• Watching Summer Clouds on Titan

    From baalke@1:2320/100 to sci.space.news on Fri Nov 4 23:09:28 2016
    From Newsgroup: sci.space.news


    http://www.jpl.nasa.gov/news/news.php?feature=6670

    Watching Summer Clouds on Titan
    Jet Propulsion Laboratory
    November 4, 2016

    NASA's Cassini spacecraft watched clouds of methane moving across the
    far northern regions of Saturn's largest moon, Titan, on Oct. 29 and
    30, 2016.

    Several sets of clouds develop, move over the surface and fade during
    the course of this movie sequence, which spans 11 hours, with one frame
    taken every 20 minutes. Most prominent are long cloud streaks that lie
    between 49 and 55 degrees north latitude. While the general region of
    cloud activity is persistent over the course of the observation, individual streaks appear to develop then fade. These clouds are measured to move
    at a speed of about 14 to 22 miles per hour (7 to 10 meters) per second.

    There are also some small clouds over the region of small lakes farther
    north, including a bright cloud between Neagh Lacus and Punga Mare, which
    fade over the course of the movie. This small grouping of clouds is moving
    at a speed of about 0.7 to 1.4 miles per hour (1 to 2 meters) per second.

    Time-lapse movies like this allow scientists to observe the dynamics of
    clouds as they develop, move over the surface and fade. A time-lapse movie
    can also help to distinguish between noise in images (for example from
    cosmic rays hitting the detector) and faint clouds or fog.

    In 2016, Cassini has intermittently observed clouds across the northern mid-latitudes of Titan, as well as within the north polar region -- an
    area known to contain numerous methane/ethane lakes and seas see PIA19657
    and PIA17655. However, most of this year's observations designed for cloud monitoring have been short snapshots taken days, or weeks, apart. This observation provides Cassini's best opportunity in 2016 to study short-term cloud dynamics.

    Models of Titan's climate have predicted more cloud activity during early northern summer than what Cassini has observed so far, suggesting that
    the current understanding of the giant moon's changing seasons is incomplete.

    The mission will continue monitoring Titan's weather around the 2017 summer solstice in Titan's northern hemisphere.

    The movie was acquired using the Cassini narrow-angle camera using infrared filters to make the surface and tropospheric methane clouds visible.

    The Cassini mission is a cooperative project of NASA, ESA (the European
    Space Agency) and the Italian Space Agency. The Jet Propulsion Laboratory,
    a division of the California Institute of Technology in Pasadena, manages
    the mission for NASA's Science Mission Directorate, Washington. The Cassini orbiter and its two onboard cameras were designed, developed and assembled
    at JPL. The imaging operations center is based at the Space Science Institute in Boulder, Colorado.

    For more information about the Cassini-Huygens mission visit http://saturn.jpl.nasa.gov
    and http://www.nasa.gov/cassini. The Cassini imaging team homepage is
    at http://ciclops.org.

    News Media Contact
    Preston Dyches
    Jet Propulsion Laboratory, Pasadena, Calif.
    818-354-7013
    preston.dyches@jpl.nasa.gov

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