EPA Warns Plutonians!
Pluto may be undergoing global warming
August 23, 2002 Posted: 11:15 AM EDT (1515 GMT)
By Richard Stenger
CNN
(CNN) -- Pluto could be experiencing a
warming trend on the surface and a
cooling trend in the atmosphere,
according to planetary scientists.
Astronomers made the deduction based on
observations of a recent stellar eclipse
when Pluto passed in front of the light of
star P126A.
When the planet eclipsed another star in
1998, the starlight went out quickly.
During the July event, the light dimmed
slowly as Pluto passed in front.
By studying the starlight, scientists
estimated the density, pressure and
temperature of Pluto's atmosphere.
"In the last 14 years, one or more changes have occurred," said Marc Buie of
Lowell Observatory in Flagstaff, Arizona. "Pluto's atmosphere is undergoing global
cooling, while other data indicates that the surface seems to be getting slightly
warmer.
"Change is inevitable as Pluto moves away from the sun, but what we're seeing is
more complex than ex pected," said Buie, who with James Elliot of the
Massachusetts Institute of Technology reported the findings last week.
Pluto has a highly eccentric orbit and is heading away from the sun to the most
distant point in its travels.
Astronomers theorize that during such times Pluto's atmosphere freezes over for
more than a century.
The scientists will be able to get more data when Pluto passes in front of another
star Tuesday.
Such star eclipses or occultations are taking place more frequently because Pluto is
moving in line with the main band of the Milky Way, where stars are more
commonplace.
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