Science - USA (2022-02-25)

SCIENCE science.org

PHOTOS: (TOP TO BOTTOM KENT SUNDELL/CASPER COLLEGE; YASEMIN OZKANAYDIN/UNIVERSITY OF NOTRE DAME

was plentiful.) They report on 23 February

in Nature that the fish—along with three-

quarters of life on Earth—perished during

spring in the Northern Hemisphere.

Centipedes inspire robot

BIOLOGY | Centipedes’ ability to speed

over rock, sand, and soil has led to a new

robot that could prove handy to farmers.

On land, centipedes move their legs in a

wave that switches direction when they

encounter obstacles, researchers reported

this month at the virtual meeting of the

Society of Integrative and Comparative

Biology. In water, they wiggle their bodies

to move forward. To better understand how

the animals coordinate their legs and body

in different environments, the research-

ers built a 70-centimeter robot model and

determined the most efficient timing of leg

and body movements. The robot was so

adept at moving across a natural landscape

that the team has formed a company to

develop the device for finding and destroy-

ing weeds in agricultural fields.

Psilocybin shows lasting effects

MENTAL HEALTH | The antidepressant

effects of psilocybin-assisted therapy

may last at least 1 year for some people,

a small follow-up study suggests. In a

clinical trial of 24 people with major

depressive disorder, researchers found

that two doses of the substance found in

magic mushrooms, given approximately

2 weeks apart alongside psychotherapy,

led to clinically significant reductions in

depression severity in 18 participants and

remission in 14 of them after 1 year. The

results, reported last week in the Journal

of Psychopharmacology and discussed in

A robot mimics the leg and body movements of centipedes to move efficiently over uneven terrain. a panel at the annual meeting of AAAS,

GEOLOGY

First secondary craters found on Earth point to giant asteroid impact

An elliptical secondary

crater on Sheep

Mountain in Wyoming.

S

cientists have identified a series of 31 craters in Wyoming

with diameters from 10 to 70 meters, created 280 million

years ago by boulders ejected from a previously unknown

cosmic impact. Such “secondary” craters are common

on airless moons and planets, but previously have never been

identified on Earth. Many scientists suspected the planet’s

thick atmosphere would prevent their formation altogether

by cracking up boulders on descent. The finding, published this

month in the Geological Society of America Bulletin, also sug-

gests a 60-kilometer-wide impact crater is likely buried some

2 kilometers below Wyoming’s eastern border—potentially one

of the largest known impacts in North American history.

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