Flood Basalt Eruptions: NASA Warns That Some Volcanoes Could Warm Climate, Destroy Ozone Layer

By BILL STEIGERWALD, NASA GODDARD SPACE FLIGHT CENTER MAY 3, 2022

A new NASA climate simulation suggests that extremely large volcanic eruptions called “flood basalt eruptions” could significantly warm Earth’s climate and devastate the ozone layer that shields life from the Sun’s ultraviolet radiation.

The findings contradict prior research that found these volcanoes cool the climate. The simulation also suggests that while extensive flood-basalt eruptions on Mars and Venus may have helped warm their climates, they may have also doomed the long-term habitability of these worlds by contributing to water loss.

A new NASA climate simulation finds that extremely large volcanic eruptions called “flood basalt eruptions” might significantly warm Earth’s climate and devastate the ozone layer that shields life from the Sun’s UV radiation. Credit: NASA/GSFC/James Tralie

Unlike brief, explosive volcanic eruptions such as Pinatubo or January’s Hunga Tonga-Hunga Ha‘apai that occur over hours or days, flood basalts are regions with a series of eruptive episodes lasting perhaps centuries each, and occurring over periods of hundreds of thousands of years, sometimes even longer. Some happened at about the same time as mass-extinction events, and many are associated with extremely warm periods in Earth’s history. They also appear to have been common on other terrestrial worlds in our solar system, such as Mars and Venus.

“We expected intense cooling in our simulations,” said Scott Guzewich of NASA’s Goddard Space Flight Center in Greenbelt, Maryland. “However, we found that a brief cooling period was overwhelmed by a warming effect.” Guzewich is lead author of a paper about this research that was published on February 1, 2022, in the journal Geophysical Research Letters.

Image of a flood-basalt deposit on Mars in the Marte Vallis region taken by the High Resolution Science Imaging Experiment (HiRISE) instrument on board NASA’s Mars Reconnaissance Orbiter spacecraft. Credit: NASA/University of Arizona/HiRISE

While the ozone loss was not a surprise, the simulations indicated the potential magnitude of the destruction, “about two-thirds reduction over global average values, roughly equivalent to the whole planet having an ozone thinning comparable to a severe Antarctic ozone hole,” said Guzewich.

The researchers used the Goddard Earth Observing System Chemistry-Climate Model to simulate a four-year-long phase of the Columbia River Basalt (CRB) eruption that occurred between 15 million and 17 million years ago in the Pacific Northwest of the United States. The model calculated the effects of the eruption on the troposphere, the turbulent lowest layer of the atmosphere with most of the water vapor and weather, and the stratosphere, the next layer of the atmosphere that is mostly dry and calm. CRB eruptions were likely a mix of explosive events that sent material high into the upper troposphere and lower stratosphere (about 8 to 10.5 miles or 13 to 17 kilometers altitude) and effusive eruptions that did not extend above 1.9 miles (about 3 kilometers) altitude. The simulation assumed that explosive events happened four times per year and released about 80% of the eruption’s sulfur dioxide gas. They found that globally, there was a net cooling for about two years before the warming overwhelms the cooling effect. “The warming persists for about 15 years (the last two years of the eruption and then another 13 years or so),” said Guzewich.

“We expected intense cooling in our simulations. However, we found that a brief cooling period was overwhelmed by a warming effect.” — Scott Guzewich

The new simulation is the most comprehensive yet done for flood basalt eruptions and integrates the effects of atmospheric chemistry and climate dynamics on each other, revealing an important feedback mechanism that earlier simulations mi

“Eruptions like the one we simulated would emit massive amounts of sulfur dioxide gas,” said Guzewich. “Chemistry in the atmosphere quickly converts these gas molecules to solid sulfate aerosols. These aerosols reflect visible sunlight, which causes the initial cooling effect, but also absorb infrared radiation, which warms the atmosphere aloft in the upper troposphere and lower stratosphere. Warming this region of the atmosphere allows water vapor (that’s normally confined near the surface) to get mixed into the stratosphere (which is normally very dry). We see a 10,000% increase in stratospheric water vapor. Water vapor is a very effective greenhouse gas, and it emits infrared radiation that warms the planet’s surface.”

The predicted surge of water vapor into the stratosphere also helps explain the severity of the ozone layer depletion. “Ozone layer depletion happens in a couple different ways,” said Guzewich. “Following the eruption, the circulation of the stratosphere changes in ways that discourage ozone formation. Second, all that water in the stratosphere also helps destroy ozone with the hydroxyl (OH) radical.”

Flood basalts also release carbon dioxide, a greenhouse gas as well, but they don’t appear to emit enough to cause the extreme warming associated with some eruptions. The excess heating from stratospheric water vapor could provide an explanation.

Although Mars and Venus may have had oceans of water in the distant past, both are currently very dry. Scientists are investigating how these worlds lost most of their water to became inhospitable for life. If the surge of water vapor into the upper atmosphere predicted by the simulation is realistic, extensive flood volcanism could have contributed to their arid fates. When water vapor is lofted high in the atmosphere, it becomes susceptible to being broken apart by sunlight, and the lightweight hydrogen atoms from the water molecules can escape to space (water is two hydrogen atoms bound to an oxygen atom). If sustained over long periods, this could deplete oceans

Reference: “Volcanic Climate Warming Through Radiative and Dynamical Feedbacks of SO₂ Emissions” by Scott D. Guzewich, Luke D. Oman, Jacob A. Richardson, Patrick L. Whelley, Sandra T. Bastelberger, Kelsey E. Young, Jacob E. Bleacher, Thomas J. Fauchez and Ravi K. Kopparapu, 1 February 2022, Geophysical Research Letters.
DOI: 10.1029/2021GL096612

The research was funded by the NASA Goddard Sellers Exoplanet Environments Collaboration and NASA’s Center for Research and Exploration in Space Science and Technology, NASA Cooperative Agreement Award #80GSFC17M0002.

Large Bodies Helped Ancient Sea Monsters With Extremely Long Necks Swim

By UNIVERSITY OF BRISTOL MAY 3, 2022

Illustration of an Elasmosaurus, an extinct marine reptile in the genus of Plesiosaur.

A new research study finds that large bodies helped extinct marine reptiles with long necks swim.

According to new research findings from scientists at the University of Bristol, body size is more important than body shape in determining the energy economy of swimming for aquatic animals.

This study, published in the journal Communications Biology on April 28, 2022, shows that large bodies help overcome the extra drag produced by extreme morphology, debunking a long-standing belief that there is an optimal body shape for low drag.

One significant finding of this research is that the huge necks of extinct elasmosaurs did add extra drag, but this was compensated by the evolution of large bodies.

Tetrapods or ‘four-limbed vertebrates’, have repeatedly returned to the oceans over the last 250 million years, and they come in many shapes and sizes, ranging from streamlined modern whales over 25 meters (82 feet) in length, to extinct plesiosaurs, with four flippers and extraordinarily long necks, and even extinct fish-shaped ichthyosaurs.

3D models of aquatic tetrapods. Credit: S. Gutarra Díaz

Dolphins and ichthyosaurs have similar body shapes, adapted for moving fast through water producing low resistance or drag. On the other hand, plesiosaurs, who lived side by side with the ichthyosaurs in the Mesozoic Era, had entirely different bodies. Their enormous four flippers which they used to fly underwater, and variable neck lengths, have no parallel among living animals. Some elasmosaurs had really extreme proportions, with necks up to 20 feet (6 meters) long. These necks likely helped them to snap up quick-moving fish, but were also believed to make them slower.

Until now, it has not been clear how shape and size influenced the energy demands of swimming in these diverse marine animals. Palaeobiologist Dr. Susana Gutarra Díaz of Bristol’s School of Earth Sciences and the National History Museum of London who led the research, explained: “To test our hypotheses, we created various 3D models and performed computer flow simulations of plesiosaurs, ichthyosaurs, and cetaceans. These experiments are performed on the computer, but they are like water tank experiments.”

Computer simulation of flow over the 3D model of an elasmosaur (plesiosaur). Credit: S. Gutarra Díaz

Dr. Colin Palmer, an engineer involved in the project said: “We showed that although plesiosaurs did experience more drag than ichthyosaurs or whales of equal mass because of their unique body shape, these differences were relatively minor. We found that when size is taken into account, the differences between groups became much less than the shape differences. We also show that the ratio of body length to diameter, which is widely used to classify these aquatic animals as more or less efficient, is not a good indicator of low drag.”

Elasmosauridae, often called elasmosaurs, is an extinct family of plesiosaurs. They had the longest necks of the plesiosaurs and lived from the Hauterivian to the Maastrichtian stages of the Cretaceous period. Their diet is believed to have mainly consisted of crustaceans and mollusks.

Dr. Gutarra Díaz said, “We were also particularly interested in the necks of elasmosaurs and so, we created hypothetical 3D models of plesiosaurs with various lengths of necks. Simulations of these models reveal that past a certain point, the neck adds extra drag, which potentially would make swimming costly. This ‘optimal’ neck limit lies around twice the length of the trunk of the animal.”

Dr. Benjamin Moon, another collaborator and expert on marine reptiles, continued: “When we examined a large sample of plesiosaurs modeled on really well-preserved fossils at their real sizes, it turns out that most plesiosaurs had necks below this high-drag threshold, within which neck can get longer or shorter without increasing drag. But more interestingly, we showed that plesiosaurs with extremely long necks also had evolved very large torsos, and this compensated for the extra drag!”

Dr. Tom Stubbs, another co-author summarised: “This study shows that, in contrast with prevailing popular knowledge, very long-necked plesiosaurs were not necessarily slower swimmers than ichthyosaurs and whales, and this is in part thanks to their large bodies. We found that in elasmosaurs, neck proportions changed really fast. This confirms that long necks were advantageous for elasmosaurs in hunting, but they could not exploit this adaptation until they became large enough to offset the cost of high drag on their bodies.”

Professor Mike Benton, also part of the research, commented: “Our research suggests that large aquatic animals can afford to have crazy shapes, as in the elasmosaurs. But there are limits: body sizes cannot get indefinitely large, as there are some constraints to very large sizes as well. The maximum neck lengths we observe, seem to balance benefits in hunting versus the costs of growing and maintaining such a long neck. In other words, the necks of these extraordinary creatures evolved in balance with the overall body size to keep friction to a minimum.”

Reference: “Large size in aquatic tetrapods compensates for high drag caused by extreme body proportions” by Susana Gutarra, Thomas L. Stubbs, Benjamin C. Moon, Colin Palmer and Michael J. Benton, 28 April 2022, Communications Biology.
DOI: 10.1038/s42003-022-03322-y

'Death shadow' dinosaur unearthed in Argentina

by Liliana Samuel

Argentine paleontologist Mauro Aranciaga with a graphic illustration of Maip macrothorax 

towering over a human.

Argentine paleontologists have announced the discovery of an apex-predator dinosaur that measured three stories from nose to tail and eviscerated its prey with sharp, curved claws.

The six-ton giant, the largest megaraptor unearthed to date, fed on smaller dinosaurs that it ripped to shreds with its talons before digging into their intestines, paleontologist Mauro Aranciaga told AFP.

It would have been the "apex predator" of its time, said Aranciaga—well deserving of its chilling scientific name "Maip macrothorax."

The first part, "Maip," is derived from an "evil" mythological figure of Patagonia's indigenous Aonikenk people.

The character was associated with "the shadow of the death" that "kills with cold wind" in the Andes mountains, according to a study reporting the find in the Nature journal Scientific Reports.

The second part, "macrothorax," refers to the enormous expanse of the creature's chest cavity—some 1.2 meters (3.9 feet) wide.

'Childhood dream'

The newly-identified monster measured nine to 10 meters in length, larger than any previously discovered type of megaraptor—a group of flesh-eating giants that once roamed what is now South America, according to Aranciaga's team.

It lived about 70 million years ago towards the end of the Cretaceous period in what was then a tropical forest, long before the Andes mountain range and glaciers that now define Patagonia.

Maip macrothorax lived about 70 million years ago towards the end of the Cretaceous period.

The killer reptile had two sharp, curved claws per front paw, each talon some 40 centimeters (15.7 inches) long.

Aranciaga, now 29, had the good fortune of finding the first piece of Maip on his first-ever professional expedition three years ago to Argentina's Santa Cruz province.

This led to months of meticulous digging, cleaning and classification of a large cache of bones: vertebrae as well as bits of rib, hip, tail and arm.

"When I lifted the vertebra and saw that it had the characteristics of a megaraptor, it was really a huge thrill," recalled Aranciaga.

The killer reptile had two sharp, curved claws per front paw that it used to eviscerate prey.

"Somehow I fulfilled my childhood dream... finding a new fossil and it turning out to be a megaraptor: the group in which I specialize," he told AFP.

Maip was one of the last megaraptors to inhabit Earth before the dinosaurs went extinct about 66 million years ago, according to Fernando Novas of the Argentine Museum of Natural Sciences' Laboratory of Comparative Anatomy.

It is also the southernmost megaraptor ever found, added Aranciaga, a doctoral fellow at Argentina's National Scientific and Technical Research Council (Conicet).Argentina puts 65-million-year-old dinosaur replica on display

More information: Alexis M. Aranciaga Rolando et al, A large Megaraptoridae (Theropoda: Coelurosauria) from Upper Cretaceous (Maastrichtian) of Patagonia, Argentina, Scientific Reports (2022). DOI: 10.1038/s41598-022-09272-z

Journal information: Scientific Reports 

© 2022 AFP

Rare fossil of ancient dog species discovered by paleontologists

by Pam Kragen

The partially excavated skull (facing to the right) of an Archeocyon, an ancient doglike

 species that lives in the area that’s now San Diego up to 28 million years ago.

 Credit: Cypress Hansen/San Diego Natural History Museum

Sometime around 14,000 years ago, the first humans crossed the Bering Strait to North America with canines, domesticated dogs they used for hunting, by their side.

But long before the canines arrived here, there were predatory doglike canid species who hunted the grasslands and forests of the Americas. A rare and nearly complete fossilized skeleton of one of these long-extinct species was recently discovered by paleontologists at the San Diego Natural History Museum.

This fossil belongs to a group of animals called Archeocyons, which means "ancient dog." It was embedded in two large chunks of sandstone and mudstone unearthed in 2019 from a construction project in the Otay Ranch area of San Diego County. The fossil dates to the late Oligocene epoch and is believed to be 24 million to 28 million years old.

While the fossilized remains are still awaiting further examination and identification by a canid researcher, its discovery has been a boon for the San Diego museum's scientists, including the curator of paleontology Tom Deméré, post-doctoral researcher Ashley Poust and curatorial assistant Amanda Linn.

Because the existing fossils in the museum's collection are incomplete and limited in number, the Archeocyons fossil will help the paleo team fill in the blanks on what they know about the ancient dog mammals that lived in the area we now know as San Diego tens of millions of years ago.

Did they walk on their toes like today's dogs? Did they burrow in the ground or live in trees? What food did they prey on and what animals preyed upon them? How did they relate to extinct doglike species that came before them? And, potentially, is this an entirely new undiscovered species? This new fossil is providing SDNHM scientists with a few more pieces of an incomplete evolutionary puzzle.

"It's like you've found a tree branch, but you need more branches to figure out what kind of tree it is," said Linn, who spent nearly 120 hours from December through February partially uncovering the fragile, and in some places, paper-thin skeleton from the rock. "As soon as you uncover the bones, they start to disintegrate ... I used a lot of patience, and a lot of glue."

Archeocyons fossils have been found in the Pacific Northwest and Great Plains states, but almost never in Southern California, where glaciers and plate tectonics have scattered, destroyed and buried deep underground many fossils from that period of history. The chief reason this Archeocyons fossil was found and made its way to the museum is a California law that requires paleontologists be onsite at major construction projects to spot and protect potential fossils for later study.

Pat Sena, the San Diego Natural History Museum's paleo monitor, was observing the rocks tailings in the Otay project nearly three years ago when he saw what looked like tiny white fragments of bone protruding from some excavated rock. He marked the rocks with a black Sharpie marker and had them moved to the museum, where scientific work soon ground to a halt for nearly two years because of the pandemic.

On Dec. 2, Linn started work on the two large rocks, using small carving and cutting tools and brushes to gradually pare away the layers of stone.

"Every time I uncovered a new bone, the picture got clearer," Linn said. "I'd say, 'Oh look, here's where this part matches up with this bone, here's where the spine extends to the legs, here's where the rest of the ribs are.' "

Poust said that once the fossil's cheekbone and teeth emerged from the rock, it became clear that it was an ancient canid species. In March, Poust was one of three international paleontologists who announced their discovery of a new saber-toothed catlike predator, Diegoaelurus, from the Eocene epoch. But where ancient cats had only flesh-tearing teeth, omnivorous canids had both cutting teeth in front to kill and eat small mammals and flatter molar-like teeth in the back of their mouths used to crush plants, seeds and berries. This mix of teeth and the shape of its skull helped Deméré identify the fossil as an Archeocyons.

The new fossil is fully intact except for a portion of its long tail. Some of its bones have been jumbled about, possibly as the result of earth movements after the animal died, but its skull, teeth, spine, legs, ankles and toes are complete, providing a wealth of information on the Archeocyons' evolutionary changes.

Poust said the length of the fossil's ankle bones where they would have connected to the Achilles tendons suggests the Archeocyons had adapted to chase its prey long distances across open grasslands. It's also believed that its strong, muscular tail may have been used for balance while running and making sharp turns. There are also indications from its feet that it possibly could have lived or climbed in trees.

Physically, the Archeocyons was the size of today's gray fox, with long legs and a small head. It walked on its toes and had nonretractable claws. Its more foxlike body shape was quite different from an extinct species know as Hesperocyons, which were smaller, longer, had shorter legs and resembled modern-day weasels.

While the Archeocyons fossil is still being studied and not on public display, the museum does have a large exhibit on its first floor that features fossils and a large mural of animals that lived here in San Diego's coastal region during ancient times. Poust said one the animals in the mural painted by artist William Stout, a foxlike creature standing over a freshly killed rabbit, is close to what the Archeocyons may have looked like.

Once the Archeocyons fossil was partially identified in February, Deméré had Linn stop work on the fossil, leaving it partially embedded in the rock. He didn't want to risk any damage to the intact skull until it can be further studied by a world-renowned carnivore researcher like Xiaoming Wang of the Natural History Museum of Los Angeles County.

"Nothing makes a curator happier than having visiting researchers to the collection," Deméré said. "Hopefully, someone comes along. A nearly complete skeleton like this can answer all sorts of questions, depending on who's interested."New sabre-tooth predator precedes cats by millions of years

©2022 The San Diego Union-Tribune.
Distributed by Tribune Content Agency, LLC.

Spacecraft navigation uses x-rays from dead stars

Peer-Reviewed Publication

UNIVERSITY OF ILLINOIS GRAINGER COLLEGE OF ENGINEERING

 

IMAGE: ZACH PUTNAM, PROFESSOR IN THE DEPARTMENT OF AEROSPACE ENGINEERING, THE GRAINGER COLLEGE OF ENGINEERING, UNIVERSITY OF ILLINOIS URBANA-CHAMPAIGN view more 

CREDIT: UNIVERSITY OF ILLINOIS URBANA-CHAMPAIGN

The remnants of a collapsed neutron star, called a pulsar, are magnetically charged and spinning anywhere from one rotation per second to hundreds of rotations per second. These celestial bodies, each 12 to 15 miles in diameter, generate light in the x-ray wavelength range. Researchers at The Grainger College of Engineering, University of Illinois Urbana-Champaign developed a new way spacecraft can use signals from multiple pulsars to navigate in deep space.

“We can use star trackers to determine the direction a spacecraft is pointing, but to learn the precise location of the spacecraft, we rely on radio signals sent between the spacecraft and the Earth, which can take a lot of time and requires use of oversubscribed infrastructure, like NASA’s Deep Space Network,” said Zach Putnam, professor in the Department of Aerospace Engineering at Illinois. 

“Using x-ray navigation eliminates those two factors, but until now, required an initial position estimate of the spacecraft as a starting point. This research presents a system that finds candidates for possible spacecraft locations without prior information, so the spacecraft can navigate autonomously.” 

“Also, our ground communication systems for deep space missions are overloaded right now,” he said. “This system would give spacecraft autonomy and reduce the dependency on the ground. X-ray pulsar navigation gets us around that and allows us to determine where we are, without calling.”

Putnam said because our atmosphere filters out all the x-rays, you have to be in space to observe them. The pulsars emit electromagnetic radiation that look like pulses because we measure the peak in the x-ray signals every time the pulsar spins around and points toward us—like the ray of light cast from the beacon on a lighthouse. 

“Each pulsar has its own characteristic signal, like a fingerprint,” he said. “We have records of the x-rays over time from the 2,000 or so pulsars and how they’ve changed over time.”

Much like the Global Positioning System, location can be determined from intersection of three signals. 

“The issue with pulsars is that they spin so fast that the signal repeats itself a lot,” he said. “By comparison, GPS repeats every two weeks. With pulsars, while there are an infinite number of possible spacecraft locations, we know how far apart these candidate locations are from each other.

“We are looking at determining spacecraft position within domains that have diameters on the order of multiple astronomical units, like the size of the orbit of Jupiter—something like a square with one billion miles on a side. The challenge we are trying to address is, how do we intelligently observe pulsars and fully determine all possible spacecraft locations in a domain without using an excessive amount of compute resources,” Putnam said.

The algorithm developed by graduate student Kevin Lohan combines observations from numerous pulsars to determine all the possible positions of the spacecraft. The algorithm processes all the candidate intersections in two dimensions or three dimensions.

“We used the algorithm to study which pulsars we should observe to reduce the number of candidate spacecraft locations within a given domain,” said Putnam. Results showed that observing sets of pulsars with longer periods and small angular separations could significantly reduce the number of candidate solutions within a given domain. 

The study, “Characterization of Candidate Solutions for X-Ray Pulsar Navigation,” written by Kevin G. Lohan and Zachary R. Putnam, is published in IEEE Transactions on Aerospace and Electronic Systems. DOI: 10.1109/TAES.2022.3152684

The research was funded in part by NASA.

CAPTION

Image Credit: X-ray: NASA/CXC/University of Amsterdam/N.Rea et al; Optical: DSS

---

JOURNAL

IEEE Transactions on Aerospace and Electronic Systems

DOI

10.1109/TAES.2022.3152684 

ARTICLE TITLE

Characterization of Candidate Solutions for X-Ray Pulsar Navigation

SETI Institute to recognize 4 undergraduate students at Drake Awards event

The SETI Forward Award encourages students to pursue careers in the search for life in the universe, the REU Award of Excellence honors an outstanding intern

Grant and Award Announcement

SETI INSTITUTE

 

IMAGE: YIWEI CHAI view more 

CREDIT: SETI INSTITUTE

May 3, 2022, Mountain View, CA – The SETI Institute named three undergraduate students as recipients of its SETI Forward Award: Yiwei Chai, Raffy Traas and Zoe Weiss. Mary Clare Greenlees will receive the REU Award of Excellence for her outstanding undergraduate research internship at the SETI Institute.

The SETI Forward Award recognizes outstanding undergraduates studying astrobiology and SETI research. SETI Forward provides scholarship funds to support the next generation of scientists and connects promising students with working researchers.

The REU Award for Excellence honors an outstanding SETI Institute intern. All four recipients will receive their awards at the 2022 Drake Awards ceremony on May 12, 2022.

“We think it’s crucial to encourage and enable the next generation of SETI scientists,” said Fritz Demopoulos, SETI Institute Trustee. “Without a doubt, our next great breakthroughs will emanate from science and engineering. Let’s lean forward and cheer from the sidelines.”

This year’s recipients pursued a range of research projects:

• Investigating the evolutionary transition from RNA enzymes which function in prebiotic conditions to more modern enzymes
• Developing a GNU Radio SETI search pipeline for the SETI Institute’s Allen Telescope Array 
• Using Cassini VIMS (visible and infrared mapping spectrometer) data to determine whether there is organic material (aromatic or aliphatic) present on Saturn’s satellite, Rhea
• Improving the Breakthrough Listen data processing pipeline by enabling it to leverage the computational power of Google Cloud Platform

The SETI Forward Award is supported by an endowed fund created by Lew Levy and Dane Glasgow and other donors to support undergraduate student research activities. Each summer, dozens of undergraduates complete internships alongside SETI and astrobiology research scientists – at organizations like the SETI Institute, U.C. Berkeley SETI Research Institute, Blue Marble Space Institute of Science, and many others. Too few of these students pursue science careers in SETI and astrobiology fields. SETI Forward seeks to bridge the gap between these internships and career opportunities in SETI science and astrobiology research.

“SETI Forward promotes the generational search for life outside Earth and encourages young people to join the search,” said Levy.

The SETI Forward Award will provide a travel stipend and reimbursement of expenses of approximately $1500 per award to:

• Assist undergraduate students with travel stipends to facilitate collaboration on SETI research at telescopes, universities, or other research facilities
• Fund undergraduate student travel expenses associated with presenting SETI research and astrobiology at scientific meetings, conferences, or similar events
• Provide undergraduate student scholarships to organizations engaged in SETI and astrobiology research to help obtain and nurture new talent in the field

“SETI research is taking ever greater strides towards answering one of the most profound and exciting questions in science,” said Simon Steel, Deputy Director, Carl Sagan Center. “We have the technology and, thanks to SETI Forward, the people to drive SETI into a new era of discovery. Congratulations to the SETI Forward recipients!”

SETI Forward Recipients

Yiwei Chai is a senior at the University of Pennsylvania, majoring in physics. She received the opportunity to undertake a research internship at the Berkeley SETI Research Center in the summer after her junior year. She worked with Dr. Wael Farah to develop a GNU Radio SETI search pipeline for the SETI Institute’s Allen Telescope Array (ATA). The internship helped her develop a greater appreciation for data-driven SETI approaches and the observation-to-analysis pipeline. She particularly enjoyed the week she spent on-site at the ATA in Hat Creek, CA, during which she also learned how to drive a buggy! This fall, Yiwei will be headed to Johns Hopkins University to begin a Ph.D. in Astronomy and Astrophysics, where she hopes to pursue questions about exoplanet populations and planetary habitability.

“My experience at the Berkeley SETI Research Center was wonderful,” said Chai. “I had the opportunity to learn a lot about how questions are asked and investigated in this field while also being exposed to various hard skills that are important to doing astronomy research in general. The internship also had a great balance of interesting work and interesting experiences—it’s not every summer that you get to visit two different observatories and see the instrumentation and the backend where all the professional observing and research happen! I came out of the summer with a better idea of what life as an astronomer might look like and can say that I am very excited to pursue that path.”

Raffy Traas is a 4th-year undergraduate studying astrophysics and applied math at the University of Wisconsin-La Crosse. He was adopted from the Philippines at the age of 2. He seeks to use these experiences to someday help advance the visions, missions, and goals of the recently founded Philippine Space Agency as a researcher and science communicator. As an intern at Breakthrough Listen under the mentorship of Steve Croft, Raffy improved its data processing pipeline by enabling it to leverage the computational power of Google Cloud Platform. Using this new processing infrastructure, he analyzed Breakthrough Listen’s initial observations of stars identified as potential Earth-like exoplanet hosts. The analysis culminated in a first-author publication in the Astronomical Journal. He plans to pursue graduate school to study cosmology but hopes to continue being involved with SETI and stay connected to the community.

CAPTION

Zoe Weiss

Zoe Weiss is a junior at Harvard University concentrating in Chemical and Physical Biology with a secondary in Mathematics. She is an undergraduate researcher in the Szostak Lab. Her research investigates the evolutionary transition from RNA enzymes functioning in prebiotic conditions to more modern enzymes. Her joint computational and experimental analyses collectively reveal how RNA functions are interconnected in sequence space and illuminate viable paths toward the evolutionary diversification of RNA enzymes. Originally from Atlanta, she has always been passionate about interdisciplinary research. After college, she hopes to pursue an MD/Ph.D. to become a quantitative physician-scientist.

“The SETI Forward award has inspired me to continue research at the intersection of chemistry and astrobiology.” said Weiss. “In my future studies, I hope to continue answering the “how” questions of the various paths evolution has taken, from the astronomy of raw materials to the mechanism of their development, to such complex, diverse, and mysterious forms of life.”

REU Award of Excellence recipient:

Mary Clare Greenlees is a senior at Barnard College and will be graduating with a Bachelor of Arts in Astrophysics in May 2022. Mary Clare participated in the 2021 SETI REU program, where she worked with Dr. Cristina Dalle Ore and Dr. Rachel Mastrapa. The project uses Cassini VIMS data to determine whether organic material (aromatic or aliphatic) is present on Saturn’s satellite, Rhea. This research is part of a survey of the icy satellites of Saturn with past targets such as Iapetus, Hyperion, and Phoebe. The broader implications of this work are to understand the presence of organic materials in the Saturn system and understand interactions between icy satellites.

“My summer at the SETI Institute cemented my desire to pursue a career in planetary science,” said Greenlees. “It was an invaluable experience where I met amazing scientists and fellow undergrads while furthering my skills as a researcher. I’m forever grateful to the SETI Institute for allowing me to become part of their community.”

The 2022 Drake Awards presentation will take place on May 12, 2022, at a public event held at SRI International in Menlo Park, CA. This year’s recipient is Dr. Shelley Wright, who is being for her innovative development and use of new instruments for optical SETI. The award presentation will also be live-streamed via Zoom for those unable to attend in person. Science Advisory Board member Timiebi Aganaba will host. Additional honorees will include recipients of the SETI Forward Award, which encourages future scientists to pursue careers in the search for life in the universe and the Carl Sagan Center Director’s Award, which honors outstanding achievement in astrobiology technology and exploration of life in the universe.

For more information about the 2022 Drake Awards, clic­k here.

About the SETI Institute
Founded in 1984, the SETI Institute is a non-profit, multi-disciplinary research and education organization whose mission is to lead humanity's quest to understand the origins and prevalence of life and intelligence in the universe and share that knowledge with the world. Our research encompasses the physical and biological sciences and leverages data analytics, machine learning, and advanced signal detection technologies. The SETI Institute is a distinguished research partner for industry, academia, and government agencies, including NASA and the National Science Foundation.

Contact information
Rebecca McDonald
Director of Communications
SETI Institute
mcdonald@seti.org

 

SwRI-led team finds younger exoplanets better candidates when looking for other Earths

Some exoplanets found thus far may be too old to support temperate, Earth-like climates

Peer-Reviewed Publication

SOUTHWEST RESEARCH INSTITUTE

 

IMAGE: AN SWRI-LED STUDY SUGGESTS THAT HOST-STAR AGE AND RADIONUCLIDE ABUNDANCE WILL HELP DETERMINE BOTH AN EXOPLANET’S HISTORY AND ITS CURRENT LIKELIHOOD OF BEING TEMPERATE TODAY. FOR EXAMPLE, THE RED DWARF STAR TRAPPIST-1 IS HOME TO THE LARGEST GROUP OF ROUGHLY EARTH-SIZED PLANETS EVER FOUND IN A SINGLE STELLAR SYSTEM WITH SEVEN ROCKY SIBLINGS INCLUDING FOUR IN THE HABITABLE ZONE. BUT AT AROUND 8 BILLION YEARS OLD, THESE WORLDS ARE ROUGHLY 2 BILLION YEARS OLDER THAN THE MOST OPTIMISTIC DEGASSING LIFETIME PREDICTED BY THIS STUDY AND UNLIKELY TO SUPPORT A TEMPERATE CLIMATE TODAY. view more 

CREDIT: NASA/JPL-CALTECH

SAN ANTONIO — May 3, 2022 — As the scientific community searches for worlds orbiting nearby stars that could potentially harbor life, new Southwest Research Institute-led research suggests that younger rocky exoplanets are more likely to support temperate, Earth-like climates.

In the past, scientists have focused on planets situated within a star’s habitable zone, where it is neither too hot nor too cold for liquid surface water to exist. However, even within this so-called “Goldilocks zone,” planets can still develop climates inhospitable to life. Sustaining temperate climates also requires a planet have sufficient heat to power a planetary-scale carbon cycle. A key source of this energy is the decay of the radioactive isotopes of uranium, thorium and potassium. This critical heat source can power a rocky exoplanet’s mantle convection, a slow creeping motion of the region between a planet’s core and crust that eventually melts at the surface. Surface volcanic degassing is a primary source of CO2 to the atmosphere, which helps keep a planet warm. Without mantle degassing, planets are unlikely to support temperate, habitable climates like the Earth’s.

“We know these radioactive elements are necessary to regulate climate, but we don’t know how long these elements can do this, because they decay over time,” said Dr. Cayman Unterborn, lead author of an Astrophysical Journal Letters paper about the research. “Also, radioactive elements aren’t distributed evenly throughout the Galaxy, and as planets age, they can run out of heat and degassing will cease. Because planets can have more or less of these elements than the Earth, we wanted to understand how this variation might affect just how long rocky exoplanets can support temperate, Earth-like climates.”

Studying exoplanets is challenging. Today’s technology cannot measure the composition of an exoplanet’s surface, much less that of its interior. Scientists can, however, measure the abundance of elements in a star spectroscopically by studying how light interacts with the elements in a star’s upper layers. Using these data, scientists can infer what a star’s orbiting planets are made of using stellar composition as a rough proxy for its planets.

“Using host stars to estimate the amount of these elements that would go into planets throughout the history of the Milky Way, we calculated how long we can expect planets to have enough volcanism to support a temperate climate before running out of power,” Unterborn said. “Under the most pessimistic conditions we estimate that this critical age is only around 2 billion years old for an Earth-mass planet and reaching 5–6 billion years for higher-mass planets under more optimistic conditions. For the few planets we do have ages for, we found only a few were young enough for us to confidently say they can have surface degassing of carbon today, when we’d observe it with, say, the James Webb Space Telescope.”

This research combined direct and indirect observational data with dynamical models to understand which parameters most affect an exoplanet’s ability to support a temperate climate. More laboratory experiments and computational modeling will quantify the reasonable range of these parameters, particularly in the era of the James Webb Space Telescope, which will provide more in-depth characterization of individual targets. With the Webb telescope, it will be possible to measure the three-dimensional variation of exoplanet atmospheres. These measurements will deepen the knowledge of atmospheric processes and their interactions with the planet’s surface and interior, which will allow scientists to better estimate whether a rocky exoplanet in habitable zones is too old to be Earth-like.

“Exoplanets without active degassing are more likely to be cold, snowball planets,” Unterborn said. “While we can’t say the other planets aren’t degassing today, we can say that they would require special conditions to do so, such as having tidal heating or undergoing plate tectonics. This includes the high-profile rocky exoplanets discovered in the TRAPPIST-1 star system. Regardless, younger planets with temperate climates may be the simplest places to look for other Earths.”

The Astrophysical Journal Letters paper describing this research is titled “Mantle Degassing Lifetimes through Galactic Time and the Maximum Age Stagnant-lid Rocky Exoplanets can Support Temperate Climates” and can be accessed at https://doi.org/10.3847/2041-8213/ac6596.

For more information, visit https://www.swri.org/planetary-science.

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JOURNAL

The Astrophysical Journal Letters

DOI

10.3847/2041-8213/ac6596 

METHOD OF RESEARCH

Commentary/editorial

SUBJECT OF RESEARCH

Not applicable

ARTICLE TITLE

Mantle Degassing Lifetimes through Galactic Time and the Maximum Age Stagnant-lid Rocky Exoplanets can Support Temperate Climates

ARTICLE PUBLICATION DATE

3-May-2022