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Laboratory for Atmospheric and Space Physics

On October 15, 1997, the Cassini-Huygens spacecraft was launched by NASA’s Jet Propulsion Laboratory (JPL) from Kennedy Space Center in Florida. After a seven-year journey, it entered Saturn’s orbit on July 1, 2004 Coordinated Universal Time (UTC), or June 30 at 8:36 p.m. MDT. Cassini completed its initial four-year mission in June 2008 and the first extended mission, called the Cassini Equinox Mission, in September 2010. It is still collecting valuable data on its second extended mission, called the Cassini Solstice Mission.

The mission includes the Cassini orbiter, which orbit Saturn and its moons, and the Huygens probe, which was released from the Cassini orbiter and landed on the Titan moon to explore its surface and surroundings. The instruments onboard provide scientists with new and exciting data to help understand the mysterious Saturnian system.

The Ultraviolet Imaging Spectrograph (UVIS), is one of the 12 instruments installed on board Cassini. It was built by the Laboratory for Atmospheric and Space Physics (LASP) located in the Research Park of the University of Colorado in Boulder.

The instrument measures ultraviolet light in the Saturnian system. Data from UVIS provide information on the atmospheric composition and photochemistry of Saturn and Titan, and the nature and history of Saturn’s rings.

This site provides the public and the UVIS team members with a wealth of knowledge about the UVIS instrument as well as links to more information on the complete Cassini-Huygens mission.

Science Objectives

The Cassini Ultraviolet Imaging Spectrograph (UVIS) is part of the remote sensing payload of the Cassini Orbiter spacecraft.

UVIS science objectives include investigation of the:

  • Chemistry, clouds, and energy balance of the Titan and Saturn atmospheres
  • Neutrals in the magnetosphere
  • Surfaces and tenuous atmospheres of icy satellites
  • Deuterium/hydrogen (D/H) ratio for Titan and Saturn
  • Structure and evolution of Saturn’s rings

The UVIS has two spectrographic channels that provide images and spectra covering the ranges from 56 to 118 nm and 110 to 190 nm. A third optical path with a solar blind CsI photocathode is used for high signal-to-noise-ratio stellar occultations by rings and atmospheres. A separate hydrogen-deuterium absorption cell (HDAC) measures the relative abundance of D/H from their Lyman-alpha emission.