Connect with us

Uncategorized

A Martian mash up: Meteorites tell story of Mars’ water history

Catherina Ploumidakis

Published

on

A Martian mash up- Meteorites tell story of Mars' water history

In Jessica Barnes’ palm is an ancient, coin-sized mosaic of glass, minerals and rocks as thick as a strand of wool fiber. It is a slice of Martian meteorite, known as Northwest Africa 7034 or Black Beauty, that was formed when a huge impact cemented together various pieces of Martian crust.

Barnes is an assistant professor of planetary sciences in the University of Arizona Lunar and Planetary Laboratory. She and her team chemically analyzed the Black Beauty meteorite and the infamous Allan Hills 84001 meteorite—controversial in the 1990s for allegedly containing Martian microbes—to reconstruct Mars’ water history and planetary origins.

Their analysis, published today in Nature Geoscience, showed that Mars likely received water from at least two vastly different sources early in its history. The variability the researchers found implies that Mars, unlike Earth and the moon, never had an ocean of magma completely encompassing the planet.

“These two different sources of water in Mars’ interior might be telling us something about the kinds of objects that were available to coalesce into the inner, rocky planets,” Barnes said. Two distinct planetesimals with vastly different water contents could have collided and never fully mixed. “This context is also important for understanding the past habitability and astrobiology of Mars.”

Reading the Water

“A lot of people have been trying to figure out Mars’ water history,” Barnes said. “Like, where did water come from? How long was it in the crust (surface) of Mars? Where did Mars’ interior water come from? What can water tell us about how Mars formed and evolved?”

Barnes and her team were able to piece together Mars’ water history by looking for clues in two types, or isotopes, of hydrogen. One hydrogen isotope contains one proton in its nucleus; this is sometimes called “light hydrogen.” The other isotope is called deuterium, which contains a proton and a neutron in the nucleus; this is sometimes referred to as “heavy hydrogen.” The ratio of these two hydrogen isotopes signals to a planetary scientist the processes and possible origins of water in the rocks, minerals and glasses in which they’re found.

Meteorite Mystery

For about 20 years, researchers have been recording the isotopic ratios from Martian meteorites, and their data were all over the place. There seemed to be little trend, Barnes said.

Water locked in Earth rocks is what’s called unfractionated, meaning it doesn’t deviate much from the standard reference value of ocean water—a 1:6,420 ratio of heavy to light hydrogen. Mars’ atmosphere, on the other hand, is heavily fractionated—it is mostly populated by deuterium, or heavy hydrogen, likely because the solar wind stripped away the light hydrogen. Measurements from Martian meteorites—many of which were excavated from deep within Mars by impact events—ran the gamut between Earth and Mars’ atmosphere measurements.

Barnes’ team set out to investigate the hydrogen isotope composition of the Martian crust specifically by studying samples they knew were originated from the crust: the Black Beauty and Allan Hills meteorites. Black Beauty was especially helpful because it’s a mashup of surface material from many different points in Mars’ history.

“This allowed us to form an idea of what Mars’ crust looked like over several billions of years,” Barnes said.

The isotopic ratios of the meteorite samples fell about midway between the value for Earth rocks and Mars’ atmosphere. When the researchers’ findings were compared with previous studies, including results from the Curiosity Rover, it seems that this was the case for most of Mars’ 4 billion-plus-year history.

“We thought, ok this is interesting, but also kind of weird,” Barnes said. “How do we explain this dichotomy where the Martian atmosphere is being fractionated, but the crust is basically staying the same over geological time?”

Barnes and her colleagues also grappled with trying to explain why the crust seemed so different from the Martian mantle, the rock later which lies below.

“If you try and explain this fairly constant isotopic ratio of Mars’ crust, you really can’t use the atmosphere to do that,” Barnes said. “But we know how crusts are formed. They’re formed from molten material from the interior that solidifies on the surface.”

“The prevailing hypothesis before we started this work was that the interior of Mars was more Earthlike and unfractionated, and so the variability in hydrogen isotope ratios within Martian samples was due to either terrestrial contamination or atmospheric implantation as it made its way off Mars,” Barnes said.

The idea that Mars’ interior was Earthlike in composition came from one study of a Martian meteorite thought to have originated from the mantle—the interior between the planet’s core and its surface crust.

However, Barnes said, “Martian meteorites basically plot all over the place, and so trying to figure out what these samples are actually telling us about water in the mantle of Mars has historically been a challenge. The fact that our data for the crust was so different prompted us to go back through the scientific literature and scrutinize the data.”

The researchers found that two geochemically different types of Martian volcanic rocks -enriched shergottites and depleted shergottites—contain water with different hydrogen isotope ratios. Enriched shergottites contain more deuterium than the depleted shergottites, which are more Earth-like, they found.

“It turns out that if you mix different proportions of hydrogen from these two kinds of shergottites, you can get the crustal value,” Barnes said.

She and her colleagues think that the shergottites are recording the signatures of two different hydrogen—and by extension, water—reservoirs within Mars. The stark difference hints to them that more than one source might have contributed water to Mars and that Mars did not have a global magma ocean.

Catherina previously worked as a journalist for several local newspapers until she realized the potential of internet for news reporting. She joined the team as a contributor which provided her a platform to dedicate her experience and knowledge for a wider range of audience. She excels in curating business news for the website.

Click to comment

Leave a Reply

Your email address will not be published. Required fields are marked *

Uncategorized

Another magnitude 4.2 aftershock rattles Utah

Catherina Ploumidakis

Published

on

Another magnitude 4.2 aftershock rattles Utah

SALT LAKE CITY — A magnitude 4.2 earthquake rattled Salt Lake City Thursday morning.

The aftershock hit at 7:41 a.m. and was felt in many areas of northern Utah and the surrounding area.

University of Utah seismologist, Jamie Farrell, joined Dan Evans and Kerri Cronk on Good Day Utah Thursday morning.

He was asked if a pair of sizable aftershocks nearly a month after the original 5.7 quake has any significance.

“Well keep in mind we had a couple of 4.6 aftershocks early in the sequence, so this seems a bit unusual just because it’s been a while since we felt a relatively large earthquake in this sequence,” Farrell sad. “But a 4.2 at this point isn’t necessarily out of the realm of possibilities, it’s not totally unusual although the one the other night, given the way that the sequence was going and dying off, is a little bit unexpected, but not totally unusual.”

Farrell did say Tuesday night’s 4.2 might have caused a bit of chain reaction.

“The 4.2 we had the other night might have chained a little bit, you know, triggered this event, but they’re all still considered aftershocks from the 5.7.”

Even if that is the case, Farrell said none of this is anything out of the ordinary.

“The 4.2 from the other night could have definitely caused an increase in the number of events,” he said. “But having events out this far is not unusual at all. Some aftershock sequences last weeks, some last months, there are some that last years.”

Today’s aftershock is one of over a thousand aftershocks from the March 18 5.7 magnitude quake that pounded Utah.

No word yet of any injuries or any damage, but this size quake is not expected to cause any.

Hunter Junior High School teacher, Jennifer Johnson, was recording her daily video message for students, when things started rumbling.

It wasn’t part of her lesson plan.

Johnson was pretty shocked when she felt the 4.2 magnitude aftershock.

“That was earthquakeI” she said.

Johnson posts these videos on youtube every day so students can see what she’s been up to.

Ironically, the aftershock happened on the day of The Great Utah Shakeout, where people are encouraged to hold earthquake drills.

The math and English teacher got the real thing, in real time.

“I’m done with that. I’m really tired of all of them,” she said. “I’ve gotten more used to it, got used to the twos and the ones but having those fours have been super challenging.”

Johnson said a lot of her students are really struggling with these aftershocks, so she did put a warning up on her video.

She’s heard back from some of her students who got a kick out of it

Johnson joked that she didn’t drop, cover and hold on -because it all happened so quickly.

Continue Reading

Uncategorized

Chattanooga boy and his father fighting for their lives after tornado rips through home

Catherina Ploumidakis

Published

on

Chattanooga boy and his father fighting for their lives after tornado rips through home

A Chattanooga family is asking for prayers tonight after a young boy and his father were critically injured in the Easter weekend tornado.

The family tells us the tornado ripped through their East Brainerd home, causing debris to fly through their bedrooms and knocking out 4-year-old Grayson and his father Mikey. Both are now fighting for their lives in the hospital.

It had been pouring down rain all day. Joe Meadows says tornado sirens didn’t go off until after it hit.

“Before I knew it, my brother Mikey told me to get downstairs and before I could even leave my room something came through the window, knocked me on the ground and I crawled out of the room.”

He went to find shelter and his family members.

“My brother and my nephew were knocked out unconscious bleeding from their heads in their room,” said Joe.

The bedroom that used to share a wall with Joe’s room is where they found Grayson and Mikey.

Joe picked up Grayson and took him downstairs.

“He wasn’t responsive. It was kinda like he had trouble breathing at times and there was just blood everywhere and debris from shingles and the roof in his hair,” said Joe.

Neighbors and an officer came to help carry Grayson nearly a mile down the road to safety.

“We alternated carrying him down the road and got him to the car and he rushed us to the hospital,” said Joe.

Family members are calling this a night of miracles. Both suffered major head injuries – they say Grayson is lucky to be alive.

“He’s got a little bit of movement right now,” Joe says.

And so is Mikey.

“They had to remove a large portion of the left side of his brain as well and then the titanium mesh to kind of keep it in place as well,” said Joe.

Because of COVID19 guidelines, these family and friends can only pray from afar.

“Like it’s even worse because then now the people that are hurt in the hospital like Mikey and Grayson don’t have their loved ones and friend there fighting with them there,” said family friend Cara Stanco, “They’re alone.”

But still, Cara Stanco says they will pray and fight for Grayson and Mikey.

Continue Reading

Uncategorized

Easter storms sweep South, killing at least 19 people

Catherina Ploumidakis

Published

on

Easter storms sweep South, killing at least 19 people

JACKSON, Miss. — Severe weather has swept across the South, killing at least 19 people and damaging hundreds of homes from Louisiana into the Appalachian Mountains. Many people spent part of the night early Monday sheltering in basements, closets and bathroom tubs as sirens wailed to warn of possible tornadoes.

Eleven people were killed in Mississippi, and six more died in northwest Georgia. Two other bodies were pulled from damaged homes in Arkansas and South Carolina.

The storms blew onward through the night, causing flooding and mudslides in mountainous areas, and knocking out electricity for nearly 1.3 million customers in a path from Texas to Maine, according to poweroutages.us.

Striking first on Easter Sunday across a landscape largely emptied by coronavirus stay-at-home orders, the storm front forced some uncomfortable decisions. In Alabama, Gov. Kay Ivey suspended social distancing rules, and some people wearing protective masks huddled closely together in storm shelters.

Andrew Phillips crowded into a closet-sized “safe room” with his wife and two sons after watching an online Easter service because the pandemic forced their church to halt regular worship. Then, a twister struck, shredding their house, meat-processing business and vehicles in rural Moss, Mississippi. The room, built of sturdy cinder blocks, was the only thing on their property left standing.

“I’m just going to let the insurance handle it and trust in the good Lord,” said Phillips.

The National Weather Service tallied hundreds of reports of trees down across the region, including many that punctured roofs and downed power lines. Meteorologists warned the mid-Atlantic states to prepare for potential tornadoes, wind and hail on Monday. The storms knocked down trees across Pennsylvania, and an apparently strong tornado moved through southern South Carolina, leaving chaos in its wake.

“Everything is up in the air. Power lines are down, trees are all over the place. It’s hard to get from one place to the other because the roads are blocked,” Hampton County Sheriff T.C. Smalls said.

A suspected twister lifted a house, mostly intact, and deposited it in the middle of a road in central Georgia. In Louisiana, winds ripped apart a metal airplane hangar.

Deaths were tallied in small numbers here and there, considering the storm front’s vast reach and intensity.

Mississippi’s death toll rose to 11 early Monday, the state’s emergency management agency tweeted, promising details later in the morning.

In northwest Georgia, a narrow path of destruction five miles long hit two mobile home parks, killing five people and injuring five more, Murray County Fire Chief Dewayne Bain told WAGA-TV. Another person was killed when a tree fell on a home in Cartersville, the station reported.

In Arkansas, one person was killed when a tree fell on a home in White Hall, southeast of Little Rock, the Jefferson County Department of Emergency Management said. And in South Carolina, a person was found dead in a collapsed building near Seneca as an apparent tornado struck, Oconee County Emergency Management Director Scott Krein said.

Apparent tornadoes damaged dozens of homes in a line from Seneca to Clemson. Emergency officials also were working to open shelters in the North Carolina mountains after heavy rainfall there.

In Chattanooga, Tennessee, at least 150 homes and commercial buildings were damaged and more than a dozen people treated, but none of their injuries appeared to be life-threatening, Chattanooga Fire Chief Phil Hyman said.

“It’s widespread damage that happened extremely fast, ” Hyman said. “I advise people to stay in their homes at this point. As far as safety is concerned, we still have active power lines that are down.”

The deaths in Mississippi included a married couple — Lawrence County sheriff’s deputy, Robert Ainsworth, and a Walthall County Justice Court deputy clerk, Paula Reid Ainsworth, authorities said.

“This is not how anyone wants to celebrate Easter,” said Mississippi Gov. Tate Reeves, who declared a state of emergency Sunday night. “As we reflect on the death and resurrection on this Easter Sunday, we have faith that we will all rise together.”

There were no immediate reports of serious injuries in Louisiana, even though the storm damaged between 200 and 300 homes in and around the city of Monroe, Mayor Jamie Mayo, told KNOE-TV. Flights were canceled at Monroe Regional Airport, where airport director Ron Phillips told the News-Star the storm caused up to $30 million in damage to planes inside a hangar.

Continue Reading

Trending