Tag Archives: Sustain

New modeling studies suggest Titan can only sustain minimal biomass concentrations

Posted on by
Reply

A team of biologists from the US, Canada, UK, and France have developed a scenario for life on Titan, Saturn’s biggest moon.

Rendering of the artist on the surface of Titan, the biggest moon of Saturn. Image credits: Benjamin de Bivort, debivort.org/cc by-sa 3.0.

“Our research focuses on what makes Titan unique when compared to other ice moons and its rich organic content,” said Dr. Antonin Affelder, a researcher at the University of Arizona.

Using bioenergy modeling, Dr. Affholder and colleagues discovered that Titan’s underground ocean, estimated at around 483 km (300 miles), could support life forms that consume organic materials.

“There’s been a lot of speculation about scenarios that could create organisms on Titan based on lunar organic chemistry, but previous estimates suffer from an overly simplified approach,” Dr. Affholder said.

“Because Titan has such abundant organic matter, there was a sense that there was no shortage of food sources that could sustain life.”

“Not all of these organic molecules constitute a food source, and the ocean is really big; there is a limited exchange between the ocean and the surface, and all of those organic matter; so I argue for a more subtle approach.”

At the heart of the study is a fundamental approach that sought to come up with a plausible scenario for Titan’s life, which envisioned one of the simplest and most prominent fermentations of all biological metabolic processes.

Fermentation familiar to earthlings, used in breadmaking, beer brewing, and less desirable – sourdough fermentation, accustomed to its use in the spoilage of forgotten leftovers, requires only organic molecules but no oxidants like oxygen.

“Fermentation probably evolved early in the history of Earth’s life, and there’s no need to open the door to unknown or speculative mechanisms that may or may not have happened on Titan,” Dr. Affholder said.

“Life on Earth may have first appeared to eat organic molecules left behind from the formation of the Earth.”

“I asked if there could be similar microorganisms on Titan. If so, could Titan’s underground seas supply the biosphere from a seemingly vast inventory of abiotic organic molecules synthesized in Titan’s atmosphere, accumulate on its surface, and be present in its core?”

The researchers have focused specifically on glycine, the simplest organic molecule of all known amino acids.

“We know that glycine was relatively abundant in all kinds of primitive matter in the solar system,” Dr. Affholder said.

“When you look at clouds of particles and gases where stars and planets form, like asteroids, comets, our solar system, we find glycine or its precursors in almost every place.”

However, computer simulations reveal that only a small portion of Titan’s organic materials may be suitable for microbial consumption.

The microorganisms consumed by Titan’s ocean glycine rely on a stable supply of amino acids from the surface through thick, ice-like shells.

Previous work by the same team showed that meteors that shock Titan’s ice could leave behind a “melt pool” of liquid water.

“Our new research shows that this supply may be sufficient to maintain very few microorganisms, which are up to a few kilograms of physical fitness.”

“A small biosphere like this is an average of less than one cell per liter in Titan’s vast oceans.”

For your future mission to Titan, the possibility of finding life might be like searching for needles in a haystack if it’s actually there.

“We conclude that Titan’s unique, rich organic inventory may actually not be available to play a role in lunar habitat at an intuitive level of thinking,” Dr. Affholder said.

paper It was published in Journal of Planetary Science.

____

Antonin abholder et al. 2025. Survival rate of glycine fermentation in the underground oceans of Titan. planet. SCI. j 6, 86; doi:10.3847/psj/adbc66

Source: www.sci.news

Research shows active hydrothermal systems on small ocean planets have the potential to sustain life

Posted on by
Reply

Ocean worlds are planetary bodies with liquid oceans, often beneath an icy shell or within rocky interiors. In our solar system, several moons of Jupiter and Saturn are ocean worlds. Some ocean worlds are thought to have hydrothermal circulation, where water, rocks, and heat combine to pump and expel fluids to the ocean floor. Hydrothermal circulation influences the chemical composition of the water and rocks of ocean worlds and may help life develop deep beneath the icy surface. In a new study, planetary researchers used computer simulations of hydrothermal circulation based on well-understood systems on Earth to measure the effects of low gravity at values appropriate for ocean worlds smaller than our home planet. Simulations of ocean worlds with (lower) gravity result in fluid circulation that is roughly similar to that which occurs above and below the ocean floor on Earth, but with some key differences. Low gravity reduces buoyancy, so fluids do not become lighter as they heat up, which reduces their flow rate. This increases the temperature of the circulating fluids, which could lead to more extensive chemical reactions, possibly including those necessary to support life.

This diagram shows how Cassini scientists think rocks and water at the bottom of Enceladus’ ocean interact to produce hydrogen gas. Image courtesy of NASA/JPL-Caltech/Southwest Research Institute.

Rock-heat-fluid systems were discovered on the Earth’s ocean floor in the 1970s, where scientists observed releases of fluids carrying heat, particles, and chemicals.

Many of the vents were surrounded by a novel ecosystem, including specialized bacterial mats, red and white tube worms and heat-sensing shrimp.

For the new study, Professor Andrew Fisher from the University of California, Santa Cruz, and his colleagues used a complex computer model based on the hydrothermal cycle that occurs on Earth.

After varying variables such as gravity, heat, rock properties and depth of fluid circulation, the researchers found that hydrothermal vents could persist under a wide range of conditions.

If these flows occurred on an ocean world like Jupiter’s moon Europa, they could increase the chances of life surviving there as well.

“This study suggests that extraterrestrial ocean worlds may have supported low-temperature (but not hot enough for life) hydrothermal systems on timescales similar to those it took for life to become established on Earth,” Prof Fischer said.

The ocean circulation system on which the researchers based their computer model was discovered on the 3.5-million-year-old seafloor of the northwest Pacific Ocean, east of the Juan de Fuca Ridge.

There, cold undersea water flows through an extinct volcano (seamount), travels about 30 miles (48.3 km) underground, and then flows out into the ocean through another seamount.

“As water flows, it picks up heat, it’s warmer than when it entered, and its chemistry changes dramatically,” says Kristin Dickerson, a doctoral student at the University of California, Santa Cruz.

“The flow from seamount to seamount is driven by buoyancy – as water warms it becomes less dense and as it cools it becomes more dense,” Prof Fischer added.

“The difference in density creates a difference in fluid pressure within the rock, and the system is sustained by the flow itself. So as long as there is enough heat supplied and the rock properties allow for sufficient fluid circulation, the system will keep running. We call this a hydrothermal siphon.”

“Hot vent systems are primarily driven by sub-sea volcanism, while the Earth’s ocean floor experiences large amounts of fluid flowing in and out at much cooler conditions, driven primarily by Earth’s background cooling.”

“The flow of water through low-temperature vents is equivalent to all the rivers and streams on Earth in terms of the volume of water released, and accounts for about a quarter of the Earth’s heat loss.”

“About every 500,000 years, the entire volume of ocean water is pumped up and out of the ocean floor.”

Many previous studies of the hydrothermal circulation on Europa and Enceladus have considered hotter fluids.

“Cartoons and other illustrations often depict undersea systems that are similar to Earth’s black smokers, where cooler currents could occur just as much or even more than they do on Earth,” said Dr Donna Blackman from the University of California, Santa Cruz.

The results show that in very low gravity, such as on the ocean floor of Enceladus, the circulation can continue at low to moderate temperatures for millions or billions of years.

This could help explain why small ocean planets can have long-lived fluid circulation systems beneath their seafloors despite limited heating: the inefficiency of heat extraction could extend their lifetimes considerably, potentially for the entire lifetime of the solar system.

Scientists acknowledge that it is uncertain when active hydrothermal systems will be directly observed on the ocean planet’s seafloor.

The distance from Earth and physical characteristics pose significant technical challenges for spacecraft missions.

“It is therefore essential to make the most of the available data, much of which is remotely collected, and to leverage the understanding gained from decades of detailed study of the analog Earth system,” the authors concluded.

their paper Published in Journal of Geophysical Research: Planets.

_____

A.T. Fisher others2024. Gravitational maintenance of hydrothermal circulation in relation to the ocean world. Journal of Geophysical Research: Planets 129(6):e2023JE008202; doi:10.1029/2023JE008202

Source: www.sci.news

Can ‘iron snow’ potentially sustain life in Europa’s oceans?

Posted on by
Reply

The only example of life in the universe is Earth, a rocky planet with over 70% water on its surface. As far as we know, all life on Earth relies on water to survive and thrive, so scientists refer to other planets where liquid water is known to exist as “habitable.”

But scientists also know that a puddle of water alone is not enough to sustain life. Life depends on a constant flow of electrons between molecules, which Electronic GradientTo create energy, electrons move away from areas of high electron density. Reducelow density areas, so-called Oxidize.

Scientists have found several planets and moons in our solar system that have liquid water. Researchers are particularly intrigued by Jupiter's moon Europa, because remote sensing has revealed that it has a salty liquid ocean about 100 kilometers (60 miles) deep on top of a crust of iron-rich rock, with a layer of ice about 10 kilometers (6 miles) thick on top of that.

Europa has no atmosphere to protect it from the sun's radiation, which allows chemical reactions to take place that consume electrons on its surface, creating an oxidizing environment. In contrast, its iron-rich crust creates a reducing environment beneath its oceans. This means that an electron gradient naturally forms along the path from Europa's oxidizing surface to its reduced ocean floor. Scientists want to know if life could harness this electron gradient to obtain enough energy to sustain itself and survive.

Researchers studying Europa From the data Cassini and Galileo The mission found that Europa's ocean temperatures range from 0 to -13 degrees Celsius, or 32 to 9 degrees Celsius. They found that the hottest temperatures are found closest to the ocean floor, where heat is generated by reactions between water and rock, similar to Earth's hydrothermal systems. They also found that some of the most abundant molecules near Europa's surface are all oxide molecules, such as carbonates and sulfates.

Based on these temperature constraints and the amount of energy provided by oxidizing molecules on Europa's surface, a team of researchers from the University of Akron and the University of Southern California calculated the amount of energy available for life in Europa's ocean and investigated whether three types of Earth microorganisms could live beneath Europa's ocean. The microorganisms they tested generate energy using carbonates, sulfates, or iron particles. They reasoned that because all three of these oxidizing molecules are found on Europa's icy surface, if delivered to the ocean floor, the organisms could combine with reducing molecules on the ocean floor to generate energy.

The researchers calculated that in Europa's environment, molten iron near the surface layer of ice would form solid particles when exposed to penetrating radiation from the sun, and slowly fall to the ocean floor — like snow falling from the sky on Earth, except instead of water ice particles, the ocean rains down in the form of rust-like, reddish iron particles.

The scientists calculated that iron oxide snow would provide a larger electron gradient than carbonates or sulfates, ultimately generating more energy for life. They estimated that iron snow could provide up to 2.5×1026 More than 100 microbial cells are found on Europa's ocean floor per year, which represents about 0.1% of the total number of microbial cells currently living in Earth's oceans.

However, the authors caution that only around 10% of the energy produced by organisms on Earth is used to generate cells — the remaining 90% is used to maintain metabolism, meaning that the number of cells that microbial life could actually generate from Europa's underwater iron pathways would be much lower than the authors estimate.

Nevertheless, the authors suggest that these cell count calculations could be used to design missions to search for life on Europa: When future satellites orbit Europa, researchers could estimate how much cell mass we might expect from microbes living in the iron passages on the Europa ocean floor.


Post View:297

Source: sciworthy.com

Research shows that foxes are less likely to sustain injuries while diving in the snow due to their elongated nose

Posted on by
Reply

Certain fox species dive into the snow to catch prey. This is a hunting mechanism called rat hunting. Red fox (Vulpes Vulpes Vulpes) and arctic fox (Vulpes lagopus) It can dive into the snow at a speed of 2-4m/s. Scientists at Cornell University have found in a new study that a highly curved, elongated snout generates less impact force when it penetrates the snow, reducing the chance of injury in a crash. This skull shape allows the fox to reach deep into the snow, giving it an advantage in catching small rodents at greater depths. As a result, the authors predict that red and arctic foxes living in snow-covered areas will have higher hunting success when hunting mice in the snow.

Yuku other. They studied a hunting technique employed by red foxes and arctic foxes known as mousing. In this hunting technique, they dive headfirst into the snow to capture their prey. Image credit: Yellowstone National Park.

The red fox and the arctic fox dive into the snow to catch their prey. This behavior is known as mouse trapping.

These foxes can locate animals under several feet of snow due to their excellent sensitivity to rustling sounds that peak at frequencies between 2 and 10 kHz.

The fox senses the location of its prey and quickly dives into the snow at 2 to 4 meters per second, catching it completely by surprise.

Previous studies investigated this mouse behavior in terms of diving mechanisms and success rates.

Red foxes tended to jump in a northeast direction, and hunting success was much higher when foxes jumped in this direction compared to all other directions, suggesting that foxes take advantage of the Earth's magnetic field. It was suggested that they were hunting.

However, the mechanical aspects of snow diving, which are also important for hunting success, are not well understood.

“The fox's sharp snout does not compact the snow significantly and penetrates it with little resistance,” said Professor Seong-Hwan Jeong, a researcher in Cornell University's Department of Biological and Environmental Engineering.

In the study, Professor Jung and his colleagues scanned the skulls of foxes and arctic foxes, as well as lynx and puma skulls.

They 3D printed skulls and attached sensors to each to measure impact forces.

The skulls were then dropped into both snow and water, and the researchers fed the data into a computer model to compare the effects of both.

Researchers found that the fox's sharp nose penetrates the snow with little resistance, minimizing potential tissue damage when diving headfirst.

Professor Chong said, “Despite the high-speed impact, snow behaves like water if it is not compressed very much.''

“However, the flattened feline's snout compacted the snow upon impact, creating significant and potentially damaging drag.”

When targeting mice in the snow, the fox's long snout allows it to reach its prey faster, since the mouse is very sensitive to surrounding movements and can quickly escape.

Other behavioral studies have shown that foxes listen for the rustling of mice and other animals beneath the snow by shaking their heads before plunging, thereby gauging the depth of the sound source.

“Although this is a very dangerous process, there have been no reports of foxes being injured,” Professor Chong said.

Regarding this research, paper inside Proceedings of the National Academy of Sciences.

_____

Jisoo Yuk other. 2024. Effects of skull morphology on fox snowdiving. PNAS 121 (19): e2321179121; doi: 10.1073/pnas.2321179121

Source: www.sci.news

Australian Divers Sustain Injuries from Sonar Pulse of Chinese Navy

Posted on by
Reply

The Australian government stated that divers were injured when the Chinese navy used sonar while removing fishing nets underwater.

Australian Defense Minister Richard Marles raised concerns with the Chinese government regarding the “unsafe and unprofessional” use of the technology, following similar complaints from the United States, Canada, and Australia about alleged actions by the Chinese military in the Western Pacific.

Marles mentioned that HMAS Toowoomba was in international waters in Japan’s exclusive economic zone on Tuesday when a fishing net got caught in its propeller and that it supported the United Nations in imposing sanctions on the region.

He described how a PLA-N destroyer (DDG-139) approached HMAS Toowoomba during a dive operation and attached to the hull, causing Australian divers to sustain minor injuries likely due to sonar pulses from the Chinese destroyer.

Sonar uses sound waves to create images of what’s happening underwater. When used at high levels, it can cause dizziness and possibly organ damage.

Use Chrome Browser for a more accessible video player

US Navy Aircraft Carrier Sky News

read more:
Official files on £1.3 billion Royal Navy submarine found inside Wetherspoons pub – Report
Royal Navy helps excavate world’s most remote post office in Antarctica after 4 meters of snow

Opposition politician James Patterson stated that the incident occurred after the prime minister visited China to build closer ties. He mentioned that “While China wants to improve relations with Australia, it is taking dangerous actions that put the safety of Australian personnel at risk,”

China did not immediately respond to the accusation.

Source: news.sky.com