Tag: life
Giant Volcano With Glacier On Mars May Have Been A Nice Place For Life

Giant Volcano With Glacier On Mars May Have Been A Nice Place For Life

By Amina Khan, Los Angeles Times

If life existed on Mars in the recent past, the best spot for it could have been on a giant volcano once encrusted with a glacier, according to a team of Brown University scientists using data from NASA’s Mars Reconnaissance Orbiter.

Microbial life could potentially have thrived for a time at the foot of Arsia Mons, a giant volcano about twice as tall as Mount Everest, while the dinosaurs were just coming into their own on Earth, according to the study published in the journal Icarus.

Though an active volcano may not sound particularly inviting, this combination of ice and heat would have contained massive, sheltered pockets of water — from melted ice — that could have lasted for hundreds or even a few thousand years.

“I was very excited,” lead author Kathleen Scanlon, a doctoral student and geologist at Brown University, said of the telltale signs left on the Martian surface that led to the team’s conclusions. “It’s all a really nice suite of land forms that together all point to the exact same process. So that was really cool.”

The findings come as NASA and other space agencies send more spacecraft and robots to the Red Planet to better understand how life-friendly Mars was in the past — and whether certain spots were better suited for living things than others.

Recent research has shown that the northwest side of Arsia Mons may have been covered in glacier ice, judging by marks in the terrain that resemble those left by glaciers in Antarctica’s McMurdo Dry Valleys. Around that time, about 210 million years ago, the volcano was active, spewing out lava from beneath the ground and melting some of the thick layer of glacial ice above.

Scanlon looked for certain shapes in the lava that would reveal the conditions under which the lava was coming out. She found a number of striking forms, including pillow-like lava, which extrude into giant rounded globules. On Earth, these pillows form under immense pressure at the bottom of the ocean. On Mars, it could mean the lava was under extreme pressure because it was squeezing out from underneath a glacier.

Two of the liquid bubbles caused by subsequent melting in the solid glacial ice would have held about 40 cubic kilometers of water each, making each of them roughly a third the size of Lake Tahoe. The water in these deposits could have remained liquid for centuries or more, the researchers said.

Microbes trapped in a subglacial lake, in freezing temperatures, total darkness and high pressures may sound extreme, but organisms do it on Earth too. A recent study of ice cores from a subglacial lake in Antarctica found DNA from a variety of microbes living more than 2 miles beneath the ice.

Of course, even a potentially life-friendly zone like Arsia Mons would not have lasted long on geological timescales. At its best, it could have potentially hosted microbes that had already emerged billions of years before, when Mars might have been warmer and wetter.

So the most important thing to understand is whether Mars was habitable more than 3.5 billion years ago, very early in its history, Scanlon noted. If not, then Arsia Mons’ habitability is probably moot. NASA’s Curiosity rover recently dug up some rock in Gale Crater and found some very watery environments rich in chemical building blocks for life. Just before the launch of the atmosphere-testing MAVEN mission last year, NASA released a stunning video of a past Mars, filled with puffy clouds and blue lakes.

But whether much of Mars was so life-friendly, and how long this wet era may have lasted, is up for debate. The less common these life-friendly spots were, and the shorter-lived they were, the less likely that life was able to emerge on the Red Planet. For now, the jury’s out on that mystery.

“If we can confirm that there was life around then, then our next question is, how long was it able to survive, and could there still be dormant microbes lying somewhere around on the surface?” Scanlon said. “I think Arsia Mons would be a good site to answer questions like that — if that does become a question.”

Photo: Luke Bryant via Flickr

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Small Microbes Almost Killed All Life On Earth, Study Suggests

Small Microbes Almost Killed All Life On Earth, Study Suggests

By Deborah Netburn, Los Angeles Times

LOS ANGELES — Tiny microbes on the bottom of the ocean floor may have been responsible for the largest extinction event our planet has ever seen, according to a new study.

These microbes of death were so small, that one billion of them could fit in a thimble-full of ocean sediment, and yet, they were almost responsible for killing off all the life on our planet, the scientists suggest.

The end-Permian extinction was the most catastrophic mass extinction the Earth has ever seen. It started roughly 252 million years ago — long before the dinosaurs — and it continued for 20,000 years. By the time it was over, nearly 90 percent of all life on Earth had been destroyed, the scientists say.

“It was not as dramatic as the impact that probably killed the dinosaurs, but it was worse,” said Gregory Fournier, an evolutionary biologist at MIT. “Things were very close to being over for good.”

Scientists have struggled to understand exactly what caused the long, slow, mass die-off in this dark era of our planet’s history. The geologic record tells us there was a sharp uptick of C02 levels at the time. That would have caused the oceans to acidify and the Earth to heat up, making the environment inhospitable for most forms of life. But what actually caused the C02 levels to rise has remained a mystery.

Some scientists have suggested an asteroid impact could be to blame; others have proposed that volcanic activity or coal fires might be the culprit.

Now, in a paper published this week in PNAS, researchers from the Massachusetts Institute of Technology and the Chinese Academy of Sciences in Nanjing, China, have fingered a new and unlikely suspect — a tiny methane-spewing microbe known as Methanosarcina.

The first clue that microscopic microbes could be involved in the greatest die-off the Earth has ever known came when MIT geophysicist Dan Rothman was looking at how carbon levels grew during this time. What he saw was not a straight line, but rather a rapid upward curve.

“The growth was like what you might see in a real estate bubble, or a financial bubble,” he explained. “If the C02 came from the sudden combustion of a coal field in Siberia it wouldn’t behave this way. It has this special character that is consistent with microbial processes.”

It was the first time anyone had suggested microbes might be involved with the end-Permian extinction, but far from the first time that microbes have been accused of changing the chemistry of our planet. For example, photosynthetic microbes are responsible for creating the first oxygen in the Earth’s atmosphere.

“It is absolutely normal that microbes are mediating the great elemental cycles,” said Rothman. “What they do is crucial. And if they do better or worse, things change.”

Fournier put it this way: “Microbiologists like to say, ‘Microbes rule the Earth, and we just live on it.’”

To figure out which specific microbe might have a hand in this ancient catastrophe, Rothman took his research to Fournier, who had published a paper about Methanosarcina in 2008. The paper showed that sometime in the last 400 million years, Methanosarcina was the recipient of a gene transfer that allowed it to produce methane more efficiently than ever before.

After seeing Rothman’s analysis, Fournier worked to date the time of the gene transfer more specifically and found it most likely occurred about 250 million years ago.

Although the researchers cannot say for certain that the microbe and the vast quantities of methane it produced were responsible for the end-Permian extinction, they do have one more line of evidence to support their hypothesis. In order to turn acetate into methane, Methanosarcina needs nickel.

“Even if they had all the food in the world they would be limited if they were starved for nickel,” Fournier said.

But if there was a lot of nickel around, the microbes would be unhindered. And, wouldn’t you know, much of the volcanic activity at the time occurred around the Siberian traps, which has some of the world’s largest deposits of nickel. Further more, the researchers found an increase in nickel in sediments from that time.

“Our proposal is unusual, but it does bring together many observations, and ties a lot of stuff together,” Rothman said. “That doesn’t make it right, but it is consistent, and that’s what is necessary to move forward and provide further tests.”

 

Let Us Pause To Remember

It’s mid-August, and millions of young adults are girding for the next big adventure of their lives.

Many are packing for college. Others are moving into their first home away from home, starting new jobs maybe, or setting up house with new spouses.

Life is unfolding under a canopy of new beginnings. “Onward!” cry the parents. Even if we don’t yet feel it in our hearts.

It’s been a few years since I was the parent who climbed into a suddenly empty car and drove away without the kid who consumed 18-plus years of my life. But this time of year always reminds me of just such a trip in another August, in 2005. I still wince in recalling how, in a single week, I went from a self-pitying empty nester to an unspeakably grateful mother after 20 young Marines were killed in Iraq.

Last Thursday, the Department of Defense released the names of the 30 Americans — all but one of them well under 40 — who died Aug. 6 in Wardak province, Afghanistan, after their CH-47 Chinook helicopter crashed.

Please take a few minutes to read aloud this list of names, ages and hometowns. If you say their names out loud, the losses — and the lack of shared sacrifice — become far more real. That’s a warning and a promise.

Let us pause to remember:

Lt. Cmdr. (SEAL) Jonas B. Kelsall, 32, of Shreveport, La.

Special Warfare Operator Master Chief Petty Officer (SEAL) Louis J. Langlais, 44, of Santa Barbara, Calif.

Special Warfare Operator Senior Chief Petty Officer (SEAL) Thomas A. Ratzlaff, 34, of Green Forest, Ark.

Explosive Ordnance Disposal Technician Senior Chief Petty Officer (Expeditionary Warfare Specialist/Freefall Parachutist) Kraig M. Vickers, 36, of Kokomo, Hawaii.

Special Warfare Operator Chief Petty Officer (SEAL) Brian R. Bill, 31, of Stamford, Conn.

Special Warfare Operator Chief Petty Officer (SEAL) John W. Faas, 31, of Minneapolis.

Special Warfare Operator Chief Petty Officer (SEAL) Kevin A. Houston, 35, of West Hyannisport, Mass.

Special Warfare Operator Chief Petty Officer (SEAL) Matthew D. Mason, 37, of Kansas City, Mo.

Special Warfare Operator Chief Petty Officer (SEAL) Stephen M. Mills, 35, of Fort Worth, Texas.

Explosive Ordnance Disposal Technician Chief Petty Officer (Expeditionary Warfare Specialist/Freefall Parachutist/Diver) Nicholas H. Null, 30, of Washington, W.Va.

Special Warfare Operator Chief Petty Officer (SEAL) Robert J. Reeves, 32, of Shreveport, La.

Special Warfare Operator Chief Petty Officer (SEAL) Heath M. Robinson, 34, of Detroit.

Special Warfare Operator Petty Officer 1st Class (SEAL) Darrik C. Benson, 28, of Angwin, Calif.

Special Warfare Operator Petty Officer 1st Class (SEAL/Parachutist) Christopher G. Campbell, 36, of Jacksonville, N.C.

Information Systems Technician Petty Officer 1st Class (Expeditionary Warfare Specialist/Freefall Parachutist) Jared W. Day, 28, of Taylorsville, Utah.

Master-at-Arms Petty Officer 1st Class (Expeditionary Warfare Specialist) John Douangdara, 26, of South Sioux City, Neb.

Cryptologist Technician (Collection) Petty Officer 1st Class (Expeditionary Warfare Specialist) Michael J. Strange, 25, of Philadelphia.

Special Warfare Operator Petty Officer 1st Class (SEAL/Enlisted Surface Warfare Specialist) Jon T. Tumilson, 35, of Rockford, Iowa.

Special Warfare Operator Petty Officer 1st Class (SEAL) Aaron C. Vaughn, 30, of Stuart, Fla.

Special Warfare Operator Petty Officer 1st Class (SEAL) Jason R. Workman, 32, of Blanding, Utah.

Special Warfare Operator Petty Officer 1st Class (SEAL) Jesse D. Pittman, 27, of Ukiah, Calif.

Special Warfare Operator Petty Officer 2nd Class (SEAL) Nicholas P. Spehar, 24, of St. Paul, Minn.

Chief Warrant Officer David R. Carter, 47, of Centennial, Colo. He was assigned to the 2nd Battalion, 135th Aviation Regiment (General Support Aviation Battalion), Aurora, Colo.

Chief Warrant Officer Bryan J. Nichols, 31, of Hays, Kan. He was assigned to the 7th Battalion, 158th Aviation Regiment (General Support Aviation Battalion), New Century, Kan.

Sgt. Patrick D. Hamburger, 30, of Lincoln, Neb. He was assigned to the 2nd Battalion, 135th Aviation Regiment (General Support Aviation Battalion), Grand Island, Neb.

Sgt. Alexander J. Bennett, 24, of Tacoma, Wash. He was assigned to the 7th Battalion, 158th Aviation Regiment (General Support Aviation Battalion), New Century, Kan.

Spc. Spencer C. Duncan, 21, of Olathe, Kan. He was assigned to the 7th Battalion, 158th Aviation Regiment (General Support Aviation Battalion), New Century, Kan.

Tech Sgt. John W. Brown, 33, of Tallahassee, Fla.

Staff Sgt. Andrew W. Harvell, 26, of Long Beach, Calif.

Tech Sgt. Daniel L. Zerbe, 28, of York, Pa.

In a separate incident on that same day, a Marine from Canton, Ohio, was killed in combat in Helmand province, Afghanistan.

His name was Sgt. Daniel J. Patron.

He was 26 years old.

Connie Schultz is a Pulitzer Prize-winning columnist for The Plain Dealer in Cleveland and an essayist for Parade magazine. To find out more about Connie Schultz (cschultz@plaind.com) and read her past columns, please visit the Creators Syndicate Web page at www.creators.com.

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