Solar Storms Scientists amp up efforts to protect Earth from what the sun throws at us - February 27, 2021
←
→
Page content transcription
If your browser does not render page correctly, please read the page content below
COVID-19 Lessons From Colleges | Impostor Fossils
MAGAZINE OF THE SOCIETY FOR SCIENCE s FEBRUARY 27, 2021
Solar
Storms Scientists amp up efforts
to protect Earth from what
the sun throws at us
cover.indd 1 2/10/21 1:52 PM
Cognitive Behavioral
Therapy for Daily Life
Taught by Professor Jason M. Satterfield
TIME O
ED F UNIVERSITY OF CALIFORNIA, SAN FRANCISCO
IT
FE
LECTURE TITLES
LIM
70%
R
1. A CBT Toolbox: Toward Wise Living
2. Laying a Foundation: Assessments and Goals
off 3. Behavioral Activation: Potent Mood Boosters
1
R
H
O
DE 4. Advanced Behavioral Techniques
C
R BY M AR
5. Capturing Thoughts and Making Connections
6. Cognitive Restructuring and Thought Records
7. Worry, Rumination, and Sticky Thoughts
8. Digging Deeper: Rules and Core Beliefs
9. Toolbox in Action: Stress and Assertiveness
10. Understanding and Managing Emotions
11. Key Steps to Solving Problems
12. Grief, Sadness, and Depression
13. Panic Attacks and Anxiety
14. Addiction and Pain Medications
15. Embracing Imperfection
16. Beating Procrastination
17. Soothing Rejection, Promoting Connection
18. Early Childhood Trauma and Neglect
19. Managing Chronic Disease
20. Coping with Chronic Pain
21. How to End Insomnia and Finally Sleep
A Powerful Way to Take 22. CBT for the Beginning of the End of Life
23. Expanding CBT with Technology
Control of Your Life 24. Reclaiming and Rewriting Our Stories
Why is life so challenging? Life presents daily challenges such as difficult
coworkers, chronic pain, marital conflicts, grief, parenting issues, and Cognitive Behavioral Therapy for Daily Life
Course no. 9661 | 24 lectures (30 minutes/lecture)
more. For many people, those challenges can spiral into streams of
spontaneous, negative thoughts about themselves, the world, and their
future. While you can’t change the challenges, the tools of cognitive
behavioral therapy (CBT) can change how you think about them and SAVE UP TO $190
help you best access your rational and emotional selves.
In these 24 compelling half-hour lessons of Cognitive Behavioral DVD $269.95 NOW $79.95
Therapy for Daily Life, Professor Jason Satterfield will help you build Instant Video $234.95 NOW $59.95
your CBT toolbox—showing you an effective way to change your stories +$10 Shipping & Processing (DVD only)
and Lifetime Satisfaction Guarantee
and change your life. You will learn about both cognitive and behavioral
Priority Code: 192645
tools, each of which will help you move toward better emotion
regulation and functional improvements. These tools and skills will also
help you learn to create and savor positive experiences that bring greater For over 30 years, The Great Courses has brought
happiness, satisfaction, and meaning to your life. the world’s foremost educators to millions who want
to go deeper into the subjects that matter most. No
Offer expires 03/01/21 exams. No homework. Just a world of knowledge
available anytime, anywhere. Download or stream
THEGREATCOURSES.COM/4 SN to your laptop or PC, or use our free apps for iPad,
iPhone, Android, Kindle Fire, or Roku. Over 800
1-800-832-2412 courses available at www.TheGreatCourses.com.
_C2.indd 2 2/10/21 9:26 AM
VOL. 199 | NO. 4
Features
16 Solar Storm Preparedness
COVER STORY There’s got to be a better way to
predict when the sun is going to send a burst of
charged particles our way. Communication and
transportation systems and the power grid depend
on it. By Ramin Skibba
22 COVID-19 on Campus
Many U.S. colleges opened for fall semester last year,
throwing a mixed bag of testing, surveillance and
social distancing at students and staff. Did it keep the
16
coronavirus at bay? By Betsy Ladyzhets
News
6 Earth’s early fossil record Naked mole-rat colonies 11 An upwelling of rock
may be filled with have distinctive dialects beneath the Atlantic
microbe mimics Ocean may be driving
9 Thumbs with humanlike
continents apart
7 An antidepressant shows dexterity evolved by
promise in preventing 2 million years ago 12 The Milky Way basks
severe cases of COVID-19 in a glow of extremely
10 The tuatara is the first
8 Ancient giant worms may vertebrate discovered energetic gamma rays 32
have burrowed into the to have two sets of
Scientists bake
seafloor to ambush prey mitochondrial DNA pulverized meteorites
to re-create exoplanet
Departments
atmospheres 2 EDITOR’S NOTE
13 Some spiders have their 4 NOTEBOOK
own version of a pulley to Knitting’s knotty math
lift massive meals inspires a physicist;
a plant-based robot
14 Skink-biting ticks may
KATIE ASKEW/CAJAL EMBROIDERY PROJECT; BERNARD SPRAGG. NZ/FLICKR
gets a grip
help explain why Lyme
disease is uncommon 29 REVIEWS & PREVIEWS
Gross science deserves
in the U.S. South
your attention
15 News in Briefs
FROM TOP: NASA GODDARD SPACE FLIGHT CENTER;
31 FEEDBACK
An ancient Egyptian
mummy wore a shell 32 SCIENCE VISUALIZED
of mud Embroiderers stitch
iconic images of brain cells
Diamond doesn’t
succumb to high pressure
COVER A bright cloud of
particles blew out from
Gestational diabetes
the sun in 2013. Activity in
may increase a woman’s the current solar cycle is
risk of having hardened expected to peak in 2025.
10 SDO/Goddard/NASA/Flickr
arteries later in life
www.sciencenews.org | February 27, 2021 1
toc.indd 1 2/10/21 1:57 PM
EDITOR’S NOTE
When a naked mole-rat
PUBLISHER Maya Ajmera
EDITOR IN CHIEF Nancy Shute
EDITORIAL
meets a sneaky sea worm EDITOR , SPECIAL PROJECTS Elizabeth Quill
NEWS DIRECTOR Macon Morehouse
DIGITAL DIRECTOR Kate Travis
FEATURES EDITOR Cori Vanchieri
What do naked mole-rats and ancient sea worms have in MANAGING EDITOR , MAGAZINE Erin Wayman
DEPUTY NEWS EDITOR Emily DeMarco
common? Quite a bit, which is why they’re sharing real ASSOCIATE NEWS EDITOR Ashley Yeager
ASSOCIATE EDITOR Cassie Martin
estate on Page 8 of this issue. ASSOCIATE DIGITAL EDITOR Helen Thompson
AUDIENCE ENGAGEMENT EDITOR Mike Denison
One of my favorite parts of editing Science News is read- ASTRONOMY Lisa Grossman
ing page proofs, one of the last steps in the long magazine BEHAVIORAL SCIENCES Bruce Bower
BIOMEDICAL Aimee Cunningham
production process. Even though I know what’s going into the magazine and EARTH AND CLIMATE Carolyn Gramling
LIFE SCIENCES Susan Milius
have read the articles before, it’s still like opening up a surprise gift to see the MOLECULAR BIOLOGY, SENIOR WRITER Tina Hesman Saey
NEUROSCIENCE Laura Sanders
pages come together. It’s the work of dozens of people, a process that starts PHYSICS Emily Conover
SOCIAL SCIENCES Sujata Gupta
when writers pitch ideas for news and feature articles. News stories get pub- STAFF WRITERS Erin Garcia de Jesus, Jonathan Lambert,
Maria Temming
lished first on the Science News website, and there are many more than we can EDITORIAL ASSISTANT Aina Abell
CONTRIBUTING CORRESPONDENTS
fit in a magazine. So it’s up to managing editor Erin Wayman to choose the ones Laura Beil, Tom Siegfried, Alexandra Witze
that will go into print. She looks for the most important or intriguing science DESIGN
CHIEF DESIGN OFFICER Stephen Egts
of the previous two weeks, and aims for reporting across the fields of science, DESIGN DIRECTOR Erin Otwell
ART DIRECTOR Tracee Tibbitts
from artificial intelligence to zoology. ASSISTANT ART DIRECTOR Chang Won Chang
Articles that make the cut often either help answer a question that scientists SCIENCE NEWS FOR STUDENTS
have worked to solve for a long time, or alert us to something that’s surprising EDITOR Janet Raloff
MANAGING EDITOR Sarah Zielinski
and counterintuitive. STAFF WRITER Bethany Brookshire
WEB PRODUCER Lillian Steenblik Hwang
For Page 8, Wayman picked a report on how naked mole-rats use distinctive SOCIETY FOR SCIENCE
dialects to communicate with mole-rats within their social group. “It may seem PRESIDENT AND CEO Maya Ajmera
CHIEF OF STAFF Rachel Goldman Alper
surprising, but they’re highly social animals, so they would need a way to com- CHIEF MARKETING OFFICER Kathlene Collins
CHIEF PROGRAM OFFICER Michele Glidden
municate,” she says. I was surprised and charmed by the notion of these mostly CHIEF, EVENTS AND OPERATIONS Cait Goldberg
CHIEF COMMUNICATIONS OFFICER Gayle Kansagor
blind critters chirping away in their burrows. CHIEF ADVANCEMENT OFFICER Bruce B. Makous
CHIEF TECHNOLOGY OFFICER James C. Moore
Wayman then paired the chatty naked mole-rats with a story of fossils that CHIEF FINANCIAL OFFICER Dan Reznikov
suggest giant worms may have dug tunnels in the seafloor millions of years ago, BOARD OF TRUSTEES
CHAIR Mary Sue Coleman
springing forth from them to nab unsuspecting prey. While present-day VICE CHAIR Martin Chalfie TREASURER Hayley Bay Barna
SECRETARY Paul J. Maddon AT LARGE Christine Burton
hairless rodents and ancient predatory worms may not seem to have much in MEMBERS Craig R. Barrett, Adam Bly, Tessa M. Hill,
Tom Leighton, Alan Leshner, W.E. Moerner, Dianne K. Newman,
common, Wayman says she sees a pattern. “You’re looking at behavior today Thomas F. Rosenbaum, Gideon Yu, Feng Zhang,
and in the past, which gives insights into animal behavior.” Maya Ajmera, ex officio
ADVERTISING AND SUBSCRIBER SERVICES
And for more connections between present and past, Page 9 features a story ADVERTISING Daryl Anderson
suggesting that hominids may have developed a specialized thumb muscle SCIENCE NEWS IN HIGH SCHOOLS Anna Rhymes
PERMISSIONS Maxine Baydush
quite early on, one that helps give humans today our firm grip and uniquely Science News
1719 N Street NW, Washington, DC 20036
adaptable hands. “It’s amazing that the manual dexterity that we rely on has (202) 785-2255
been around for almost 2 million years, even before we were human,” Wayman Subscriber services:
says. Perhaps we have that muscle to blame for humankind’s newly acquired E-mail subscriptions@sciencenews.org
Phone (800) 552-4412 in the U.S. or
talent for texting. (937) 610-0240 outside of the U.S.
Web www.sciencenews.org/join
Whether it’s clueing our readers into gossipy naked mammals or ancient For renewals, www.sciencenews.org/renew
thumb muscles, we put a great deal of care into choosing articles that not only Mail Science News, PO Box 292255, Kettering, OH
45429-0255
tell you something interesting or fun about the world, but also something Editorial/Letters: feedback@sciencenews.org
that’s relevant to life today. That includes our continuing in-depth coverage Science News in High Schools: snhs@societyforscience.org
Advertising/Sponsor content: ads@societyforscience.org
of the coronavirus pandemic: Page 7 has a fascinating article explaining how a Science News (ISSN 0036-8423) is published 22 times per
common antidepressant may help fend off serious illness from COVID-19. year, bi-weekly except the first week only in May and October
and the first and last weeks only in July by the Society for
I hope you enjoy reading the magazine as much as we love creating it for Science & the Public, 1719 N Street, NW, Washington, DC
20036.
you. And if you need more great science journalism while awaiting the next Subscribe to Science News: Subscriptions include 22 issues
issue, we’ve got plenty more for you at www.sciencenews.org. of Science News and full access to www.sciencenews.org and
cost $50 for one year (international rate of $68 includes
— Nancy Shute, Editor in Chief extra shipping charge).
Subscribe www.sciencenews.org/subscription
SOCIETY FOR SCIENCE
Single copies are $3.99 (plus $1.01 shipping and handling).
Preferred periodicals postage paid at Washington, D.C., and
Society for Science & the Public is a 501(c)(3) nonprofit membership organization founded in 1921. The Society seeks to
an additional mailing office.
promote the understanding and appreciation of science and the vital role it plays in human advancement: to inform, edu-
cate, inspire. Learn more at societyforscience.org. Copyright © 2021 by Society for Science & the Public. Title registered Postmaster: Send address changes to Science News,
as trademark U.S. and Canadian Patent Offices. Republication of any portion of Science News without written permission of PO Box 292255, Kettering, OH 45429-0255. Two to six
the publisher is prohibited. For permission to photocopy articles, contact permissions@sciencenews.org. Sponsor content weeks’ notice is required. Old and new addresses, including
and advertising appearing in this publication do not constitute endorsement of its content by Science News or the Society. zip codes, must be provided.
2 SCIENCE NEWS | February 27, 2021
ednote.indd 2 2/10/21 10:50 AM
CTK Bio Canada Develops Bioplastic Resin
Designed to Break Down in Soil and Seawater
CTK Bio Canada has developed a new bioplastic The Company’s materials are designed to overcome a
resin designed to biodegrade by both industrial critical barrier in the bioplastics space — the ability to
and home composting, as well as in unmanaged degrade in water. While increased use of bioplastics are
environments like soil and seawater. The Company a positive sign for the environment, Shum and Park knew
is now undertaking detailed experimental trials with that too much of it was still ending up in rivers and oceans
academic partners to validate its technology ahead where they couldn’t easily biodegrade. CTK Bio Canada’s
of anticipated commercial rollout in 2022. materials are designed to break down not only if disposed
of in the green bin, but also if they end up discarded to
Park and Shum developed their technology in the environment. The materials should degrade only to
partnership with Profs. Zachary Hudson and nontoxic byproducts, while also remaining compatible with
Emily Cranston, experts in plant-based materials equipment for manufacturing traditional plastics.
technology at the University of British Columbia.
Hudson holds the Canada Research Chair in Most importantly, the team believes they can achieve
Sustainable Chemistry, and Cranston is currently these milestones in materials science while keeping
the President’s Excellence Chair in Forest Bio- costs competitive with petroleum-based plastics. Initial
Products. Once the formulation had been developed, prototyping has already been completed on a series
prototyping began with the Polymer Materials of plastic parts and films, with detailed testing planned
and Manufacturing group at McMaster University; in 2021 to validate the material’s degradability. The
Heera Marway, Vladimir Gritsichine, Profs. Michael Company has also released a white paper on its website
Thompson and Li Xi. describing the formulation and design in more detail.
WANT TO LEARN MORE?
Visit www.ctkcanada.com or contact Daniel Shum, Chief Operating Officer at daniel.shum@ctkcanada.com
ADVE RTISE M E N T
_p3.indd 3
MAR_002_21_B.indd 1 2/10/21
1/29/2021 9:27
2:54:30 PMAM
NOTEBOOK
THE SCIENCE LIFE
A physicist is unraveling knitting’s math secrets
Physicist Elisabetta Matsumoto is an avid principles have helped explain how DNA
knitter and has been since taking up the folds and unfolds and how a molecule’s
hobby as a child. During graduate school makeup and distribution in space impart
at the University of Pennsylvania in 2009, it with physical and chemical character-
Excerpt from the Matsumoto came across an unusually istics (SN: 9/15/18, p. 32). Matsumoto is
March 6, 1971 knotty stitch while knitting a pattern for a using knot theory to understand how each
issue of Science News
red dragon. “I have books with thousands stitch entangles with its neighbors. “The
of different stitch patterns, but the one types of stitches, the differences in their
50 YEARS AGO in the red dragon wall hanging was one I geometries as well as the order in which
had never seen,” she says. you put those stitches
Whale That got her thinking about together into a textile may
protection the geometry of stitches determine [the fabric’s]
Whaling by the single and, eventually, led her to properties,” she says.
remaining United States study the mathematics of Making tiny changes,
whaling firm, the Del Monte knitting. such as altering a couple
Fishing Co. of San Francisco, There are two types of of crossings in a knot,
will probably end as the stitches — knit and purl — could have a huge impact
result of a proposal … to ter- and they can be combined on the mechanics of the
minate licensing for hunting into 100 or so basic pat- textile. For instance, a fab-
the finback, sei and sperm terns, Matsumoto says. By ric made of solely knits or
whales. The three were varying stitch combina- purls tends to curl at the
placed on the endangered tions within patterns, a edges. But combine the
species list last year. knitter can alter the elas- Physicist Elisabetta Matsumoto two stitch types together
ticity, mechanical strength hopes to create a dictionary of in alternating rows or col-
UPDATE: During the and 3-D structure of the stitches that could be used to umns, and the fabric lays
manipulate material properties.
20th century, humans killed resulting fabric. Yarn on flat. And despite looking
FROM TOP: COURTESY OF E. MATSUMOTO; ROMIRI/ISTOCK/GETTY IMAGES PLUS
an estimated 2.9 million large its own isn’t very elastic. But when knit- nearly identical, these knitted fabrics
whales. In response to those ted, the yarn gives rise to fabric that can have varying degrees of stretchiness,
losses, countries eventually stretch by more than twice its length while Matsumoto and grad student Shashank
took action. Legislation passed the yarn itself barely stretches. Markande reported in July in the Bridges
in the 1970s effectively put a Matsumoto, now at Georgia Tech in 2020 Conference Proceedings.
stop to commercial whaling in Atlanta, is teasing out the mathematical Matsumoto’s team is now training a
the United States. A worldwide rules that dictate how stitches impart such computer program to predict the mechani-
FROM TOP: © BAT CONSERVATION INTERNATIONAL; W. LI ET AL/NATURE ELECTRONICS 2021
ban followed in 1986, though properties to fabrics. She hopes to develop cal properties of fabrics, based on yarn
some countries including a catalog of stitch types, their combina- properties, mathematical stitch details and
Japan, Norway and Iceland tions and the resulting fabric properties. final knitted structures. These predictions
continue to hunt the animals. Knitters, scientists and manufacturers could someday help tailor materials for
The bans have helped whale could all benefit from a dictionary of knits, specific applications — from scaffolds for
populations recover, but not she says. growing human tissue to wearable smart
enough to move these three Matsumoto’s research builds on knot clothing (SN: 6/9/18, p. 18) — and perhaps
species off the U.S. endangered theory, a set of mathematical princi- solve knotty problems of everyday life.
species list. Sperm whales have ples that define how knots form. These — Lakshmi Chandrasekaran
rebounded to an estimated
450,000 individuals, sei whales Researchers are trying to understand the math behind
number around 50,000 and how stitches alter the elasticity, mechanical strength
and 3-D structure of knitted fabrics.
finback whales have reached
about 100,000. Ship collisions
now pose a bigger threat to
the mammals than commercial
SN Online: 7/29/14).
whaling (SN
4 SCIENCE NEWS | February 27, 2021
notebook.indd 4 2/10/21 12:45 PM
A newly discovered SCIENCE STATS
bat species from
Guinea’s Nimba COVID-19 worsened
Mountains is a great
reminder that there’s students’ mental health
flashy coloring in the The coronavirus pandemic has caused
bat world.
the mental health of U.S. college stu-
dents to plummet, researchers report
INTRODUCING January 7 in PLOS ONE. Environmen-
h tal psychologist Matthew Browning of
A new bat species is always ready for Halloween Clemson University in South Carolina
Bats, better known for their mousy looks, can have a colorful side. A new and colleagues surveyed more than
species, discovered when two bats were caught at an abandoned mining tunnel 2,500 students from seven public uni-
in western Africa, sports showy orange and black swaths of fur. versities across the United States last
The species, dubbed Myotis nimbaensis, is “just gorgeous,” says mammalogist spring. About 85 percent of those sur-
Nancy Simmons of the American Museum of Natural History in New York City. veyed experienced high to moderate
Orange fur on the bat’s back contrasts with black patches of wing membranes. levels of emotional distress arising from
But bright fluff is not what sets this species apart: Three other Myotis species in the pandemic, the team found. Students
Africa are similarly flashy. Rather less visible traits, from details of its echoloca- most at risk of mental health chal-
tion calls to hidden striping in its fur, peg M. nimbaensis as unusual, Simmons lenges included women, Asian people,
and colleagues report online January 13 in American Museum Novitates. students under age 25, students in poor
Researchers discovered the new species the old-fashioned way — in a remote health, those who knew somebody with
- forest at night with keen eyes studying real animals. When Simmons’ team COVID-19 and lower-income students.
collected the first bat, near the mouth of an abandoned tunnel for mineral explo- Spending eight or more hours in front
ration in Guinea’s section of the Nimba Mountains, the dramatic beast wasn’t of computer, smartphone or TV screens
obviously a new species. While most kinds of bats are various shades of brown also increased the risk. — Sujata Gupta
85
and black, bats here and there around the world can be yellow, fluffball white or
coppery red. And there was the matter of Africa’s other orange Myotis species.
M. nimbaensis, named for its mountainous habitat, differs genetically from
near kin about as much as humans differ from gorillas, Simmons says. Differ-
~
FROM TOP: COURTESY OF E. MATSUMOTO; ROMIRI/ISTOCK/GETTY IMAGES PLUS
ences also show up in teeth and other anatomy. One way to tell the new species percent
apart, for instance, is from the proportions of secret stripes on the hairs in orange Proportion of U.S. college students
surveyed who experienced moderate
fur patches. The bottom third of each hair is black. Then comes a creamy white to high levels of emotional distress
s middle third before the hair turns pumpkin at the tip. — Susan Milius early in the pandemic
- HOW BIZARRE
FROM TOP: © BAT CONSERVATION INTERNATIONAL; W. LI ET AL/NATURE ELECTRONICS 2021
d
A robot arm toting a Venus flytrap
has a gentle but firm grasp
A new robotic grabber is ripped straight from the plant
world. The device, made with a severed piece of a Venus
flytrap, can grasp tiny, delicate objects, researchers report
January 25 in Nature Electronics.
Normally, the carnivorous Dionaea muscipula scores a In laboratory experiments, a robotic grabber made with part of a Venus
meal when an unsuspecting prey touches delicate hairs on flytrap grasped a slowly moving one-gram weight.
one of the plant’s jawlike leaves, triggering the trap to snap
shut. By sticking electrodes to the leaves and applying a be damaged by clunky, rigid graspers (SN: 4/13/19, p. 5), the
small electric voltage, researchers designed a method to researchers say. So, Li’s team attached a piece of a flytrap to
force Venus flytraps to close. Even when cut from the plant, a robotic arm and used a smartphone app to control the trap.
the leaves retained the ability to shut upon command for up In experiments, the grabber clutched a piece of wire half a
to a day, say materials scientist Wenlong Li and colleagues at millimeter in diameter. The dismembered plant also caught
Nanyang Technological University in Singapore. a slowly moving one-gram weight. One drawback: The traps
Integrating soft, flexible plant material into robotics take hours to reopen, so this bot had better make the catch
could aid in picking up fragile objects that would otherwise on the first try. — Emily Conover
Watch the robotic Venus flytrap grabber in action at bit.ly/SN_RoboFlytrap www.sciencenews.org | February 27, 2021 5
notebook.indd 5 2/10/21 12:45 PM
News
2 µm
LIFE & EVOLUTION
Many early fossils Crystalline objects
known as biomorphs,
may be impostors such as these sphere-
shaped structures, are made
nonbiologically through
Abiotic objects that resemble chemical reactions and can
microbes preserve more easily closely resemble microfossils.
BY CAROLYN GRAMLING mixing sulfides with organic matter, and a better chance of being pseudofossils,
When it comes to finding fossils of we started forming these objects,” she rather than actual fossils, the team says.
very ancient microbial life — whether says. “We thought they were formed by The idea that living creatures are
on Earth or on other worlds, such as the bacteria, because they looked so bio- harder to preserve makes sense, says
Mars — the odds are just not in our favor. logical. But then we realized they were Sean McMahon, an astrobiologist at the
Microbial life-forms are much less forming in laboratory tubes that hap- University of Edinburgh. “Biomass does
likely to become safely fossilized in rocks pened to have no bacteria in them at all.” tend to break down quite quickly.” In
compared with nonbiological structures That led her to wonder about such pro- fact, scientists have known for centuries
that happen to mimic their shapes. That cesses happening in the rocks themselves. that certain chemical reactions can act
finding suggests that Earth’s earliest So she and others examined what would as “gardens” that “grow” mineral objects
rocks may contain abundant fakers — happen if they tried to re-create the early that twist into tubes, sprout branches or
minuscule objects masquerading as formation stages of chert, a compact, otherwise mimic life. “There’s a compla-
fossilized evidence of life, researchers silica-rich rock common on the early cency about it, a misconception that we
report online January 28 in Geology. Earth. “Microfossils are often found in kind of know all this and it’s already been
The finding is “at the very least a cau- chert formations,” says study coauthor dealt with,” McMahon says.
tionary tale,” says geomicrobiologist Julie Christine Nims, a geobiologist now at Strategies to deal with this conundrum
Cosmidis of the University of Oxford. the University of Michigan in Ann Arbor. have included looking for certain chemi-
Tiny, often enigmatic structures found Chert forms when silica precipitates cal compounds in a potential fossil or for
in rocks dating back more than 2.5 billion out of water and accumulates, eventu- structures, such as mound-shaped stro-
years can offer hints of the planet’s ally hardening into rock. Cosmidis, Nims matolites, that are thought to be uniquely
earliest life. The hunt for ever-more- and colleagues added sulfur-containing formed or modified by the presence of life
ancient signs of life has sparked intense bacteria called Thiothrix to solidifying (SN: 11/10/18, p. 12). Those criteria are
debate — in part because the farther back chert to see what might happen dur- the product of decades of field studies,
in time you go, the harder it is to interpret ing actual fossilization. To other chert through which scientists have amassed a
tiny squiggles, filaments and spheres in samples, they added sulfur-containing reference dataset of fossil structures to
the rock (SN: 1/18/20, p. 5). One reason “biomorphs,” bacteria-shaped spheres compare new finds against.
is that the movements of Earth’s tectonic and filaments made of tiny crystals. What’s lacking is a similarly rich data-
plates over time can squeeze and cook the Nanoparticles of silica encrusted the set for how such structures might form in
rocks, deforming and chemically altering bacteria and the biomorphs, Nims says. the absence of life, McMahon says. This
tiny fossils, perhaps beyond recognition. But after a week or so, the bacteria started study highlights that attempts “to define
But an even more pernicious problem to deform, their cells deflating from cyl- criteria for recognizing true fossils in very
is that such filaments or spheres may not inders into flattened, unrecognizable ancient rocks are premature, because we
be biological in origin at all. Increasingly, ribbons as the sulfur inside the cells dif- don’t yet know enough about how non-
scientists have found that nonbiological fused out and reacted with the silica biological processes mimic true fossils.”
chemical processes can create similar outside the cells, forming new minerals. It’s an increasingly urgent problem
shapes, suggesting the possibility of “false The biomorphs, on the other hand, with rising stakes, as NASA’s Persever-
positives” in the fossil record. “had this impressive resiliency,” she says. ance rover will search for traces of life in
One such discovery led to the new They also lost sulfur to the surrounding ancient rocks on Mars, McMahon adds.
study, Cosmidis says. A few years ago, she solution but kept their silica crust. That “Paleontologists and Mars exploration
and others were trying to grow bacteria endurance suggests that enigmatic struc- scientists should take [this study] very
C. NIMS
and make them produce sulfur. “We were tures found in the early rock record have seriously.” s
6 SCIENCE NEWS | February 27, 2021
fossils.indd 6 2/10/21 1:47 PM
BODY & BRAIN workers and offered a 14-day course of
Antidepressant could treat COVID-19 the drug at no cost to those who could
safely take it. The group was predomi-
Fluvoxamine prevents mild cases from worsening, data suggest nantly male and Latino, and 30 percent
had chronic medical problems such as
BY ESTHER LANDHUIS supported randomized trial in which diabetes or high blood pressure.
The antidepressant fluvoxamine could none of 80 newly diagnosed COVID-19 Sixty-five people chose to take the
prevent people from getting seriously patients assigned to a two-week course drug, and 48 declined. The treatment
ill with COVID-19, curbing hospitaliza- of fluvoxamine became seriously ill. By group had a higher proportion of Latinos
tions, new data show. comparison, six of 72 patients, or 8.3 per- and tended to be sicker — 62 percent
The results come from real-world cent, who took a placebo worsened, and entered the study with COVID-19 symp-
use of the drug to treat workers at the four needed hospitalization, researchers toms compared with 42 percent of the
Golden Gate Fields horse racing track reported in November in JAMA. group that declined treatment. No one
in Berkeley, Calif. Of those who opted to It wasn’t just the trial results that who took the drug suffered serious
take fluvoxamine, none got sicker, and intrigued Seftel, however. “I immediately complications, and after 14 days, none
within two weeks, symptoms cleared. In dove into the biochemistry,” he says. reported lingering symptoms. But six
comparison, 12.5 percent of those who The drug ’s biochemistry implied of 48 people who declined fluvoxamine
turned down the drug wound up hos- it might be able to regulate cellular were hospitalized, and one died. What’s
pitalized. Two people got responses to stress and more, 60 percent still reported experi-
0
so sick they were put on infection. Fluvoxamine is a encing a variety of symptoms including
ventilators to assist with selective serotonin reuptake shortness of breath and muscle and joint
breathing, and one of them inhibitor, or SSRI, typically pain two weeks after their diagnosis.
died, researchers report percent prescribed for obsessive- Even though it wasn’t a randomized,
online February 1 in Open Proportion of COVID-19 compulsive disorder. SSRIs controlled trial, the racetrack study adds
Forum Infectious Diseases. patients in a new study prolong signaling of the to evidence that there may be a benefit
The data need verifica- who took fluvoxamine chemical messenger sero- to giving fluvoxamine to patients with
and were hospitalized
tion from ongoing larger tonin in the brain. The COVID-19. “It wasn’t blinded. Overt
12.5
clinical trials. Still, some drugs, most notably flu- and unconscious bias can occur when
experts say that the new voxamine, also activate a you know who’s getting treatment or
findings, along with cell, protein called sigma-1 not,” says Jeffrey Klausner, an infectious
animal and human obser- receptor that prevents disease physician at the University of
percent
vational data, suggest production of chemical Southern California in Los Angeles who
Proportion of patients
that a two-week course of who did not take the drug messengers that exacerbate was not involved with the research. But
fluvoxamine, which costs and were hospitalized inflammatory reactions. “it definitely reduces the likelihood that
about $10 and is already In a 2019 study, mice the [JAMA] study was just by chance.”
approved by the U.S. Food and Drug that lacked sigma-1 receptor died Researchers at Washington University
Administration, could be considered for from systemic inflammation known as School of Medicine in St. Louis are test-
patients at high risk of suffering severe sepsis; fluvoxamine treatment protected ing fluvoxamine in a larger, randomized
COVID-19 symptoms. animals from deterioration and death. nationwide trial financed by Kirsch’s
Racetrack physician David Seftel and Lab dish experiments described in the fund and other philanthropic sources.
David Boulware, an infectious disease Dec. 4 Science showed that knocking Participants get pills, either fluvoxamine
physician-scientist at the University of down levels of sigma-1 receptor in cul- or placebo, shipped to their homes, along
Minnesota Medical School in Minneapo- tured cells lowered infection rates with with a thermometer, pulse oximeter
lis, led the real-world test after hundreds SARS-CoV-2, the virus that causes and blood pressure monitor. Partici-
of track workers became infected with the COVID -19. Fluvoxamine also blocks pants take the pills for 15 days and log
coronavirus in November. That month, activation of platelets, blood components symptoms on a web-based platform.
Seftel had heard about fluvoxamine dur- important for clotting. This anti-platelet As of February 4, the trial had enrolled
ing a presentation by tech entrepreneur activity, together with the mouse and cell 200 people, says coinvestigator Angela
Steve Kirsch, whose COVID-19 Early data, explain how fluvoxamine might Reiersen, a child psychiatrist. The team
Treatment Fund supports research squelch out-of-control immune activ- hopes to collect data from 880 people.
on existing drugs that could be repur- ity and prevent blood clots — both key Randomized trials in Korea, Brazil and
posed to treat coronavirus infections features of severe COVID-19. Hungary are also investigating fluvox-
(SN: 9/26/20, p. 8). Seftel shared the emerging data on amine as a possible treatment in patients
Kirsch shared results from a fund- fluvoxamine with 113 infected racetrack with mild to moderate COVID-19. s
www.sciencenews.org | February 27, 2021 7
fluvoxamine.indd 7 2/10/21 9:52 AM
NEWS
LIFE & EVOLUTION
Naked mole-rats
squeak in dialects
Unique ‘chirps’ may help group
Like modern
bobbit worms,
members recognize each other
ancient worms
may have dug BY JONATHAN LAMBERT
holes in the When one naked mole-rat encoun-
seafloor to lie
in wait before ters another, their chirps might reveal
attacking prey whether they’re friends or foes.
(illustrated). These rodents are famous for their
wrinkly, hairless appearance. But hang
LIFE & EVOLUTION also points to the worm emerging from around one of their colonies for a while,
Fossil lairs hint at its hideout, retreating and then rebuild-
ing the top sections over and over again.
and you’ll notice something else — naked
mole-rats are a chatty bunch. Their bur-
ambush attacks “These [funnels] suggest that the
worm repeatedly dragged its prey down
rows resound with near-constant chirps,
grunts, squeaks and squeals.
Ancient worms may have hid into the sediment,” says study coauthor A computer algorithm has uncovered
in the seafloor before striking Ludvig Löwemark, a geoscientist at a hidden order within this cacophony,
National Taiwan University in Taipei. researchers report in the Jan. 29 Science.
BY HELEN THOMPSON These hunting tactics are consistent Distinctive chirps that pups learn help
About 20 million years ago, giant ocean with those of bobbit worms, which con- the mostly blind, xenophobic rodents
worms may have burrowed into the sea- ceal their 3-meter-long bodies in sand discern who belongs, strengthening the
floor and burst forth like the space slug in and surge forth to grab unsuspecting bonds that maintain cohesion in these
Star Wars to ambush unsuspecting prey. fish with scissorlike jaws. While the highly cooperative groups.
Underground lairs left behind by these oldest evidence of bobbit worms dates “Language is really important for
animals appear in rocks from coastal to around 400 million years ago, how extreme social behavior, in humans, dol-
Taiwan, researchers report January 21 in or if the burrow diggers relate to bobbit phins, elephants or birds,” says Thomas
Scientific Reports. The diggers may have worms is unknown. Park, a biologist at the University of
been analogs of today’s bobbit worms Because the animals that lived in these Illinois at Chicago who wasn’t involved
(Eunice aphroditois), which bury them- ancient tunnels were invertebrates, they in the study. This work shows naked
selves in sand to surprise and strike fish. didn’t have skeletons to leave behind in mole-rats (Heterocephalus glaber)
Paleontologist Masakazu Nara of the fossil record. “It is almost always a belong in those ranks as well, Park says.
Kochi University in Japan first spot- challenge to link fossil traces to spe- Naked mole-rat groups resemble ant
ted the fossilized burrows in 2013. cific trace makers,” says David Rudkin, or termite colonies. Every colony has
Eventually, Nara and colleagues found an invertebrate paleontologist at the one breeding queen who suppresses
319 specimens. The team determined the Royal Ontario Museum in Toronto, who the reproduction of tens to hundreds of
burrows were up to 2 meters long and was not involved with this study. Still, workers that dig elaborate subterranean
2 to 3 centimeters wide. To make these Rudkin thinks that the case for ancient tunnels in search of tubers in eastern
tunnels, the animals drilled L-shaped bobbit worms hiding in these burrows Africa. Food is scarce, and the rodents
paths into the seafloor. The paths had a is convincing. attack intruders from other colonies.
funnel structure at the top that looks like If ancient bobbit worms did terrorize While researchers have long noted
a feather in vertical cross sections. the seafloor back then, the burrows are the raucous chatter, few have studied it.
FELIX PETERMANN/MAX DELBRÜCK CENTER
Some kind of giant worm likely dug a rare example of invertebrates hunting “Naked mole-rats are incredibly coopera-
Y-Y. PAN ET AL/SCIENTIFIC REPORTS 2021
the burrows, the researchers conclude, vertebrates — usually it’s the other way tive and incredibly vocal, and no one has
because the burrows lack the hallmark around. Bobbit worms’ presence would really looked into how these two features
pellets lining shrimp tunnels and had also make the local ecosystem more com- influence one another,” says neuroscien-
smoother linings than bivalve tunnels. plex than previously thought, Löwemark tist Alison Barker of the Max Delbrück
Iron deposits along the inside suggest says. “There was obviously a whole lot Center for Molecular Medicine in Berlin.
the digger must have been long and more going on at the seafloor 20 million She and colleagues used machine
slender and used mucus to reinforce the years ago than one would imagine when learning to analyze over 30,000 “soft
walls. Funneling at the top of burrows seeing these sandstones,” he says. s chirps” — a common vocalization — from
8 SCIENCE NEWS | February 27, 2021 Watch a bobbit worm’s sneak attack at bit.ly/SN_BobbitWorm
thumb_mole_worm.indd 8 2/10/21 10:38 AMseven lab colonies over two years. Each to new colonies. If dialect stems from London. Still, he says the results strongly
colony had a unique sound, varying pri- genetics, these outsiders should still suggest that dialects of naked mole-rats
marily in frequency and how much that sound like outsiders as they grow up. are learned, similar to those of humans,
frequency changes within a single chirp. But if dialects are learned, transplanted cetaceans and some birds.
Naked mole-rats pick up on these dif- pups should sound like their new breth- While a colony’s sound is distinctive,
ferences too, replying to the sounds of ren. The latter was true. it’s not fixed. In periods of anarchy —
r their own colony with frequent chirping “A sample size of three is small, but when a queen dies and is not yet
but largely ignoring foreign dialects, the these are really difficult experiments to replaced — dialects start to dissolve,
researchers found. The animals aren’t do,” says Chris Faulkes, an evolutionary becoming much more variable, the
- just responding to voices they’ve heard ecologist at Queen Mary University of researchers found. Once a new queen
al before either, as artificially concocted emerges, the colony coheres again, sug-
calls matched to a specific dialect also gesting that in addition to suppressing
r elicited a response. reproduction, queens also somehow
g A bit of luck allowed Barker’s team control a colony’s voice.
e, to test whether dialects are learned “We tend to think of this communica-
d or genetically encoded. Most colonies tion and cooperation as positive aspects
- reject outsiders, but sometimes pups of naked mole-rat culture, but individu-
s, from other groups can get adopted. als are rigidly controlled in their behavior
Multiple lab populations produced new by the queen,” Barker says. “It gives
Naked mole-rats from different colonies have
d litters around the same time, allowing distinctive dialects, which help maintain colony them a huge survival advantage, but it’s a
y, the team to switch three youngsters cohesion, a new study suggests. bit like living in an oppressive regime.” s
e.
p
s HUMANS & SOCIETY be able to perform most [tool-related]
e
e Humanlike grips go back 2 million years hand movements, but not as efficiently
as humans or other Homo species we
Thumb dexterity gave some hominids an edge in toolmaking studied,” Harvati says. The tool-wielding
r repertoire of Australopithecus fell closer
- BY BRUCE BOWER humans and five chimpanzees. Surpris- to that of modern chimpanzees, which
s Thumb dexterity similar to that of ingly, Harvati says, a pair of roughly use twigs to collect termites and wield
f people today already existed around 2-million-year-old thumb fossils from rocks to crack nuts, she suggests.
d 2 million years ago, possibly in some of South Africa display agility and power on The new study goes beyond past efforts
d the earliest members of our own genus par with modern human thumbs. that focused only on the size and shape
) Homo, a new study indicates. That find- Scientists disagree about whether the of ancient hominid hand bones. Using
s. ing is the earliest evidence to date of an South African finds come from early data from humans and chimpanzees on
t evolutionary transition to hands with Homo or Paranthropus robustus, a spe- how hand muscles and bones interact
s powerful grips comparable to those of cies on a dead-end branch of hominid while moving, the team constructed a
s human toolmakers, who didn’t appear evolution. But the thumb dexterity in digital 3-D model to re-create how a key
f for roughly another 1.7 million years. those ancient fossils is comparable to thumb muscle — musculus opponens
n Thumbs that enabled a forceful grip that found in members of Homo spe- pollicis — attached to a bone at the base
n and improved the ability to manipulate cies that appeared after around 335,000 of the thumb and operated to bend the
s objects gave ancient Homo or a closely years ago, the researchers report online digit’s joint toward the palm and fingers.
related hominid line an advantage over January 28 in Current Biology. That The new findings on how ancient
d hominid contemporaries, says a team includes Neandertals from Europe thumbs worked underscore the slow-
t. led by Fotios Alexandros Karakostis and and the Middle East, as well as a South ness of hominid hand evolution, says
FELIX PETERMANN/MAX DELBRÜCK CENTER
- Katerina Harvati. Australopithecus made African hominid dubbed Homo naledi. paleoanthropologist Matthew Tocheri
Y-Y. PAN ET AL/SCIENTIFIC REPORTS 2021
s and used stone tools but lacked human- By comparison, the researchers con- of Lakehead University in Thunder Bay,
s like thumb dexterity, thus limiting its clude, Homo or P. robustus possessed Canada. Australopithecus made stone
- toolmaking capacity, the paleoanthro- thumbs that were more forceful than tools as early as about 3.4 million years
k pologists, both from the University of those of three several-million-year-old ago (SN: 6/13/15, p. 6). “But we don’t see
n. Tübingen in Germany, found. Australopithecus species, two of which major changes to the thumb until around
e The team digitally simulated how a key have previously been proposed to have 2 million years ago,” he says, “soon after
t muscle influenced thumb movement in had humanlike hands (SN: 2/21/15, p. 9). which stone artifacts become far more
m 12 fossil hominids, five 19th century “Australopithecus would probably common across the African landscape.” s
m Listen to naked mole-rat dialects at bit.ly/SN_NakedMole-Rats www.sciencenews.org | February 27, 2021 9
thumb_mole_worm.indd 9 2/10/21 10:38 AMNEWS
sequenced the tuatara’s mitochondrial
genome in one fell swoop, showing its
overall structure. The technique, called
long-read sequencing, “is undoubtedly
the future of gene sequencing, that we
can sequence whole molecules in one
pop,” Macey says.
Dan Mulcahy, a molecular biologist
at the Smithsonian’s Global Genome
Initiative in Washington, D.C., and
Macey were mulling over the data when
Mulcahy recalls saying, “I think there
Having two distinct may be two [mitochondrial] genomes!”
mitochondrial genomes may
help explain how the tuatara, The revelation came from compar-
a reptile native to New ing both the chopped puzzle pieces and
Zealand, tolerates the cold. the overall structure, and noticing that
sections from the same part of the mito-
GENES & CELLS chondrial DNA had striking differences
The tuatara hides an extra set of genes in their gene sequences — like the way
the notes of a song might be arranged
It’s the only known vertebrate with two mitochondrial genomes differently by two different compos-
ers. The variation raised eyebrows;
BY DEVIN A. REESE of other animals could offer clues to the mitochondrial DNA is usually inherited
New Zealand’s lizardlike tuatara already inner workings of human disease, the only from a mother’s egg, so the scien-
was an oddball. Its superpowers include researchers say. tists expected to see a single copy of the
a nearly century-long life span, resistance “The mitochondrial genome is much mitochondrial genome, not two copies
to many diseases and a high tolerance (for more important than people realize, like they would see with nuclear DNA,
a reptile) to the cold. Now, it turns out, given its association with aging and dis- which is inherited from both the mother
a part of the tuatara’s genetic instruc- ease,” says Robert Macey, a genomicist and father.
tion book is as weird as the animal’s life at the Peralta Genomics Institute in Together, the scientists painstak-
history — and may help explain the tua- Oakland, Calif. “How that operates in an ingly assembled two fully functional
tara’s ability to be active at temperatures animal that ages slowly in a cool environ- mitochondrial genomes. The genomes
as low as about 6° Celsius. ment might tell us something significant differed by 10.4 percent. In comparison,
Tuatara have two distinct copies of about how mitochondria work.” human and chimpanzee mitochondrial
the genetic instruction manual for mak- Efforts to decode the tuatara’s genetic genomes differ by 8.9 percent. “The tua-
ing mitochondria, researchers report makeup began in 2012, with the launch tara’s arrangement of genes is unlike any
January 29 in Communications Biology. of the Tuatara Genome Project led by other vertebrate,” Mulcahy says.
“It’s the first evidence of a full addi- Neil Gemmell, an evolutionary biologist When Lara Urban, a genomicist at
tional copy of the mitochondrial genome at the University of Otago in Dunedin, the University of Otago, analyzed the
in a vertebrate,” says Chris Schneider, a New Zealand. After getting the blessing two genomes, she noticed differences
herpetologist at Boston University who of the Maori people to sample the rep- between genes related to metabolism.
was not involved in the study. Some mol- tile’s blood (tuatara are a taonga, special Cell metabolism adjusts to help an ani-
lusks are the only other animals ever treasure, to the Maori), the team found mal cope with environmental extremes.
found to have two copies. the genome to be 50 percent larger than The double mitochondrial genome
Mitochondria are tiny energy fac- the human genome. might give the tuatara flexibility in how
tories found in cells, and their genetic This discovery led to deeper explo- its metabolism responds to the cold, the
material is important in building the ration of the mitochondrial part of the scientists say.
enzymes that keep the mitochondria genome. Most techniques that deci- “The tuatara has the most complicated
BERNARD SPRAGG. NZ/FLICKR
running. Recent studies show that pher, or sequence, DNA chop it into mitochondrial genome I’ve ever seen,”
mitochondrial DNA plays major roles small pieces, “read” the DNA and then Macey says. Finding the genetic basis for
in aging and various human cancers, as reassemble the pieces. That provides a the animal’s metabolic feats could clarify
well as metabolic, muscular and neuro- high-resolution look at individual puz- the mitochondrial genome’s function,
degenerative diseases (SN: 11/17/12, p. 5). zle pieces. Piloting a new technique that helping to find treatments for human
Studying the mitochondrial genomes reads long DNA segments, Macey’s lab metabolic diseases. s
10 SCIENCE NEWS | February 27, 2021
tuatara.indd 10 2/10/21 9:53 AMEARTH & ENVIRONMENT of material far below the seafloor.
Upwellings may push continents apart In those signals, Agius’ team saw hints
of material from Earth’s lower mantle,
Mid-ocean ridges may play an unexpected role in plate tectonics more than 600 kilometers below the
seafloor, welling up toward the Mid-
BY MARIA TEMMING sliding apart. Rather, deep rock push- Atlantic Ridge. “This was completely
An upsurge of hot rock from deep ing toward the surface may be driving a unexpected,” Agius says, and it could be
beneath the Atlantic Ocean may be driv- wedge between the plates, researchers a powerful force for pushing apart the
ing the continents on either side apart. report in the Jan. 28 Nature. tectonic plates on either side of the rift.
The Americas are moving away from A better understanding of plate tec- “It’s certainly an interesting observa-
Europe and Africa by a few centimeters tonics, which causes earthquakes and tion,” says Jeroen Ritsema, a seismologist
each year, as the tectonic plates underly- volcanic eruptions, could help people bet- at the University of Michigan in Ann
ing those continents drift apart. Scientists ter prepare for these natural disasters. Arbor. But it’s hard to tell how much deep
typically think tectonic plates separate Matthew Agius, a seismologist at Roma mantle upwelling contributes to Atlantic
as the distant edges of those plates sink Tre University in Rome, and colleagues seafloor spreading based on observations
down into Earth’s mantle, creating a gap glimpsed what’s happening beneath the from only one group of seismometers
(SN: 1/16/21, p. 16). Material from the Mid-Atlantic Ridge using 39 seismome- near the equator, he says. It’s like “you’re
upper mantle seeps up through the rift ters on the seafloor near a spot along the looking through a keyhole, and you’re try-
between the plates to fill in the seafloor. ridge between South America and Africa. ing to see what’s in the living room and
But new seismic data show that hot Those sensors monitored rumbles from the bedroom and the kitchen.”
rock is welling up beneath a seafloor quakes around the world for about a year. Observations at other locations along
rift called the Mid-Atlantic Ridge from Because the seismic waves from those the Mid-Atlantic Ridge, as well as at other
hundreds of kilometers deep in Earth’s quakes traveled deep through Earth’s mid-ocean ridges, could help determine
mantle. This suggests that material mantle on their way to the seismom- whether deep mantle material surging up
rising up under the ridge is not just eters, the recorded tremors contained beneath these rifts really plays a major
a passive response to tectonic plates clues about the location and movement role in seafloor spreading. s
www.sciencenews.org | February 27, 2021 11
11_atlantic-ridge.indd 11 2/10/21 9:56 AMNEWS
ATOM & COSMOS identified any natural cosmic accelera- e
Milky Way’s glow is highly energetic tors capable of reaching a PeV, dubbed
PeVatrons. One possibility is that super-
h
h
New find points to the existence of powerful cosmic accelerators nova remnants, the remains of exploded a
stars, host shock waves that can acceler- U
BY EMILY CONOVER mysterious, highly energetic cosmic rays, ate cosmic rays to such energies. r
The Milky Way glows with a gamma ray charged particles that careen through the If PeVatrons exist, the cosmic rays t
haze, with energies vastly exceeding any- galaxy, sometimes crashing into Earth’s they emit would permeate the galaxy, g
thing physicists can produce on Earth, atmosphere. When cosmic rays, which producing a diffuse glow of gamma rays
according to a new paper. Gamma rays mainly consist of protons, slam into inter- of extreme energies. That’s just what e
reported in the study, to be published stellar debris, they can produce gamma researchers with the Tibet AS-gamma r
in Physical Review Letters, came from rays, a form of high-energy light. experiment found. “It’s nice to see things 1
throughout the galaxy’s disk, and reached Certain galactic environments could fitting together,” says physicist David c
nearly a quadrillion (1015) electron volts, rev up cosmic ray particles to more than Hanna of McGill University in Montreal, b
known as a petaelectron volt or PeV. a PeV, scientists suspect. In comparison, who was not involved with the study. f
These diffuse gamma rays hint at the the Large Hadron Collider, the premier After cosmic rays are spewed from e
existence of powerful cosmic particle particle accelerator crafted by humans, their birthplaces, scientists believe e
accelerators in the Milky Way. Physicists accelerates protons to 6.5 trillion electron they roam the galaxy, twisted about by t
believe such accelerators are a source of volts. But physicists haven’t definitively its magnetic fields. “We live in a bub- c
ble of cosmic rays,” says astrophysicist g
The Tibet AS-gamma experiment (shown) in China detects high-energy gamma rays by Paolo Lipari of the National Institute c
observing showers of particles produced when a gamma ray hits Earth’s atmosphere. for Nuclear Physics in Rome, who was
not involved with the research. Because t
they are not deflected by magnetic fields,
gamma rays point back to their sources, e
revealing the whereabouts of the itiner- i
ant cosmic rays. The new study “gives W
you information about how these par- n
ticles fill the galaxy,” Lipari says. g
Lower-energy gamma rays also perme- d
ate the galaxy. But it takes higher-energy g
gamma rays to understand the highest- c
ATOM & COSMOS sands of planets orbiting other stars. Thompson’s group ground samples c
Meteorites hint at Like the terrestrial planets in the solar
system, many could have rocky surfaces
of the meteorites to powder, and then
heated the powder in a furnace hooked
a
g
early atmospheres beneath thin atmospheres. Some space
telescopes can peek at starlight filtering
up to a mass spectrometer to measure
trace amounts of different gases that
c
Water-rich steam may envelop through exoplanet atmospheres to figure escaped as the powder warmed. m
INSTITUTE OF HIGH ENERGY PHYSICS OF THE CHINESE ACADEMY OF
young rocky exoplanets out what chemicals they contain, and if That setup is analogous to how rocky a
the worlds could be hospitable to life. planets form their initial atmospheres e
BY LISA GROSSMAN Instead of looking at the atmospheres after solidifying. A young planet heats r
By burning bits of meteorites, scientists themselves, Thompson and colleagues its rock with the decay of radioactive ele- c
may learn what the atmospheres of some are working from the ground up, exam- ments, collisions with asteroids or other c
young exoplanets are made of. ining rocky planets’ building blocks to see planets, and with the leftover heat from w
SCIENCES/XINHUA/ALAMY STOCK PHOTO
Experiments baking pulverized space what kind of atmospheres are possible. planetary formation. The warmed rock g
rocks suggest that rocky planets initially The team studied three carbonaceous lets off gas. “Measuring the outgassing
have atmospheres full of water, Maggie chondrite meteorites. These rocks repre- composition from meteorites can provide f
Thompson, an astrophysicist at the Uni- sent the first solids that condensed out of a range of atmospheric compositions for c
EMANUELE OLIVETTI
versity of California, Santa Cruz, reported the disk of dust and gas that surrounded rocky exoplanets,” Thompson said. t
January 15 at the virtual meeting of the the young sun and ultimately formed the All three meteorites mostly let off t
American Astronomical Society. planets in the solar system. Exoplanets water vapor, accounting for 62 percent of K
Astronomers have discovered thou- probably formed from similar stuff. the gas emitted on average. The next most U
12 SCIENCE NEWS | February 27, 2021
milkyway-spider-multiplanet.indd 12 2/10/21 1:49 PMYou can also read
