These red, orange and green clouds (false color) in Saturn's northern
hemisphere indicate the tail end of the massive 2010-2011 storm. Even
after visible signs of the storm started to fade, infrared measurements
continued to reveal powerful effects at work in Saturn's stratosphere.
(Credit: NASA/JPL-Caltech/Space Science Institute)
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› Larger image (TIF)
NASA Spacecraft Sees Huge Burp at Saturn After Large Storm
10.25.12
Data from Cassini's composite infrared spectrometer (CIRS) instrument revealed the storm's powerful discharge sent the temperature in Saturn's stratosphere soaring 150 degrees Fahrenheit (83 kelvins) above normal. At the same time, researchers atin Greenbelt, Md., detected a huge increase in the amount of ethylene gas, the origin of which is a mystery. Ethylene, an odorless, colorless gas, isn't typically observed on Saturn. On Earth, it is created by natural and man-made sources.
Goddard scientists describe the unprecedented belch of energy in a paper to be published in the Nov. 20 issue of the Astrophysical Journal.
The 150 F jump in Saturn's stratosphere during the 2010 Great White Spot
storm has set a new record for the largest atmospheric temperature
change ever detected during a storm on the ringed planet.
(Credit: NASA's Goddard Space Flight Center)
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"This temperature spike is so extreme it's almost unbelievable,
especially in this part of Saturn's atmosphere, which typically is very
stable," said Brigette Hesman, the study's lead author and a University
of Maryland scientist who works at Goddard. "To get a temperature change
of the same scale on Earth, you'd be going from the depths of winter in
Fairbanks, Alaska, to the height of summer in the Mojave Desert."
First detected by Cassini in Saturn's northern hemisphere on Dec. 5,
2010, the storm grew so large that an equivalent storm on Earth would
blanket most of North America from north to south and wrap around our
planet many times. This type of giant disturbance on Saturn typically
occurs every 30 Earth years, or once every Saturn year.
Not only was this the first storm of its kind to be studied by a
spacecraft in orbit around the planet, but it was the first to be
observed at thermal infrared wavelengths. Infrared data from CIRS
allowed scientists to take the temperature of Saturn's atmosphere and to
track phenomena that are invisible to the naked eye.
Temperature
measurements by CIRS, first published in May 2011, revealed two unusual
beacons of warmer-than-normal air shining brightly in the stratosphere.
These indicated a massive release of energy into the atmosphere. After
the visible signs of the storm started to fade, CIRS data revealed the
two beacons had merged. The temperature of this combined air mass shot
up to more than minus 64 degrees Fahrenheit (above 220 kelvins).
According to Hesman, the huge spike of ethylene generated at the same
time peaked with 100 times more ethylene than scientists thought
possible for Saturn. Goddard scientists confirmed the release of the gas
using the Celeste spectrometer mounted on the McMath-Pierce Solar
Telescope on Kitt Peak in Arizona.
The forceful storm generated unprecedented spikes in temperature and
increased amounts of ethylene. In these two sets of measurements taken
by Cassini's composite infrared spectrometer, yellow represents the
highest temperatures. Each strip maps a single molecule (top: methane;
bottom: ethylene), with temperature measurements taken in the northern
hemisphere, all the way around the planet.
(Credit: NASA/JPL-Caltech/Goddard)
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The team still is exploring the origin of the ethylene, but has ruled out a large reservoir deep in the atmosphere.
"We've really never been able to see ethylene on Saturn before, so this
was a complete surprise," said Goddard's Michael Flasar, the CIRS team
lead.
A complementary paper led by Cassini team associate Leigh Fletcher of
Oxford University, England, describes how the two stratospheric beacons
merged to become the largest and hottest stratospheric vortex ever
detected in our solar system. Initially, it was larger than Jupiter's
Great Red Spot.
Their paper in the journal Icarus, which combines CIRS data with
additional infrared images from other Earth-based telescopes, including
NASA's Infrared Telescope Facility at Mauna Kea, Hawaii, also reports a
powerful collar of clockwise winds -- encompassing a bizarre soup of
gases -- around the vortex.
"These studies will give us new insight into some of the photochemical
processes at work in the stratospheres of Saturn, other giants in our
solar system, and beyond," said Scott Edgington, Cassini deputy project
scientist at NASA's Jet Propulsion Laboratory (JPL) in Pasadena, Calif.
The Cassini-Huygens mission is a cooperative project of NASA, the
European Space Agency, and the Italian Space Agency. The mission is
managed by JPL for NASA's Science Mission Directorate in Washington.
Hesman's work was funded in part by NASA's Planetary Astronomy Program
in Washington. The CIRS instrument and Celeste spectrometer were built
at Goddard.
Related Links
Text issued as NASA Headquarters release No. 12-375
Dwayne Brown
NASA Headquarters, Washington, D.C.
202-358-1726
dwayne.c.brown@nasa.gov
Elizabeth Zubritsky / Nancy Neal-Jones
NASA's Goddard Space Flight Center, Greenbelt, Md.
301-614-5438 / 301-286-0039
elizabeth.a.zubritsky@nasa.gov / nancy.n.jones@nasa.gov
Jia-Rui C. Cook
NASA's Jet Propulsion Laboratory, Pasadena, Calif.
818-354-0850
jccook@jpl.nasa.gov
Dwayne Brown
NASA Headquarters, Washington, D.C.
202-358-1726
dwayne.c.brown@nasa.gov
Elizabeth Zubritsky / Nancy Neal-Jones
NASA's Goddard Space Flight Center, Greenbelt, Md.
301-614-5438 / 301-286-0039
elizabeth.a.zubritsky@nasa.gov / nancy.n.jones@nasa.gov
Jia-Rui C. Cook
NASA's Jet Propulsion Laboratory, Pasadena, Calif.
818-354-0850
jccook@jpl.nasa.gov
NASA
Guillermo Gonzalo Sánchez Achutegui
ayabaca@gmail.com
ayabaca@hotmail.com
ayabaca@yahoo.com
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