Scientists do not know what is causing the overabundance of the gas.
- A new study looked to understand the source of methane on Saturn's moon Enceladus.
- The scientists used computer models with data from the Cassini spacecraft.
- The explanation could lie in alien organisms or non-biological processes.
Something is producing an overabundance of methane in the ocean hidden under the ice of Saturn's moon Enceladus. A new study analyzed if the source could be an alien life form or some other explanation.
The study, published in Nature Astronomy, was carried out by scientists at the University of Arizona and Paris Sciences & Lettres University, who looked at composition data from the water plumes erupting on Enceladus.
The particular chemistry, discovered by the Cassini spacecraft which flew through the plumes, suggested a high concentration of molecules that have been linked to hydrothermal vents on the bottom of Earth's oceans. Such vents are potential cradles of life on Earth, according to previous studies. The data from Cassini, which has been studying Saturn after entering its orbit in 2004, revealed the presence of molecular hydrogen (dihydrogen), methane, and carbon dioxide, with the amount of methane presenting a particular interest to the scientists."We wanted to know: Could Earthlike microbes that 'eat' the dihydrogen and produce methane explain the surprisingly large amount of methane detected by Cassini?" shared one of the study's lead authors Régis Ferrière, an associate professor in the department of Ecology and Evolutionary Biology at the University of Arizona.
Earth's hydrothermal vents feature microorganisms that use dihydrogen for energy, creating methane from carbon dioxide via the process of methanogenesis.
Searching for such microorganisms known as methanogens on the seafloor of Enceladus is not yet feasible. Likely, it would require very sophisticated deep diving operations that will be the objective of future missions.
So, Ferrière's team took a more available approach to pinpointing the origins of the methane, creating mathematical models that attempted to explain the Cassini data. They wanted to calculate the likelihood that particular processes were responsible for producing the amount of methane observed. For example, is the methane more likely the result of biological or non-biological processes?
They found that the data from Cassini was consistent with either microbial activity at hydrothermal vents or processes that have nothing to do with life but could be quite different from what happens on Earth. Intriguingly, models that didn't involve biological entities didn't seem to produce enough of the gas.
"Obviously, we are not concluding that life exists in Enceladus' ocean," Ferrière stated. "Rather, we wanted to understand how likely it would be that Enceladus' hydrothermal vents could be habitable to Earthlike microorganisms. Very likely, the Cassini data tell us, according to our models."
Still, the scientists think future missions are necessary to either prove or discard the "life hypothesis." One explanation for the methane that does not involve biological organisms is that the gas is the result of a chemical breakdown of primordial organic matter within Enceladus' core. This matter could have become a part of Saturn's moon from comets rich in organic materials.
Strange underwater icicles form in the Earth's coldest regions and freeze living organisms in place.
- Spectacular brinicles form under the ice of our planet's coldest regions.
- Their formation resembles that of hydrothermal vents.
- The structures have been called "icy fingers of death" because of their ability to freeze living organisms.
Nature's grace and fury find equal measure in unique formations called brinicles or more evocatively "icy fingers of death." The strange phenomenon that forms these underwater icicles can be found in the oceans of the planet's polar regions. It's been rarely captured on camera as it occurs under floating sea ice. Brinicles are structures that resemble fingers of ice that can reach all the way down to the ocean floor, freezing everything in their paths, including creatures like starfish or sea urchins.
In an interview with Wired, professor Andrew Thurber of Oregon State University, who has seen brinicles first-hand, described them as "upside-down cacti that are blown from glass, like something from Dr. Seuss's imagination." He also said they are "incredibly delicate and can break with only the slightest touch."
The video below shows stunning footage of brinicles from BBC's Frozen Planet series:
'Brinicle' ice finger of death
How brinicles form
A study found that when sea ice in the Arctic and Antarctic regions freezes, salt and other ions normally found in seawater get left out. Brine, which is concentrated salt water, gathers in various fractures and channels in the sea ice. Brine requires much lower temperatures to freeze and stays liquid until the ice cracks and the brine leaks into the ocean below. Being heavier than water, the ultra-cold brine sinks down to the ocean floor, freezing seawater it touches on its way down. This is responsible for the finger-like shape of the brinicles.
Notably, the downward-facing brinicle ice tubes, first discovered in the 1960s, form in a way similar to hydrothermal vents, which have been theorized as cradles of life on Earth. Hydrothermal vents form when ion-rich hot water gets ejected from the seafloor, creating a porous metal tower that extends upward. Water rushes through the tower, rupturing it, and causing more metal-rich water to expand the tower.
Thousands of brinicles can be found under the ice off Little Razorback Island, Antarctica.Credit: Andrew Thurber / Oregon State University.
Could brinicles be cradles of life?
Study author Bruno Escribano of the Basque Center for Applied Mathematics in Spain explained that, like hydrothermal vents, brinicles also could have played a role in the origin of life. "Inside these compartments inside the ice, you have a high concentration of chemical compounds, and you also have lipids, fats, that coat the inside of the compartment," he shared. "These can act as a primitive membrane — one of the conditions necessary for life."
He elaborated that inside the brinicles is a mixture of acidic and basic components that may be able to supply the requisite energy for the formation of more complex molecules, potentially even DNA.
A new study reveals what caused most life on Earth to die out during the end-Permian extinction, also known as the Great Dying.
- A new paper claims to identify the cause of the Great Dying that occured nearly 252 million years ago.
- During the worst mass extinction event ever, most of Earth's life perished.
- The study suggests a volcanic eruption in Siberia spread aerosolized nickel particles that harmed organisms on the planet.
Dinosaurs are the most infamous victims of a mass extinction event 66 million years ago. But an even worse extinction happened 251.9 million years ago.
Called the end-Permian mass extinction or the Great Dying, this most severe of extinction events wiped out about 90 percent of the planet's marine species and 75 percent of terrestrial species. While scientists long have suspected it was initiated by volcanic eruptions in what is now Siberia, until now they haven't been able to explain exactly how so many species died out.
A new paper published in Nature Communications lays out the case that nickel particles that became aerosolized as a result of eruptions in the Siberian Traps region became dispersed through the air and water and were the cause of the ensuing environmental catastrophe. The paper pinpoints huge Norilsk nickel sulfide ore deposits in the Tunguska Basin that "may have released voluminous nickel-rich volcanic gas and aerosols into the atmosphere" as the start of the chain of events that led to the mass extinction.
The study is based on analysis of nickel isotopes that came from late Permian sedimentary rocks gathered from the Buchanan Lake section in the Sverdrup Basin in the Canadian High Arctic. What's notable about the rock samples is that they featured the lightest nickel isotope ratios ever measured, leading the scientists to conclude that the nickel came in the form of aerosolized particles from a volcano.
As the paper outlines, the only comparable nickel isotope values would be those from volcanic nickel sulfide deposits. The scientists write that of all the mechanisms that could result in such values, "the most convincing" explanation is that they got there as "voluminous Ni-rich aerosols" from the Siberian Traps large igneous province (STLIP).
The deadly effect of nickel particles
When the nickel got into the water, it wreaked havoc on the underwater ecosystem.
Co-author of the study, associate professor Laura Wasylenki of Northern Arizona University, explained that "nickel is an essential trace metal for many organisms, but an increase in nickel abundance would have driven an unusual surge in productivity of methanogens, microorganisms that produce methane gas. Increased methane would have been tremendously harmful to all oxygen-dependent life." This would have affected living creatures in and out of the water. The professor believes their data offers direct evidence that links nickel-rich aerosols, changes to the ocean, and the mass extinction that followed. "Now we have evidence of a specific kill mechanism," she added.
NAU associate professor Laura Wasylenki.Credit: Northern Arizona University.
Other theories on the Great Dying
Previous studies have pointed to other effects of the Siberian volcanic eruptions that likely contributed to the extinction event, including an overall warming of the planet, release of toxic metals, and acidification of the oceans, which likely killed off a number of species quickly. Others died out as a result of the depleted oxygen levels in the water.
"This domino-like collapse of the inter-connected life-sustaining cycles and processes ultimately led to the observed catastrophic extent of mass extinction at the Permian-Triassic boundary," said marine biogeochemist Hana Jurikova of the University of St. Andrews in the UK, who carried out a 2020 study on the end-Permian extinction. Her study looked at fossil shells from brachiopods in what is now the Southern Alps in Italy.
A new study finds an unusual genetic difference in people over 105.
- Researchers conduct genetic analyses of 81 Italian people who are over 105 years in age.
- Five unusual genetic differences were discovered.
- The differences are implicated in the routine repair of DNA, which seems to work unusually well in these people.
The oldest living person is Kane Tanaka of Fukuoka, Japan, who just celebrated her 116th birthday. The handful of people who live to be 105 years old or older are called "semi-supercentenarians." (Supercentenarians live to the ripe old age of 110 or older.)
New research, published in the Aging, Geroscience and Longevity: A Special Issue of the journal eLife, examines the genomes of semi-supercentenarians and has discovered what may be the key to their unusually long lives: Their DNA is exceptionally good at repairing itself.
People involved in the study
Men play cards in Martina Franca, ItalyCredit: sabino.parente via Adobe Stock
The researchers recruited 81 volunteers for genetic analysis from across Italy. Some participants were semi-supercentenarians and others were supercentenarians. Researchers compared the genetic makeup of the older volunteers with those of 36 healthy people from the same areas who were 68 years old, plus or minus 5.9 years.
"Aging is a common risk factor for several chronic diseases and conditions. We chose to study the genetics of a group of people who lived beyond 105 years old and compare them with a group of younger adults from the same area in Italy, as people in this younger age group tend to avoid many age-related diseases and therefore represent the best example of healthy aging."
The authors of the study collected blood samples from both groups and conducted whole-genome sequencing. Additionally, they compared their findings with the conclusions drawn in previously published research describing the genetic makeup of 333 Italian people older than 100 years and 358 who were approximately 60 years old.
Co-first author of the new research Massimo Delledonne of the University of Verona said, "This study constitutes the first whole-genome sequencing of extreme longevity at high coverage that allowed us to look at both inherited and naturally occurring genetic changes in older people."
It's all in the genes
In the semi-supercentenarians and some supercentenarians, the researchers discovered five unusual genetic changes that were often present in two genes, COA1 and STK17A, data that was consistent with the previous research.
Most intriguing, the genetic variations appear to be linked to increased activity of the STK17A gene in some tissues, a gene involved in three critical cell repair activities: managing cells' response to DNA damage, prompting badly damaged cells to die off, and controlling the amount of dangerous reactive oxygen species in a cell. Cells unable to perform these types of repair activities are more likely to become cancerous.
The COA1 gene is involved with energy production by promoting communication between the cell nucleus and mitochondria. The researchers believe that the genetic variants they detected reduce the level of COA1 activity, which in turn reduces energy production as well as aging. (One of the leading theories of aging is that energy production produces reactive oxygen species that damage cells and promote aging.)
Finally, the researchers noted that the genetic variants they identified are also linked to increased expression of he BLVRA gene in some tissue. This gene is also involved in the elimination of dangerous reactive oxygen species.
"Our results suggest that DNA repair mechanisms and a low burden of mutations in specific genes are two central mechanisms that have protected people who have reached extreme longevity from age-related diseases."
The retraction crisis has morphed into a citation crisis.
- Even after scientific papers are retracted, hundreds of studies cite them as evidence.
- Roughly four retractions occur per 10,000 publications, mostly in medicine, life sciences, and chemistry journals.
- Journals should implement control measures that block the publication of papers that cite retracted papers.
Andrew Wakefield's 1998 study linking vaccines with autism was riddled with holes. All 12 children involved were handpicked, which is antithetical to clinical research. The now-deregistered physician falsified results. Wakefield used microscopic-level stains to make his case; a more reliable molecular method found no evidence of a link between vaccines and autism.
Add to this the fact that parents of study subjects, some with their own agendas (such as litigation), kept changing the timeline of their child's conditions. During all this time when Wakefield was raging against the vaccine, he filed for two patents on single measles shots. It was a money play from day one.
Twenty-three years later, the vaccine-autism myth remains in circulation despite decades of contrary evidence. Six years after the study was published, 10 of the 13 authors of their paper retracted their findings. It took The Lancet a few more years; in 2010 the publication finally retracted the paper. Journalist Brian Deer documented Wakefield's scam for years. Still, the lie persists.Science's replication crisis is well-known. But the research community is suffering from another serious problem, one ill-fated for the social media age: the retraction crisis.
Will America’s disregard for science be the end of its reign? | Big Think
As science journalist (and former marine biologist) Fanni Daniella Szakal recently pointed out, retracted papers are still being cited and used as gospel even when—sometimes it seems especially when—data are intentionally fabricated. Currently, roughly four retractions occur per 10,000 publications, with the highest percentages being in medicine, life sciences, and chemistry journals.
That overall number might not seem high yet those retracted studies have an outsized influence. Wakefield claiming the MMR vaccine causes autism as a ruse to patent his own vaccine is the most infamous example, but there are others.
- A 2005 paper touting omega-3 polyunsaturated fatty acids as having anti-inflammatory effects was retracted in 2008 after it was discovered that one author intentionally falsified data. After 2008, however, 96 percent of papers that cited the study never mentioned that it had been retracted.
- German anesthesiologist Joachim Boldt has a whopping 103 retractions credited to his name. Considered the greatest fraud in medicine since Wakefield, his studies, including influential work on the role of hydroxyethyl starch, continues to be cited today.
- Two COVID-19 studies published in reputable journals were retracted after their findings were deemed to be suspect. The researchers relied on a combination of big data and AI to replace randomized controlled clinical trials, leading to false results. Still, the retracted papers were cited in other prestigious journals and have been, in part, seized upon by anti-vaxxers that point to a nefarious medical industry trying to confuse us with conflicting evidence.
Gastroenterologist Dr Andrew Wakefield arrives with his wife Carmel flanked by supporters on July 16, 2007 in London, England.
As Szakal notes, a solid grasp of science matters considering research drives policy and healthcare decisions. We can't possibly expect every paper to get it right, but unfortunately, we also have to factor in biased researchers pushing forward their agendas. While the publication of such research is troublesome, Szakal takes particular issue with the authors and publications that continue to cite them after they've been retracted.
More than just a critique, however, Szakal suggests a path forward.
"In each and every publication, author guidelines should include that the author is needed to check all citations for possible retractions. Today numerous citation software are available to do this with ease; such as Zotero, scite.ai, and RedacTek alert users for any retracted papers in the reference list. As well as more care from authors, preventing post-retraction citations is a responsibility of publishers too. Along with double-checking the reference list of papers to be published, they should also make sure that retraction notices appear on all platforms where the study is available."
The past year has proven how dangerous scientific misinformation (and, even more disturbingly, disinformation) is to public health measures. The frantic urgency of social media platforms and the speed with which we consume headlines without reading articles makes teaching good science even more daunting. At the very least, we need the gatekeepers to take more responsibility for their publication process. Being the first to break bad science is way more socially damaging than being the tenth to publish science worth repeating.
Stay in touch with Derek on Twitter and Facebook. His most recent book is "Hero's Dose: The Case For Psychedelics in Ritual and Therapy."