Science - USA (2022-01-14)

NEWS | IN BRIEF

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PHOTO: NASA/BILL INGALLS/CC BY

are cheaper to build and theoretically safer.
At the Shidao Bay Nuclear Power Plant in
eastern China, designers opted for a “pebble
bed” design, in which nuclear fuel is encased
in spherical graphite “pebbles” the size of
tennis balls that are packed into a cylindri-
cal vessel like gumballs in a jar. Circulating
helium is heated by the pebbles to 750°C,
and the hot gas produces steam. An identical
pair of these reactors will jointly generate
210 megawatts of electricity. Developers are
now planning to link six reactor modules
together in a 650-megawatt plant. U.S.
regulators have yet to approve a leading
small-reactor design from the company
NuScale Power because of concerns over the
reliability of its passive safety features.

Ocean warming sets record

CLIMATE | The upper reaches of the

world’s oceans were hotter than ever in

2021, setting a record for the sixth straight

year. The shallowest 2000 meters of the

oceans last year absorbed 14 more zetta-

joules (10^21 joules) of heat than in 2020,

an injection of energy equivalent to nearly

30 times as much energy as humans use in

a single year, scientists reported this week

in Advances in Atmospheric Sciences. The

ocean acts as a buffer against rising tem-

peratures, absorbing an estimated 90% of

the extra heat trapped by global warming.

Surface air temperatures, more mercu-

rial than the ocean, didn’t set a record

in 2021—it was merely the fifth warm-

est year, and between 1.1°C and 1.2°C

above the late 19th century’s average, the

European Union’s Copernicus Climate

Change Service announced this week.

Despite economic slowdowns triggered

by the pandemic, two key greenhouse

gases rose to record levels in the atmo-

sphere, with carbon dioxide at 414 parts

per million and methane at 1876 parts

per billion, according to the service.

NASA names chief scientist

CLIMATE POLICY | Katherine Calvin, a

researcher who studies the impacts of

global warming, was appointed this week

to be NASA’s new chief scientist and

senior climate adviser. Calvin has worked

since 2008 at the Pacific Northwest

National Laboratory, modeling how

climate change will alter farming, water

use, and other aspects of human society.

Calvin will advise Bill Nelson, NASA’s

administrator, as the agency grapples

with adapting to climate change, includ-

ing planning the long-term future of the

Kennedy Space Center in Florida and

other prominent space facilities on coast-

lines vulnerable to sea level rise. (The

chief scientist position does not directly

oversee NASA’s scientific missions, includ-

ing those focused on climate; those are

managed by Associate Administrator

Thomas Zurbuchen.)

Pill curbs but doesn’t erase yaws

INFECTIOUS DISEASES | Eradicating

yaws—a painful and disfiguring bacterial

disease—may be harder than scientists

hoped, a study published last week in

The New England Journal of Medicine

suggests. The World Health Organization

aims to eradicate yaws by 2030; its

strategy calls for mass treatment of

communities using a single dose of the

inexpensive oral antibiotic azithromycin,

followed by targeted treatment for peo-

ple who develop the disease’s hallmark

skin ulcers and their contacts. In the

trial, involving 56,000 people in Papua

New Guinea, that regimen reduced yaws

prevalence by 65%. An alternative, inten-

sified treatment—three communitywide

doses of azithromycin given 6 months

apart—did markedly better, lowering

prevalence by 91%. But it didn’t wipe out

the disease, as the scientists had hoped,

and a few cases of antibiotic resistance

resulted, raising concern.

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ASTROPHYSICS

Webb telescope fully formed

T

he James Webb Space Telescope, the largest space observatory ever launched,

completed most of its delicate in-space deployments last week after unfolding two

wings of its 6.5-meter main mirror. Webb has now executed 85% of several hun-

dred mechanical actions that could jeopardize the mission were any to fail. Next,

operators will fine-tune the positions of the main mirror’s 18 gold-plated segments

with 126 tiny motors to form a single reflecting surface; then, the team will calibrate

Webb’s four instruments, which must be cooled below –230°C to see in the infrared.

Expected this summer is a first image, one that will demonstrate Webb’s unprecedented

capability to peer into the early universe and other worlds—then the science begins.

Engineers monitor James Webb

Space Telescope operations.

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