future Mars plane could help solve Red Planet methane mystery (exclusive)

[The idea of flying aircraft on Mars is awesome. And having a solar powered plane is awesome. I think this is awesome in the light of the amazing success of the little helicopter. Click on the source link to see a picture of what they are thinking of. Jan]

MAGGIE, an early-stage concept at the moment, could search for elusive traces of life in the Martian atmosphere.

Mars methane is hard to trace, but a solution might be on the way.

An early-stage airplane concept called MAGGIE will soon kick off a nine-month NASA-funded study to explore its feasibility for soaring over Mars. It won’t go to the Red Planet any time soon, if ever, but there’s a clear science need for more flying vehicles on Mars.

NASA’s Ingenuity helicopter, the first heavier-than-air vehicle to soar on Mars, finished 72 flights after arriving with the Perseverance rover in February 2021. While Ingenuity had a hard landing in January 2024 that grounded it for good, there’s plenty of room for more flying vehicles in the future.

MAGGIE — short for "Mars Aerial and Ground Intelligent Explorer" — is designed to operate for a Martian year (nearly two Earth years) anywhere around the Red Planet. Flying 3,300 feet (1,000 meters) above the surface, one of its prime missions could be finding methane. That elusive molecule could be a sign of life, but scientists have had little luck figuring out its presence in the Martian atmosphere after decades of searching.

Methane, a possible biosignature gas, has been hard to find on Mars. It pops up now and again in the atmosphere, detectable by spacecraft on or orbiting the Red Planet or by powerful telescopes here on Earth. NASA’s long-running Curiosity rover mission (ancestor to Perseverance), for example, has repeatedly detected methane since 2012, but the levels go up and down — a background level of less than 0.5 parts per billion (ppb) molecules of air, sometimes spiking up to 20 ppb.

The next logical step could be a flying vehicle like MAGGIE, principal investigator Gecheng Zha told Space.com. Zha is CEO of Coflow Jet and a professor at the University of Miami who received nine months of funding under the NASA Innovative Advanced Concepts (NIAC) program to explore this concept further.

MAGGIE could stay in the air for a distance of 111 miles (179 km), its design suggests, on a single charge of its solar panels. Zha says high-resolution instruments on board could pick out trace amounts of methane in the atmosphere, or other potential transient phenomena like liquid water on Mars. Better yet, "we can also land in any place we’d like to get samples," he told Space.com.

An image of NASA’s Curiosity rover on Mars composed of 57 separate photographs the rover took on May 12, 2019. Curiosity has found transient signals of methane on Mars. (Image credit: NASA/JPL-Caltech/MSSS)
MAGGIE’s presumed range comes courtesy of patented technology that would use air compressors to keep the aircraft aloft. The air compressors move small amounts of atmosphere from the back of the wings toward the front, both increasing lift and reducing drag.

This process would allow MAGGIE to be flexible for different temperatures and pressures of atmosphere, allowing it to navigate the thin air of Mars during different seasons and at different latitudes, particularly during challenging seasons like winter. Normally, the Martian atmosphere’s pressure is between 6 and 10 millibars, just one one-hundredth of Earth’s surface pressure, according to NASA. And during the cold season, roughly 25% of the atmosphere condenses on the polar caps, causing a further plunge in Red Planet pressure.

Before reaching Mars, MAGGIE must meet the major goal of its NIAC phase 1 study, which is to determine if the airplane could indeed work in the thin atmosphere of Mars. "We’ll do more vehicle design and a feasibility study, and we will also do the science mission," Zha said, emphasizing that partners such as NASA’s Jet Propulsion Laboratory in Southern California will also be involved on the science side.

Next up, if the initial MAGGIE study goes well, will be inclusion in the two-year phase 2 of NIAC to deepen the engineering and science work. A range of investigations could fly on the mission, such as examining the strange magnetic field of Mars, or photographing surface features in high definition, depending on the priority.

Zha has been working on the idea behind MAGGIE for more than 20 years, mostly on the engineering side. He received several grants before this one, too, including NASA funding for a type of jet flow control, and the Defense Advanced Research Projects Agency (DARPA) Award for Aviation Transports.

He was glad to see Ingenuity take flight in the interim: "When we saw the Ingenuity helicopter flying, it was very, very exciting and inspiring." And he’s looking forward to other Martian explorers taking to the skies as soon as feasible.

That could happen relatively quickly, pending ongoing troubles with funding for NASA’s Mars Sample Return program. The current concept suggests two helicopter fetchers could ride along with the return mission in the 2030s that would bring caches back from the surface, which were collected by Perseverance.

Source: https://www.space.com/mars-plane-maggie-methane-mystery?utm_term=AF536F6D-055D-443A-91F7-FD448D0CCA73&lrh=4cd1bd23c622eeb1274411ac3b55b43215b8c098a20f14a3285c9e8ae13a98ca&utm_campaign=58E4DE65-C57F-4CD3-9A5A-609994E2C5A9&utm_medium=email&utm_content=6AD8A50B-E4AE-4815-85A1-964FD3002E5F&utm_source=SmartBrief

Mysterious ‘painted people’ of Scotland are long gone, but their DNA lives on

Ancient DNA reveals that the Picts, the "painted people" of Scotland who fought off the Romans, weren’t an enigmatic group that migrated from faraway lands. Instead, the Picts had local roots and were related to other Iron Age people in Britain, a new study finds.

An analysis of eight skeletons from two Pictish cemeteries, published Thursday (April 27) in the journal PLOS Genetics, also suggests that the Picts did not organize their society around the female bloodline, contrary to what historians have long suggested.

The Picts, named from the Latin word "picti" for their reported use of body paint or tattoos, were a people who, in the third century A.D., resisted Roman rule and formed their own kingdom in northern Britain that lasted until around A.D. 900. There is very little written information about the Picts — much of what they wrote is in a unique and hard-to-translate script called ogham — and only a few of their settlements and cemeteries have been found.

The general lack of sources about the Picts and their way of life has led to numerous assumptions over the centuries. In the eighth century, during the early medieval period, for example, historians such as the Venerable Bede thought that the Picts emigrated from areas around the Aegean Sea or Eastern Europe and that they traced descent matrilineally, through the mother’s side.

Archaeologists and historians have begun to tackle the "Pictish problem" in recent years, however, to develop a better understanding of this culture.

In the newly published study, an international team of researchers extracted genetic information from eight human skeletons buried in two Pictish cemeteries — seven from Lundin Links and one from Balintore in modern-day Scotland.

"Lundin Links is one of the few excavated and well-dated monumental cemeteries from the Early Medieval (Pictish) period in Scotland," study co-author Linus Girdland Flink, an archaeogeneticist at the University of Aberdeen, told Live Science in an email. According to past research, the cemetery dates to A.D. 450 to 650 and holds the remains of a couple dozen people.

Human remains from the Pictish period are scarce, but the sandy soils at Lundin Links are more conducive to long-term preservation because they are less acidic than soil in other areas of Scotland. "This suggested to us that DNA may also be preserved and prompted further investigation," Girdland Flink said.

The team was able to extract a nearly complete genome, or set of a person’s genes, from one skeleton from each of the two cemeteries. Both genomes, when compared with those of other ancient and modern groups from the British Isles, "reveal a close genetic affinity to Iron Age populations from Britain," the researchers wrote in the study, but show differences as well that are likely related to migration events and intermarriage with other groups.

From all seven Lundin Links skeletons, researchers were able to isolate mitochondrial DNA (mtDNA) information, which is passed from mother to child, allowing them to look into the assumption about matrilineal Picts. But none of the people whose mtDNA they analyzed shared immediate maternal ancestors, which means they "were unlikely to have been practicing matrilocality," according to the study.

The team also found that the Picts’ genes persist in modern-day people who live in western Scotland, Wales, Northern Ireland and Northumbria (a medieval kingdom that now includes parts of northern England and southeastern Scotland), indicating that, even though their culture disappeared, their genes didn’t.

"This paper is a welcome and overdue addition of Scottish samples to the growing literature on the paleogenetic study of the early medieval period," Adrián Maldonado, a research fellow at National Museums Scotland who was not involved in the study, told Live Science in an email. "It is more evidence that the inhabitants of north-eastern Scotland were not some shadowy relic population, untouched by time."

It’s a limitation that the study presents just two genomes from individuals in cemeteries 100 miles (160 kilometers) apart, Maldonado noted, but it’s still a helpful step forward. "I eagerly await a larger dataset, including not just ‘Picts’ but their neighbors and descendants in later centuries, preferably joined with other proxies for mobility from stable isotope analysis," he said. "Only then will we have a clearer picture of the transformation of society in these critical post-Roman centuries."

Additional research on Pictish Scotland is already underway, according to a statement by study first author Adeline Morez, who completed the work while at Liverpool John Moores University and is now a postdoctoral researcher at the French National Center for Scientific Research (CNRS), including excavation of new sites, chemical analysis of dietary habits and migration, and further DNA work.

Source: https://www.livescience.com/archaeology/mysterious-painted-people-of-scotland-are-long-gone-but-their-dna-lives-on