PIA11672 Giant Propeller in A Ring.jpg

Description
English: An unusually large propeller feature is detected just beyond the Encke Gap in this Cassini image of Saturn's outer A ring taken a couple days after the planet's August 2009 equinox.

The unique geometry of equinox has thrown into relief small moonlets within the rings and the structures they create around them. Propeller-like features, a few kilometers long, centered on and created by the action of small embedded moonlets only about 100 meters across, were discovered early in the mission (see Locating the Propellers and Four Propellers). These previous findings constituted the first recognition of the presence in Saturn's rings of bodies bigger than the largest ring particles (about 10 meters, or 30 feet, across) but smaller than the 8-kilometer-wide (5-mile-wide) ring moon, Daphnis, in the outer A ring.

From the 350-kilometer (220-mile) length of the shadow cast by this 130-kilometer-long (80-mile-long) propeller, the heights of these features above the ring plane have been measured to reach about 200 meters (650 feet), indicating the moonlet responsible for the propeller in this image is likely to be 400 meters (1,300 feet) across. (A second version of the image, cropped and zoomed-in by a factor of two, has also been included.)

A previously released early-equinox image also had revealed a moonlet in the outer B ring about 400 meters (1,300 feet) across (see A Small Find Near Equinox).

Cassini scientists have tracked several individual propeller moons embedded in Saturn’s A ring over several years. The A ring is the outermost of Saturn's main rings. Imaging scientists nicknamed the propeller shown here "Earhart" after the American aviatrix Amelia Earhart. See Sunlit Propeller for an earlier view of this propeller.

It has since become a growing realization resulting from Cassini's exploration of Saturn that the objects forming Saturn's rings very likely span the full spectrum of sizes, from the smallest dust-sized ring particles to the ring-moons like Daphnis and 29-kilometer-wide (18-mile-wide) Pan -- a significant advance in divining the origin of Saturn's rings.

The novel illumination geometry that accompanies equinox lowers the sun's angle to the ring plane, significantly darkens the rings, and causes out-of-plane structures to cast long shadows across the rings. (The rings have been brightened in this image to enhance visibility.) These scenes are possible only during the few months before and after Saturn's equinox which occurs only once in about 15 Earth years.

This view looks toward the northern side of the rings from about 20 degrees above the ring plane.

The image was taken in visible light with the Cassini spacecraft narrow-angle camera on Aug. 13, 2009. The view was acquired at a distance of approximately 1.2 million kilometers (746,000 miles) from Saturn and at a sun-Saturn-spacecraft, or phase, angle of 87 degrees. Image scale is 7 kilometers (4 miles) per pixel.
Date
Source http://photojournal.jpl.nasa.gov/catalog/PIA11672
Author NASA/JPL/Space Science Institute.
Shuttle.svg
This image or video was catalogued by Jet Propulsion Laboratory of the United States National Aeronautics and Space Administration (NASA) under Photo ID: PIA11672.

This tag does not indicate the copyright status of the attached work. A normal copyright tag is still required. See Commons:Licensing for more information.

български | català | čeština | Deutsch | English | español | فارسی | français | galego | magyar | Հայերեն | Bahasa Indonesia | italiano | 日本語 | македонски | മലയാളം | Nederlands | polski | português | русский | sicilianu | Türkçe | українська‎ | 中文 | 中文(简体)‎ | +/−

Licensing[ ]

Public domain
This file is in the public domain in the United States because it was solely created by JPL Image Use Policy.)
NASA logo.svg
Dialog-warning.svg
Warnings:

  • Use of 14 CFR 1221.
  • The NASA website hosts a large number of images from the Soviet/ Russian space agency, and other non-American space agencies. These are not necessarily in the public domain.
  • Materials based on Hubble Space Telescope data may be copyrighted if they are not explicitly produced by the Cc-Hubble}}.
  • The [2]
  • Images featured on the [3]
  • The photo gallery FAQ states that all of the images in the photo gallery are in the public domain "Unless otherwise noted."

Original upload log[ ]

The original description page was here. All following user names refer to en.wikipedia.
  • 2010-07-17 00:59 Kwamikagami 456×432× (24574 bytes) {{Information |Description={{en|1=The Cassini spacecraft captured this image of a small object in the outer portion of Saturn's B ring casting a shadow on the rings as Saturn approaches its August 2009 equinox. }} |Source=http://photojournal