Colorful Hot Springs

The iconic image of Yellowstone is an expansive spring with rainbow-like colors radiating from its center, dominated by a fiery orange hue at its edges. Though these dazzlingly painted hot springs seem fit only for picture books, their colors come from very real, and very earthly, microscopic creatures.

Hiding out in the park’s hot springs — where temperatures are high enough to blister your skin and as acidic as liquid in a car battery — are heat-loving microbes. And they’re thriving. Where you see rings of color, there are, most of the time, rings of different bacteria, each group adapted to the conditions, such as temperature and pH (how acidic a solution is) of their environments, according to the National Park Service.

Take Grand Prismatic Spring, the park’s largest hot spring and the one whose rainbow colors make it so iconic. Its diverse hues can be explained by the ways temperature and light affect microbes.

Let’s start at the center of the hot spring, a brilliant aquamarine. The center of the spring is just above its underground water source, and it’s where temperatures are the highest — up to 189 degrees Fahrenheit (or 87 degrees Celsius), Smithsonian reported. There, the water is too hot for most microbial growth. It is, therefore, mostly clear water. The center of the spring is blue for the same reason that the sky is blue: When sunlight hits the water’s surface, the light scatters, and blue light scatters the most, meaning that’s what reflects back to your eyes.

The hot spring’s water cools as it spreads farther from the source, and that, in turn, changes the bacteria that can live in it.

Moving outward from the blue center, the first ring of color is yellow, thanks to cyanobacteria called Synechococcus. The temperature of this yellow band is about 165 degrees F (74 degrees C). Under other conditions, these bacteria might create a blue-green hue thanks to chlorophyll, a green pigment they produce that allows them to photosynthesize, or build carbohydrates and oxygen gas out of water, carbon dioxide, and energy from the sun, during the day, according to the National Park Service. (At night, they switch to another mode of energy production, fermentation.) But the sunlight hitting the prismatic spring is so intense that the bacteria produce another kind of pigment called carotenoids, which act as sunscreen for the bacteria, according to the Smithsonian magazine. Carotenoids, which are also found in carrots, are orange and thus turn the normally green Synechococcus bacteria a more jaundiced shade.

In the orange band, which is a cooler 149 degrees F (65 degrees C), you’d find not only Synechococcus bacteria but also Chloroflexus bacteria, which also contain both chlorophyll, for photosynthesis, and the carrot-colored carotenoids. Two other bacteria that produce orange-colored mats, Phormidium and Oscillatoria, which are both found in Mammoth hot springs within Yellowstone.

Canary Spring at Mammoth Hot Springs.

Credit: Jim Peaco, Courtesy of NPS

As you get farther from the center of the hot spring, the temperatures get lower and there is a greater diversity of microbes that can survive there, Smithsonian’s Natasha Geiling reported. The spring’s outermost layer, at 131 degrees Fahrenheit (55 degrees Celsius), is a red-brown or burgundy color. Another carotenoid-carrying microbe also comes into play at this temperature: Deinococcus-Thermus Thermus creates “bright red or orange streamers,” according to a blog by the American Geophysical Union (AGU). For instance, the Lower Geyser basin in Yellowstone has a reddish hue due to this bacteria.

Researchers have gone a step further than showing that environmental features favor microbes that produce certain colors. As they reported in a 2015 paper published in the journal Applied Optics, they created a mathematical model to explain the colors within the springs. Consistent with what is seen at the Grand Prismatic Basin, the researchers, from Montana State University in the U.S. and Brandenburg University of Applied Sciences in Germany, found that in deep water, the color resulted mostly from the light’s interaction (scattering, absorption) with the water itself, whereas in the shallow areas, the color came from the reflection of light from microbial mats, whose composition depended highly on temperature.

They also reported that humans might have influenced the colors of Yellowstone’s geothermal features. In the past, the temperatures of Morning Glory Pool were significantly higher, and its color was a deep blue, they reported. As trash accumulated in the pool, somewhat clogging the vent, its temperature cooled, allowing for microbial growth and giving rise to orange-yellow microbial mats that give the pool its psychedelic appearance, according to a statement from The Optical Society.

So don’t take the chromatic beauty of Yellowstone’s hot springs for granted. They depend on microbial life, and as the Applied Optics study indicated, the bacterial composition of that microbial life could depend on us.

By Ashley P. Taylor of Live Science

Hypercarnivore Unearthed

A newfound extinct marsupial “hypercarnivore” from Australia — one that researchers say looked like a cross between a Tasmanian devil and a hyena — was about twice as big as Australia’s largest living flesh-eating marsupials, a new study finds.

Named Whollydooleya tomnpatrichorum, the predator is just one of a bevy of what scientists said were “strange, new animals”found in a fossil-rich site Down Under.

Although scientists have so far discovered only a single lower molar tooth of this predator, they deduced from the animal’s tooth that “almost certainly it was a very active predator with an extremely powerful bite,” said study lead author Mike Archer, a paleontologist at the University of New South Wales in Sydney. [Image Gallery: 25 Amazing Ancient Beasts]

Judging from the size and shape of this fossil molar, the researchers suggest W. tomnpatrichorum was what scientists call a hypercarnivore. This term “generally refers to a predator that is larger than a cat whose diet is at least 75 percent meat,” Archer told Live Science. “These are animals that specialize in killing and eating other animals, although they probably wouldn’t pass up a juicy bit of fruit from time to time.”

The scientists estimated that this hypercarnivore weighed at least 44 to 55 lbs. (20 to 25 kilograms). In comparison, Australia’s largest living carnivorous marsupial, the Tasmanian devil, weighs only about 22 lbs. (10 kg).

Back when W. tomnpatrichorum dwelledin the forests of northwest Australia during the late Miocene period, which lasted from about 12 million to 5 million years ago, Australia was beginning to dry out.

“Although Whollydooleya terrorized the drying forests around 5 million years ago, its own days were numbered,” Archer said in a statement. “While it was at least distantly related to living and recently living carnivorous marsupials such as devils, thylacines and quolls, it appears to have represented a distinctive subgroup of hypercarnivores that did not survive into the modern world. Climate change can be a merciless eliminator of the mightiest of mammals.”

An illustration showing the size comparison of Australian marsupials, including a newly described extinct species of carnivorous marsupial, <em>Whollydooleya tomnpatrichorum</em>.
An illustration showing the size comparison of Australian marsupials, including a newly described extinct species of carnivorous marsupial, Whollydooleya tomnpatrichorum.

Credit: Karen Black/UNSW

Much remains a mystery about the animals from the late Miocene of Australia; fossils of land animals from this period are extremely rare because of Australia’s increasing aridity back then, the researchers said.

“Fortunately, in 2012, we discovered a whole new fossil field that lies beyond the internationally famous Riversleigh World Heritage Area fossil deposits in northwestern Queensland,” Archer said in a statement. “This exciting new area, New Riversleigh, was detected by remote sensing using satellite data.”

This discovery “reminds us about how much of the Australian continent remains virtually unexplored,” Archer said. “Much of remote, northern Australia has yet to be explored for potentially even more exciting paleontological deposits.” [6 Extinct Animals That Could Be Brought Back to Life]

Stereophotographs of a lower molar of the new hypercarnivorous marsupial <em>Whollydooleya tomnpatrichorum</em>.
Stereophotographs of a lower molar of the new hypercarnivorous marsupial Whollydooleya tomnpatrichorum.

Credit: Suzanne Hand/UNSW

But these regions tend to be difficult to reach, Archer said. “We can’t get vehicles anywhere near this area, hence we have to use helicopters, and they’re very expensive,” he added. The scientists began to carefully explore New Riversleigh in 2013 with the help of a grant from the National Geographic Society.

The new species’ molar was one of the first fossil teeth unearthed from an especially fossil-rich site in the area, which study team member Phil Creaser discovered. This fossil-rich locale was named Whollydooley Hill in honor of Creaser’s partner, Genevieve Dooley. The species was, in turn, named after Whollydooley Hill, as well as Tom and Pat Rich, “who are well-respected research colleagues,” Archer said.

All in all, the site is yielding “the remains of a bevy of strange, new, small- to medium-sized creatures, with W. tomnpatrichorum the first one to be described,” Archer said in a statement.

One strange feature of these fossil teeth is that they were often worn down, Archer said. This suggests there was abrasive dust in the hypercarnivore’s habitat and that the plants some of these animals were eating in the late Miocene may have been tough and drought-resistant, he said.

Previous research did unearth medium to large-size late Miocene animals in Australia, but “those deposits give almost no information about the small to medium-sized mammals that existed at the same time, which generally provide more clues about the nature of prehistoric environments and climates,” study co-author Suzanne Hand, a professor in the School of Biological, Earth and Environmental Sciences at the University of New South Wales, said in a statement.

In contrast, “the small to medium-size mammals from the New Riversleigh deposits will reveal a great deal about how Australia’s inland environments and animals changed between 12 [million] and 5 million years ago, a critical time when increasing dryness ultimately led to the ice ages of the Pleistocene,” study co-author Karen Black, a vertebrate paleontologist at the University of New South Wales, said in a statement.

All in all, W. tomnpatrichorum‘s large size is an early sign of the trend toward gigantism seen in many lineages of Australian marsupials, Archer said. “These new discoveries are starting to fill in a large hole in our understanding about how Australia’s land animals transformed from being small denizens of its ancient, wet forests to huge survivors on the second most arid continent on Earth,” Archer said in a statement.

The Whollydooley site also contains signs of windblown sand grains, which are absent from the older nearby Riversleigh World Heritage deposits. These windblown sand grains suggest “that at least two aspects of a drier Australia were taking shape — less water and more wind,” Archer said. “Today, windblown sand grains are a normal part of every deposit forming in almost the whole of the continent.”

In the future, “we have to raise funds to continue the remote exploration and dissolve the bone-rich blocks that we recover during these explorations,” Archer said.

The scientists detailed their findings in the July 30 issue of the journal Memoirs of Museum Victoria.

By Charles Q. Choi from Live Science

Ancient Habitat for Life

By The Daily Galaxy

Wide view of sunset over Gusev Crater taken by NASA’s Spirit Rover in 2005. Both blue aureole and pink sky are seen. Because of the fine nature of Martian dust, it can scatter blue light coming from the Sun forward towards the observer.

The “Pot of Gold” rock outcrop inGusev Crater that Spirit Mars Rover examined in late 2005 revealed high concentrations of carbonate, which originates in wet, near-neutral conditions, but dissolves in acid. The ancient water indicated by this find was not acidic; hence, it was favorable as a habitat for life.”This is one of the most significant findings by the rovers,” said Steve Squyres of Cornell University a principal investigator for the Mars twin rovers, Spirit and Opportunity. “A substantial carbonate deposit in a Mars outcrop tells us that conditions that could have been quite favorable for life were present at one time in that place.”

Spirit inspected rock outcrops, striking a bonanza at one the NASA scientists named Comanche, along the rover’s route from the top of Husband Hill to the vicinity of the Home Plate plateau. Magnesium iron carbonate makes up about one-fourth of the measured volume in Comanche. That is a tenfold higher concentration than any previously identified for carbonate in a Martian rock.

“We used detective work combining results from three spectrometers to lock this down,” said Dick Morris, a member of a rover science team at NASA’s Johnson Space Center in Houston.”The instruments gave us multiple, interlocking ways of confirming the magnesium iron carbonate, with a good handle on how much there is.”

Massive carbonate deposits on Mars have been sought for years without much success. Numerous channels apparently carved by flows of liquid water on ancient Mars suggest the planet was formerly warmer, thanks to greenhouse warming from a thicker atmosphere than exists now.

 

Gusev_homeplate_fumerols_20081001_12_1024

 

Shown above is a National Geographic artist’s concept of how Gusev Crater might have appeared billions of years ago. The ancient, dense Martian atmosphere was probably rich in carbon dioxide, because that gas makes up nearly all the modern, very thin atmosphere. It is important to determine where most of the carbon dioxide went. Some theorize it departed to space.

Others hypothesize that it left the atmosphere by the mixing of carbon dioxide with water under conditions that led to forming carbonate minerals. That possibility, plus finding small amounts of carbonate in meteorites that originated from Mars, led to expectations in the 1990s that carbonate would be abundant on Mars. However, mineral-mapping spectrometers on orbiters since then have found evidence of localized carbonate deposits in only one area, plus small amounts distributed globally in Martian dust.

Spirit’s Alpha Particle X-ray Spectrometer instrument detected a high concentration of light elements, a group including carbon and oxygen, that helped quantify the carbonate content.

Building Blocks

By The Daily Galaxy

DNA is synonymous with life, but where did it originate? One way to answer this question is to try to recreate the conditions that formed DNA’s molecular precursors. These precursors are carbon ring structures with embedded nitrogen atoms, key components of nucleobases, which themselves are building blocks of the double helix.

Now, researchers from the U.S. Department of Energy’s Lawrence Berkeley National Lab (Berkeley Lab) and the University of Hawaii atManoa have shown for the first time that cosmic hot spots, such as those near stars, could be excellent environments for the creation of these nitrogen-containing molecular rings.In a new paper in the Astrophysical Journal, the team describes the experiment in which they recreate conditions around carbon-rich, dying stars to find formation pathways of the important molecules.

“This is the first time anyone’s looked at a hot reaction like this,” says Musahid Ahmed, scientist in the Chemical Sciences Division at Berkeley Lab. It’s not easy for carbon atoms to form rings that contain nitrogen, he says. But this new work demonstrates the possibility of a hot gas phase reaction, what Ahmed calls the “cosmic barbeque.”

For decades, astronomers have pointed their telescopes into space to look for signatures of these nitrogen-containing double carbon rings called quinoline, Ahmed explains. They’ve focused mostly on the space between stars called the interstellar medium. While the stellar environment has been deemed a likely candidate for the formation of carbon ring structures, no one had spent much time looking there for nitrogen-containing carbon rings.

To recreate the conditions near a star, Ahmed and his long-time collaborator, Ralf Kaiser, professor of chemistry at the University of Hawaii, Manoa, and their colleagues, which include Dorian Parker at Hawaii, and Oleg Kostko and Tyler Troy of Berkeley Lab, turned to the Advanced Light Source (ALS), a Department of Energy user facility located at Berkeley Lab.

At the ALS, the researchers used a device called a hot nozzle, previously used to successfully confirm soot formation during combustion. In the present study the hot nozzle is used to simulate the pressures and temperatures in stellar environments of carbon-rich stars. Into the hot nozzle, the researchers injected a gas made of a nitrogen-containing single ringed carbon molecule and two short carbon-hydrogen molecules called acetylene.

Then, using synchrotron radiation from the ALS, the team probed the hot gas to see which molecules formed. They found that the 700-Kelvin nozzle transformed the initial gas into one made of the nitrogen-containing ring molecules called quinolone and isoquinoline, considered the next step up in terms of complexity.

“There’s an energy barrier for this reaction to take place, and you can exceed that barrier near a star or in our experimental setup,” Ahmed says. “This suggests that we can start looking for these molecules around stars now.”

These experiments provide compelling evidence that the key molecules of quinolone and isoquinoline can be synthesized in these hot environments and then be ejected with the stellar wind to the interstellar medium – the space between stars, says Kaiser.

“Once ejected in space, in cold molecular clouds, these molecules can then condense on cold interstellar nanoparticles, where they can be processed and functionalized.” Kaiser adds. “These processes might lead to more complex, biorelevant molecules such as nucleobases of crucial importance to DNA and RNA formation.”

In 2008, cosmologists mapping out the origins of high-energy cosmic rays reaching Earth have discovered two unexpected “hotspots” shown in the image at the top of the page.