Spaceflight Now Home



Spaceflight Now +



Subscribe to Spaceflight Now Plus for access to our extensive video collections!
How do I sign up?
Video archive

Discovery rolls out

Discovery travels from the Vehicle Assembly Building to pad 39A in preparation for the STS-124 mission.

 Play

STS-124: The programs

In advance of shuttle Discovery's STS-124 mission to the station, managers from both programs discuss the flight.

 Play

STS-124: The mission

A detailed preview of Discovery's mission to deliver Japan's science laboratory Kibo to the station is provided in this briefing.

 Part 1 | Part 2

STS-124: Spacewalks

Three spacewalks are planned during Discovery's STS-124 assembly mission to the station.

 Play

STS-124: The Crew

The Discovery astronauts, led by commander Mark Kelly, meet the press in the traditional pre-flight news conference.

 Play

Discovery to VAB

For its STS-124 mission, shuttle Discovery was transferred from its hangar to the Vehicle Assembly Building for attachment to a fuel tank and twin solid rocket boosters.

 Transfer | Hoist

Complex 40 toppling

The Complex 40 mobile service tower at Cape Canaveral's former Titan rocket launch pad was toppled using explosives on April 27.

 Play

Become a subscriber
More video



Saturn does the wave in upper atmosphere
NASA/JPL NEWS RELEASE
Posted: May 7, 2008

Two decades of scrutinizing Saturn are finally paying off, as scientists have discovered a wave pattern, or oscillation, in Saturn's atmosphere only visible from Earth every 15 years.


Credit: NASA/JPL
 
The discovery of the wave pattern is the result of a 22-year campaign observing Saturn from Earth (the longest study of temperature outside Earth ever recorded), and the Cassini spacecraft's observations of temperature changes in the giant planet's atmosphere over time.

The Cassini infrared results, which appear in the same issue of Nature as the data from the 22-year ground-based observing campaign, indicate that Saturn's wave pattern is similar to a pattern found in Earth's upper atmosphere. The earthly oscillation takes about two years. A similar pattern on Jupiter takes more than four Earth years. The new Saturn findings add a common link to the three planets.

Just as scientists have been studying climate changes in Earth's atmosphere for long periods of time, NASA scientists have been studying changes in Saturn's atmosphere. Glenn Orton of NASA's Jet Propulsion Laboratory in Pasadena, Calif., says patience is the key to studying changes over the course of a Saturnian year, the equivalent of about 30 Earth years.

"You could only make this discovery by observing Saturn over a long period of time," said Orton, lead author of the ground-based study. "It's like putting together 22 years worth of puzzle pieces, collected by a hugely rewarding collaboration of students and scientists from around the world on various telescopes."

The wave pattern is called an atmospheric oscillation. It ripples back and forth within Saturn's upper atmosphere. In this region, temperatures switch from one altitude to the next in a candy cane-like, striped, hot-cold pattern. These varying temperatures force the wind in the region to keep changing direction from east to west, jumping back and forth. As a result, the entire region oscillates like a wave.

A "snapshot" of the hot-cold temperature patterns in Saturn's atmosphere was captured by the Cassini Composite Infrared Spectrometer. Along with Earth-based data, the "snapshot" also uncovered other interesting phenomena. Among them: the temperature at Saturn's equator switches from hot to cold, and temperatures on either side of the equator switch from cold to hot every Saturn half-year.

Mike Flasar, co-author of the Cassini paper, and principal investigator for Cassini's Composite Infrared Spectrometer at NASA's Goddard Space Flight Center, Greenbelt, Md., said that Cassini helped define this oscillation in combination with the ground observation campaign.

"It's this great synergy of using ground-based data over time, and then getting up close and personal with the oscillation in Saturn's atmosphere through Cassini," said Flasar. "Without Cassini, we might never have seen the structure of the oscillation in detail."

Cassini scientists hope to find out why this phenomenon on Saturn changes with the seasons, and why the temperature switchover happens when the sun is directly over Saturn's equator.

The Cassini-Huygens mission is a cooperative project of NASA, the European Space Agency and the Italian Space Agency. JPL, a division of the California Institute of Technology in Pasadena, manages the Cassini mission for NASA's Science Mission Directorate, Washington, D.C. The Cassini orbiter was designed, developed and assembled at JPL. The Composite Infrared Spectrometer team is based at NASA's Goddard Space Flight Center, Greenbelt, Md.