adplus-dvertising
Connect with us

Science

Curiosity Finds Organic Molecules That Could Have Been Produced by Life on Mars – Universe Today

Published

 on


What do coal, crude oil, and truffles have in common? Go ahead. We’ll wait.

The answer is thiophenes, a molecule that behaves a lot like benzene. Crude oil, coal, and truffles all contain thiophenes. So do a few other substances. MSL Curiosity found thiophenes on Mars, and though that doesn’t conclusively prove that Mars once hosted life, its discovery is an important milestone for the rover. Especially since truffles are alive, and oil and coal used to be, sort of.

A quote from NASA’s Curiosity website reminds us what the rover’s mission is: “Curiosity was designed to assess whether Mars ever had an environment able to support small life forms called microbes. In other words, its mission is to determine the planet’s ‘habitability.’ ”

A pair of scientists from Berlin’s Technical University thinks that the thiophenes Curiosity found on Mars could be a signature from early Martian life. If they’re right, then Mars was, at one time, inhabited by simple life forms. They’ve presented their findings in a new paper.

The pair are Dirk Schulze-Makuch and Jacob Heinz. Schulze-Makuch is also an astrobiologist at Washington State University. Their paper is titled “Thiophenes on Mars: Biotic or Abiotic Origin?” It’s published in the journal Astrobiology.

MSL Curiosity found the thiophenes in Martian sediments. It’s one of a number of interesting molecules found on Mars that might have a biotic origin. Thiophenes can also have an abiotic origin through diagenesis, which are physical and chemical changes that take place as sediments become sedimentary rock.

Sedimentary rocks on Mars, investigated by NASA’s Curiosity Mars rover. Thiophenes can be produced by biotic processes, or by abiotic processes, like when sediment becomes sedimentary rock. By NASA/JPL-Caltech/MSSS – Catalog page · Full-res (JPEG · TIFF), Public Domain, https://commons.wikimedia.org/w/index.php?curid=30263203

In order to find the thiophenes in the Martian sediments, Curiosity had to first heat the sample above 500 Celsius. Then Curiosity examined it with the SAM (Sample Analysis at Mars) instrument. SAM analyzed the gases coming off the sample using gas chromatography-mass spectrometry. SAM is actually three instruments in one, and together they search for organic chemicals.

“We identified several biological pathways for thiophenes that seem more likely than chemical ones, but we still need proof,” Dirk Schulze-Makuch said in a press release. “If you find thiophenes on Earth, then you would think they are biological, but on Mars, of course, the bar to prove that has to be quite a bit higher.”

Thiophenes have a structure that suggests a possible biotic origin. They have four carbon atoms and a single sulfur atom arranged in a ring, with hydrogen atoms. Hydrocarbons are essential elements in organic chemistry, and hydrocarbon molecules containing atoms of sulfur are an important part of the study of organic chemistry.

The thiophene molecule. Image Credit: By Jynto - Own work, Public Domain, https://commons.wikimedia.org/w/index.php?curid=11357639
The thiophene molecule. Image Credit: By Jynto – Own work, Public Domain, https://commons.wikimedia.org/w/index.php?curid=11357639

There are non-biological sources of thiophenes. They can be created by meteor impacts, and by a process called thermochemical sulfate reduction, where compounds are heated above 120 Celsius (248 F).

But it’s the biological sources of thiophenes that are the most interesting. In the distant past, perhaps about 3 billion years ago, Mars was a much different place. It likely had a warm and wet environment that could’ve harbored life. Those ancient bacteria could’ve facilitated a sulfate reduction process biologically, which resulted in the thiophenes that Curiosity detected.

Technology moves quickly. Curiosity was much more advanced than its predecessors Spirit and Opportunity. It uses technology that breaks large molecules down into smaller molecules for analysis. But when the next Mars rover, the ESA’s ExoMars mission, arrives on the red planet, it’ll bring even more advanced technology.

ExoMars’ MOMA (Mars Organic Molecule Analyzer) is the premier astrobiology instrument on the ExoMars rover, and also the largest instrument. It’s a little more refined than Curiosity’s instrument, and it doesn’t rely on fragmentation to study molecules. MOMA will allow the collection and study of larger molecules.

The ESA's ExoMars rover will land on Mars in 2021 and continue the search for evidence of ancient life on Mars.  Credit:ESA
The ESA’s ExoMars rover will land on Mars in 2021 and continue the search for evidence of ancient life on Mars. Credit:ESA

MOMA will use the concept of homochirality to identify molecules as either biotic or abiotic, something that MSL Curiosity can’t do. Homochirality is a property of amino acids and sugars. Many of the organic molecules necessary for life, including amino acids and sugars, can come in both left-handed and right-handed types, referred to as their chirality.

In Earth life, 19 of the 20 amino acids are homochiral and left-handed, while sugars, which are part of RNA and DNA, are homochiral and right-handed. Homochirality is essential for an efficient metabolism. But the same chemicals produced in a laboratory will have equal abundances of left-handed and right-handed types. The basic idea is that if we find homochiral building blocks of life, they likely have a biological source.

 Many of life's most important molecules can exist in left- or right-handed configurations. They need to able to "shake hands" with each other in order to function. People shake hands right-to-right, or maybe left-to-right. It's not possible to shake right-to-left, or vice versa. Image Credit: ESA
Life’s molecules need to able to “shake hands” with each other in order to function. People shake hands right-to-right, or maybe left-to-right. It’s not possible to shake right-to-left, or vice versa. Image Credit: ESA

Isotope ratios can also differentiate between the same atoms with either biotic or abiotic origins. Schulze-Makuch and Heinze, the authors of this paper, think that some of the data from the ExoMars rover should be used to also look for isotopes of carbon and sulfur. In particular, the lighter isotopes of both. They think that’s where we’re most likely to find a biological origin.

“Organisms are ‘lazy.’ They would rather use the light isotope variations of the element because it costs them less energy,” Schulze-Makuch said.

Lifeforms tend to alter the balance between light isotopes and heavy isotopes of the elements they produce. That ratio is different than the ratio in the same elements in their building blocks. That’s a “tell-tale sign of life” according to Schulze Makuch.

The discussion over life on Mars has been ongoing for decades. When the Viking landers were on Mars in 1976, they conducted the very first in-situ measurements, looking for organic compounds. What they found is still somewhat controversial today, because no lab experiments have been able to completely recreate those results. However, it’s widely believed in the scientific community that the Viking findings can be explained by abiotic sources.

The late, great Carl Sagan stands next to a model of the Viking lander. Credit: NASA

The ExoMars rover is our next step in understanding ancient Mars’ habitability. Its experimental results may bring us one step closer to knowing definitively if Mars once hosted life. But it might not get us all the way to that conclusion, unfortunately.

“As Carl Sagan said ‘extraordinary claims require extraordinary evidence,’” Schulze-Makuch said. “I think the proof will really require that we actually send people there, and an astronaut looks through a microscope and sees a moving microbe.”

More:

Let’s block ads! (Why?)

728x90x4

Source link

Continue Reading

News

Here’s how Helene and other storms dumped a whopping 40 trillion gallons of rain on the South

Published

 on

 

More than 40 trillion gallons of rain drenched the Southeast United States in the last week from Hurricane Helene and a run-of-the-mill rainstorm that sloshed in ahead of it — an unheard of amount of water that has stunned experts.

That’s enough to fill the Dallas Cowboys’ stadium 51,000 times, or Lake Tahoe just once. If it was concentrated just on the state of North Carolina that much water would be 3.5 feet deep (more than 1 meter). It’s enough to fill more than 60 million Olympic-size swimming pools.

“That’s an astronomical amount of precipitation,” said Ed Clark, head of the National Oceanic and Atmospheric Administration’s National Water Center in Tuscaloosa, Alabama. “I have not seen something in my 25 years of working at the weather service that is this geographically large of an extent and the sheer volume of water that fell from the sky.”

The flood damage from the rain is apocalyptic, meteorologists said. More than 100 people are dead, according to officials.

Private meteorologist Ryan Maue, a former NOAA chief scientist, calculated the amount of rain, using precipitation measurements made in 2.5-mile-by-2.5 mile grids as measured by satellites and ground observations. He came up with 40 trillion gallons through Sunday for the eastern United States, with 20 trillion gallons of that hitting just Georgia, Tennessee, the Carolinas and Florida from Hurricane Helene.

Clark did the calculations independently and said the 40 trillion gallon figure (151 trillion liters) is about right and, if anything, conservative. Maue said maybe 1 to 2 trillion more gallons of rain had fallen, much if it in Virginia, since his calculations.

Clark, who spends much of his work on issues of shrinking western water supplies, said to put the amount of rain in perspective, it’s more than twice the combined amount of water stored by two key Colorado River basin reservoirs: Lake Powell and Lake Mead.

Several meteorologists said this was a combination of two, maybe three storm systems. Before Helene struck, rain had fallen heavily for days because a low pressure system had “cut off” from the jet stream — which moves weather systems along west to east — and stalled over the Southeast. That funneled plenty of warm water from the Gulf of Mexico. And a storm that fell just short of named status parked along North Carolina’s Atlantic coast, dumping as much as 20 inches of rain, said North Carolina state climatologist Kathie Dello.

Then add Helene, one of the largest storms in the last couple decades and one that held plenty of rain because it was young and moved fast before it hit the Appalachians, said University of Albany hurricane expert Kristen Corbosiero.

“It was not just a perfect storm, but it was a combination of multiple storms that that led to the enormous amount of rain,” Maue said. “That collected at high elevation, we’re talking 3,000 to 6000 feet. And when you drop trillions of gallons on a mountain, that has to go down.”

The fact that these storms hit the mountains made everything worse, and not just because of runoff. The interaction between the mountains and the storm systems wrings more moisture out of the air, Clark, Maue and Corbosiero said.

North Carolina weather officials said their top measurement total was 31.33 inches in the tiny town of Busick. Mount Mitchell also got more than 2 feet of rainfall.

Before 2017’s Hurricane Harvey, “I said to our colleagues, you know, I never thought in my career that we would measure rainfall in feet,” Clark said. “And after Harvey, Florence, the more isolated events in eastern Kentucky, portions of South Dakota. We’re seeing events year in and year out where we are measuring rainfall in feet.”

Storms are getting wetter as the climate change s, said Corbosiero and Dello. A basic law of physics says the air holds nearly 4% more moisture for every degree Fahrenheit warmer (7% for every degree Celsius) and the world has warmed more than 2 degrees (1.2 degrees Celsius) since pre-industrial times.

Corbosiero said meteorologists are vigorously debating how much of Helene is due to worsening climate change and how much is random.

For Dello, the “fingerprints of climate change” were clear.

“We’ve seen tropical storm impacts in western North Carolina. But these storms are wetter and these storms are warmer. And there would have been a time when a tropical storm would have been heading toward North Carolina and would have caused some rain and some damage, but not apocalyptic destruction. ”

___

Follow AP’s climate coverage at https://apnews.com/hub/climate

___

Follow Seth Borenstein on Twitter at @borenbears

___

Associated Press climate and environmental coverage receives support from several private foundations. See more about AP’s climate initiative here. The AP is solely responsible for all content.

Source link

Continue Reading

Science

‘Big Sam’: Paleontologists unearth giant skull of Pachyrhinosaurus in Alberta

Published

 on

 

It’s a dinosaur that roamed Alberta’s badlands more than 70 million years ago, sporting a big, bumpy, bony head the size of a baby elephant.

On Wednesday, paleontologists near Grande Prairie pulled its 272-kilogram skull from the ground.

They call it “Big Sam.”

The adult Pachyrhinosaurus is the second plant-eating dinosaur to be unearthed from a dense bonebed belonging to a herd that died together on the edge of a valley that now sits 450 kilometres northwest of Edmonton.

It didn’t die alone.

“We have hundreds of juvenile bones in the bonebed, so we know that there are many babies and some adults among all of the big adults,” Emily Bamforth, a paleontologist with the nearby Philip J. Currie Dinosaur Museum, said in an interview on the way to the dig site.

She described the horned Pachyrhinosaurus as “the smaller, older cousin of the triceratops.”

“This species of dinosaur is endemic to the Grand Prairie area, so it’s found here and nowhere else in the world. They are … kind of about the size of an Indian elephant and a rhino,” she added.

The head alone, she said, is about the size of a baby elephant.

The discovery was a long time coming.

The bonebed was first discovered by a high school teacher out for a walk about 50 years ago. It took the teacher a decade to get anyone from southern Alberta to come to take a look.

“At the time, sort of in the ’70s and ’80s, paleontology in northern Alberta was virtually unknown,” said Bamforth.

When paleontogists eventually got to the site, Bamforth said, they learned “it’s actually one of the densest dinosaur bonebeds in North America.”

“It contains about 100 to 300 bones per square metre,” she said.

Paleontologists have been at the site sporadically ever since, combing through bones belonging to turtles, dinosaurs and lizards. Sixteen years ago, they discovered a large skull of an approximately 30-year-old Pachyrhinosaurus, which is now at the museum.

About a year ago, they found the second adult: Big Sam.

Bamforth said both dinosaurs are believed to have been the elders in the herd.

“Their distinguishing feature is that, instead of having a horn on their nose like a triceratops, they had this big, bony bump called a boss. And they have big, bony bumps over their eyes as well,” she said.

“It makes them look a little strange. It’s the one dinosaur that if you find it, it’s the only possible thing it can be.”

The genders of the two adults are unknown.

Bamforth said the extraction was difficult because Big Sam was intertwined in a cluster of about 300 other bones.

The skull was found upside down, “as if the animal was lying on its back,” but was well preserved, she said.

She said the excavation process involved putting plaster on the skull and wooden planks around if for stability. From there, it was lifted out — very carefully — with a crane, and was to be shipped on a trolley to the museum for study.

“I have extracted skulls in the past. This is probably the biggest one I’ve ever done though,” said Bamforth.

“It’s pretty exciting.”

This report by The Canadian Press was first published Sept. 25, 2024.

The Canadian Press. All rights reserved.

Source link

Continue Reading

News

The ancient jar smashed by a 4-year-old is back on display at an Israeli museum after repair

Published

 on

 

TEL AVIV, Israel (AP) — A rare Bronze-Era jar accidentally smashed by a 4-year-old visiting a museum was back on display Wednesday after restoration experts were able to carefully piece the artifact back together.

Last month, a family from northern Israel was visiting the museum when their youngest son tipped over the jar, which smashed into pieces.

Alex Geller, the boy’s father, said his son — the youngest of three — is exceptionally curious, and that the moment he heard the crash, “please let that not be my child” was the first thought that raced through his head.

The jar has been on display at the Hecht Museum in Haifa for 35 years. It was one of the only containers of its size and from that period still complete when it was discovered.

The Bronze Age jar is one of many artifacts exhibited out in the open, part of the Hecht Museum’s vision of letting visitors explore history without glass barriers, said Inbal Rivlin, the director of the museum, which is associated with Haifa University in northern Israel.

It was likely used to hold wine or oil, and dates back to between 2200 and 1500 B.C.

Rivlin and the museum decided to turn the moment, which captured international attention, into a teaching moment, inviting the Geller family back for a special visit and hands-on activity to illustrate the restoration process.

Rivlin added that the incident provided a welcome distraction from the ongoing war in Gaza. “Well, he’s just a kid. So I think that somehow it touches the heart of the people in Israel and around the world,“ said Rivlin.

Roee Shafir, a restoration expert at the museum, said the repairs would be fairly simple, as the pieces were from a single, complete jar. Archaeologists often face the more daunting task of sifting through piles of shards from multiple objects and trying to piece them together.

Experts used 3D technology, hi-resolution videos, and special glue to painstakingly reconstruct the large jar.

Less than two weeks after it broke, the jar went back on display at the museum. The gluing process left small hairline cracks, and a few pieces are missing, but the jar’s impressive size remains.

The only noticeable difference in the exhibit was a new sign reading “please don’t touch.”

The Canadian Press. All rights reserved.

Source link

Continue Reading

Trending