lundi 11 septembre 2017

Last Enceladus Plume Observation & So Far from Home










NASA - Cassini International logo.

Sept. 11, 2017


This movie sequence of images is from the last dedicated observation of the Enceladus plume by NASA's Cassini spacecraft.

The images were obtained over approximately 14 hours as Cassini's cameras stared at the active, icy moon. The view during the entire sequence is of the moon's night side, but Cassini's perspective Enceladus shifts during the sequence. The movie begins with a view of the part of the surface lit by reflected light from Saturn and transitions to completely unilluminated terrain. The exposure time of the images changes about halfway through the sequence, in order to make fainter details visible. (The change also makes background stars become visible.)

The images in this movie sequence were taken on Aug. 28, 2017, using Cassini's narrow-angle camera. The images were acquired at a distance from Enceladus that changed from 684,000 to 539,000 (1.1 million to 868,000 kilometers). Image scale changes during the sequence, from 4 to 3 miles (7 to 5 kilometers) per pixel.

So Far from Home


With this view, Cassini captured one of its last looks at Saturn and its main rings from a distance. The Saturn system has been Cassini's home for 13 years, but that journey is nearing its end.

Cassini has been orbiting Saturn for nearly a half of a Saturnian year but that journey is nearing its end. This extended stay has permitted observations of the long-term variability of the planet, moons, rings, and magnetosphere, observations not possible from short, fly-by style missions.

When the spacecraft arrived at Saturn in 2004, the planet's northern hemisphere, seen here at top, was in darkness, just beginning to emerge from winter (see PIA06164). Now at journey's end, the entire north pole is bathed in the continuous sunlight of summer.

Images taken on Oct. 28, 2016 with the wide angle camera using red, green and blue spectral filters were combined to create this color view. This view looks toward the sunlit side of the rings from about 25 degrees above the ringplane.

The view was acquired at a distance of approximately 870,000 miles (1.4 million kilometers) from Saturn. Image scale is 50 miles (80 kilometers) per pixel.

Cassini Grand Finale

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 Caltech 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.

Related link:

PIA06164: https://photojournal.jpl.nasa.gov/catalog/PIA06164

For more information about the Cassini-Huygens mission visit https://saturn.jpl.nasa.gov and https://www.nasa.gov/cassini. The Cassini imaging team homepage is at https://ciclops.org and ESA's website: http://www.esa.int/Our_Activities/Space_Science/Cassini-Huygens

Image, Animations, Text,  Credits: NASA/Martin Perez/Tony Greicius/JPL-Caltech/Space Science Institute.

Best regards, Orbiter.ch

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