Some scorpions don't drink; Light hits the dark side of the Moon
Q: Do scorpions drink water? If they do, where do
they go to drink water? What do scorpions eat? Ryan, Fountain
Hills, Arizona
 A
Opistophthalmus scorpion crawling through the sands of the African
Namib Desert. Photo courtesy of Cesar Fernandez, copyright, used with
permission.
A: Depending on where they live, some scorpions drink water; others don't. These creatures,
closely akin to spiders and mites, are survivors. They evolved an
excellent body plan over 400 million years ago, and have seen little reason for
major change since. The 1500 living scorpion species have
adapted, though, to fill every conceivable habitat niche: from arid
African deserts to snow-covered Himalayan mountains over 12,000 feet (3660 m)
high.
Those that live in grasslands, forests, intertidal zones, rain forests,
mountain highlands and caves drink from streams and pools. In captivity, they will drink
regularly from wet wads of cotton wool left in their cage, the
International Wildlife Encyclopedia says.
The desert is a different matter. Some scorpions, living in deserts near the sea,
drink condensed fog.
On the morning of Aug. 13, 1989, a thick ocean fog rolled over the Namib Desert of southwest Africa.
Two biologists (Gary Polis from Vanderbilt University in Tennessee and
Mary Seely from the Desert Ecological Unit of Namibia)
spent forty minutes
watching a 3-inch
(8-cm) Parabuthus scorpion drink fog dew. The scorpion pushed her tan body slowly through the yellow grasses. She moved her small, sharp, claw-like mouthparts (chelicerae)
over the grass stems, obviously "collecting and drinking water."
Most desert species, however, don't drink water at all. Instead their
bodies separate water from the food they eat. In fact, scorpions can only
digest liquid food. Once they
get water, they keep it. Several layers of a waxy substance coat their exoskeleton, and trap the precious water.
Scorpions mainly eat insects and spiders, but will "prey upon anything they
can overpower within striking distance", including centipedes and other
scorpions,
Jonathan Leeming writes in Scorpions of Southern Africa. The larger
scorpions also occasionally eat small lizards, snakes and mice. Most
scorpions lurk outside their lairs at night, and ambush their prey.
Moreover, some scorpion species can wait out lean times, not eating at all for
more than a year.
Further Reading:
Scorpions glow in the dark, WonderQuest
Imbibition of precipitated fog by Gary A. Polis and Mary K. Seely, The
American Anarchnological Society
Scorpions, Jonathan
Leeming
Scorpions, University of Arizona
International Wildlife encyclopedia,
edited by Maurice Burton and Robert Burton
Q: Almost everyone that I talk to believes that the far side
of the moon is always dark (hence, the saying, "dark side of the moon").
Nobody believes me when I say the far side is completely lit by the sun, when
the moon is in New Moon phase, (that is to say dark). Can you help me
enlighten the folks out there? Kerry, Inyokern, California
A sunlit lunar crater, Daedalus, on the Moon's far side. Astronaut
Michael Collins took the picture, in July 1969, from the Apollo 11 spacecraft in
lunar orbit, as Neil Armstrong and Edwin Aldrin descended to the Moon's surface, and walked in sunlight. Courtesy of NASA.
A: The Moon rotates at the same speed as
it orbits the Earth. So, in the 27 days it takes the
Moon to go around Earth, the Moon also spins about its
axis one full revolution. That's why we always see the
same face of the Moon.
The side of the Moon we don't see is called the 'dark' side. However,
the word 'dark' is a matter of semantics. It's an early term meaning
'unknown' or 'unseen', like calling Africa the 'Dark' Continent. We, on Earth, never see the
'dark' side of the Moon from Earth, but suppose you
live on Moon, as some of us soon may. Then you will experience a day: the
Sun will rise and shine on the moonscape, move across the black lunar sky and — 27 days later — set
below the Moon's horizon. Click here to see
the Sun shine on the far (but not dark) side of the Moon. Then click
'animate' for a lively show. Courtesy of Chris Dolan and the University of
Wisconsin, Madison.
Further Reading:
Does the
Moon rotate? WonderQuest
Why does the Moon look so large on the horizon? WonderQuest
Moon phases, Keith's moon page
An animation showing how the Earth and the Moon orbit the Sun, Collins
A calendar
showing the moon phase for each day of the current month, StarDate Online
(Answered May 14, 2007)
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