Stem Cells a
FEBRUARY 2, 2019
SOCIETY FOR SCIENCE & THE PUBLIC
SCIENCE NEWS MAGAZINE
Research finds supplements don’t live up to the hype
VITAMIN D DISAPPOINTS
FEBRUARY 2, 2019
Initial observations of the Kuiper Belt
object MU69, nicknamed Ultima Thule,
suggested it had a snowmanlike shape.
Ultima Thule’s two lobes are connected
by a narrow neck that appears brighter
than the rest of the space rock’s surface,
Lisa Grossman reported in “New Horizons
swings by Ultima Thule” (SN: 2/2/19, p. 7).
“The photo of Ultima Thule was fas-
cinating,” reader Thomas Ostwald
wrote. “However, the explanation of the
bright ‘neck’ as grains that rolled ‘down-
hill’ was a shock! Which way is up?”
Scientists consider the “up” direc-
tion opposite the pull of gravity on
Ultima Thule. It helps to imagine
you’re standing on the space rock, says
James Tuttle Keane, a planetary
scientist at the California Institute of
If you were standing on the bigger
lobe (Ultima) and far away from the
smaller lobe (Thule), you’d primarily
feel the gravity of the big lobe and the
surface would seem flat, Keane says.
The pull of gravity would be perpendicular to the surface. The “up” direction
would also be perpendicular to the surface, pointing away from gravity’s pull.
As you move closer and closer to the
neck connecting the lobes, the gravitational pull from Thule would start
to have a bigger influence than before.
This would change the “up” direction.
It would no longer be perpendicular to
When “up” isn’t perpendicular,
there’s a slope. And so loose material
on the surface of MU69 might “slump
into” the neck region, Keane says.
But that is just one of the many ideas
scientists have for explaining Ultima
Thule’s bright neck.
Additional observations indicate
that the space rock is actually shaped
more like two lumpy pancakes stuck
together, rather than two snowballs
(see Page 15). That might change
scientists’ understanding of Ultima
Thule’s gravitational field “a little bit,”
Keane says. He and colleagues are
working on a study to figure out what
those changes could be.
Tweaking tobacco plants’ genetic
instructions boosted the efficiency of
photorespiration. The modified plants grew
roughly 40 percent bigger than plants that
had not been genetically altered, Maria
Temming reported in “Shortcut improves
photosynthesis” (SN: 2/2/19, p. 6).
Online reader Alice Friedemann
asked if engineered plants would
require more water than normal
Generally, larger plants require
more water than smaller plants, says
Paul South, a molecular biologist with
the U.S. Department of Agriculture in
Urbana, Ill. These engineered plants
“use the same amount of water per a
given area or size, but since they are
bigger they would use more water”
than nonengineered plants, he says.
Deflating vitamin D supplements
Vitamin D supplements may have fewer
health benefits than expected, Laura Beil
reported in “D is for discouraging”
(SN: 2/2/19, p. 16).
Reader Sandra Mack thought that
sunlight may deliver the health benefits
that researchers were expecting from
vitamin D supplements.
Both sunlight and supplements can
make up for deficiencies, Beil says.
But supplements are used in studies
because they safely deliver vitamin D
at higher levels. “Researchers still
haven’t determined whether sunlight
can safely deliver high amounts of
vitamin D,” she says.
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Astronomers spotted a mysterious
flare-up 200 million light-years
from Earth. Dubbed the “Cow,”
the flash may have resulted from
a star exploding in a new type
of supernova, Lisa Grossman
reported in “Cosmic ‘Cow’ baffles
scientists” (SN: 2/2/19, p. 13).
Sticking with the bovine theme,
Reddit user deadHD suggested
calling the event that created the
Cow a “moopernova.”