STEVE the light show
Meet S TEVE, a nontraditional aurora
that drapes the sky with a mauve
ribbon and bedazzling green bling.
This feature of the northern
lights, first photographed and named
by citizen scientists in Canada, now
has a scientific explanation. The
streak of color, which appears to the
south of the main aurora, may be a
visible version of a typically invisible
process involving drifting charged
particles, or ions, physicist Elizabeth
MacDonald and colleagues report
March 14 in Science Advances.
Measurements from ground-based cameras and a satellite that
passed when STEVE was in full
swing show that the luminous band
is associated with a strong flow of
ions in the upper atmosphere,
MacDonald, of NASA’s Goddard
Space Flight Center in Greenbelt,
Md., and colleagues conclude. But
the researchers can’t yet say how the
glow arises from this flow.
Volunteers with a citizen science
project called Aurorasaurus (SN
Online: 4/3/15) gave the phenomenon
its moniker before STEVE’s association with ion drift was known.
MacDonald and colleagues kept the
The tattoo keepers
name, but gave the colorful display a
backronym: “Strong Thermal Emis-
sion Velocity Enhancement.”
We’ll stick with S TEVE.
Tattoos may have staying power because of handoffs between immune cells
known as macrophages, a group of French researchers says.
If true, this would overturn notions that the ink persists in connective tissue or in
long-lasting macrophages. Immunologist Sandrine Henri of the Immunology
Center of Marseille-Luminy and colleagues tattooed mice’s tails with green ink to
see how waste-disposing macrophages in the skin would respond.
“Macrophages will scavenge everything. That’s their job,” Henri says. “If they
could do their job properly, tattoo ink would be removed rapidly.” In the experi-
ment, described online March 6 in the Journal of Experimental Medicine,
macrophages gobbled up the ink but did not digest and remove it. Instead, the
cells held on to the ink until the researchers killed the
cells. About 90 days later, new macrophages moved in
and reabsorbed the ink, which had been floating in the
area. This capture-release-recapture cycle was key to
preserving the tattoos, the researchers say.
But a mouse study doesn’t settle the science of tattoos
in humans, says Desmond Tobin, a dermatology expert at
the University of Bradford in England. Macrophages may
live longer in people than in mice, and the persistence of
those cells might be responsible for preserving tattoos
in human skin, Tobin says. The findings may still help
improve tattoo removal, the authors say. Combining laser
therapy with a treatment to get rid of skin macrophages
could oust the ink. — Dan Garisto
Kids have evolving notions of ‘scientist’
Ask a classroom of children to draw a scientist, and you’ll see plenty of Crayola-colored lab coats, goggles and bubbling beakers. That image hasn’t changed much
since the 1960s. But the person wearing the lab coat is shifting, says David Miller, a
Ph.D. candidate in psychology at Northwestern University in Evanston, Ill.
From 1966 through 1977, the first of many “draw-a-scientist” studies asked
nearly 5,000 children to draw a scientist. “Of those 5,000 drawings, only
28 … depicted a female scientist,” Miller says. That’s 0.6 percent. To look for
changes in children’s perceptions over
time, Miller and colleagues combined data
from 78 more recent studies that included
a total of more than 20,000 U.S. children in
kindergarten through 12th grade.
On average, 28 percent of children drew
female scientists in studies conducted from
1985 to 2016, the researchers report online
March 20 in Child Development.
What hasn’t changed much: Kids pick
up gender stereotypes as they grow up.
At age 6, girls in the more recent studies
drew female scientists about 70 percent of
the time. By age 16, only 25 percent did so.
Tattoos on a mouse’s tail
appear the same before
(left) and after (right)
certain immune cells
were killed, because new
cells recaptured the ink.
A purplish and green band
of light is a newfound
light display appearing
in the sky during the
In a recent study, an 8-year-old Hispanic
girl from San Antonio drew a female scientist with a banner reading “best job ever.”