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Posts Tagged ‘Enceladus’

NASA Space Assets Detect Ocean Inside Saturn Moon


Illustration. Image credit: NASA/JPL-Caltech

Illustration. Image credit: NASA/JPL-Caltech

NASA’s Cassini spacecraft and Deep Space Network have uncovered evidence Saturn’s moon Enceladus harbors a large underground ocean of liquid water, furthering scientific interest in the moon as a potential home to extraterrestrial microbes.

Researchers theorized the presence of an interior reservoir of water in 2005 when Cassini discovered water vapor and ice spewing from vents near the moon’s south pole. The new data provide the first geophysical measurements of the internal structure of Enceladus, consistent with the existence of a hidden ocean inside the moon. Findings from the gravity measurements are in the Friday, April 4 edition of the journal Science.

“The way we deduce gravity variations is a concept in physics called the Doppler Effect, the same principle used with a speed-measuring radar gun,” said Sami Asmar of NASA’s Jet Propulsion Laboratory in Pasadena, Calif., a coauthor of the paper. “As the spacecraft flies by Enceladus, its velocity is perturbed by an amount that depends on variations in the gravity field that we’re trying to measure. We see the change in velocity as a change in radio frequency, received at our ground stations here all the way across the solar system.”

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Cassini Significant Events 03/21/2012 – 03/27/2012


The most recent spacecraft tracking and telemetry data were collected on March 28 using the Deep Space Network’s 70 meter Station 43 at Canberra, Australia; data from the Enceladus E-17 encounter were captured successfully. Aside from the issue in work with the Ultrastable Oscillator (see the Jan. 5, 2012 Significant Events), the Cassini spacecraft is in an excellent state of health and all subsystems are operating normally. Information on the present position of the Cassini spacecraft may be found on the “Present Position” page at: http://saturn.jpl.nasa.gov/mission/presentposition/.

The Enceladus encounter E-17 occurred Tuesday, and by the end of the day, all the encounter observations resided as telemetry on Cassini’s Solid-State Recorder. The playback to Earth didn’t begin until Wednesday; it will be listed among next week’s significant events. The E-17 webpage will include the data as they become available: http://saturn.jpl.nasa.gov/mission/flybys/enceladus20120306/

Full Story: http://saturn.jpl.nasa.gov/news/significantevents/significantevents20120330/

Saturn’s Rings and Enceladus

February 8, 2012 Leave a comment

Image Credits: NASA/JPL–Caltech/Space Science Institute

Image Credits: NASA/JPL–Caltech/Space Science Institute

A crescent Enceladus appears with Saturn’s rings in this Cassini spacecraft view of the moon.

The famed jets of water ice emanating from the south polar region of the 504 km-diameter moon are faintly visible.

They appear as a small white blur below the dark pole, down and to the right of the illuminated part of the moon’s surface. The image’s contrast was enhanced to increase their visibility.

The sunlit terrain seen here is on the trailing hemisphere of Enceladus; north is up. This view looks toward the northern, sunlit side of the rings from just above the ringplane. The image was taken with Cassini’s narrow-angle camera on 4 January at a distance of 291 000 km from Enceladus. Image scale is about 2 km per pixel.

Full Story: http://www.esa.int/export/esaSC/SEMZ46WX7YG_index_0.html

New Findings on Saturn’s Moons & Magnetosphere

December 31, 2011 Leave a comment

Scientists have been puzzled by periodic bursts of radiation, known as the Saturn kilometric radiation (SKR), that occur in the planet’s magnetosphere. These emissions occur at a rate that is close to, but not quite the same as, the rate at which the planet rotates.

New observations from the Cassini spacecraft’s flybys of Saturn’s moon Enceladus in 2008 are revealing new details about the plasma environment around Enceladus and how it may affect Saturn’s magnetosphere. These observations could also shed some light on the SKR rotation rate.

Enceladus sprays out a plume of water vapor and ice from its south pole. This plume produces ionized gas that is a significant source of plasma for Saturn’s magnetosphere and E ring. Observations described by Morooka et al. show that the plume also produces negatively charged dust that affects the motion of the plasma in this region. This dust-plasma interaction impacts the dynamics of Saturn’s magnetosphere, possibly influencing the rate of SKR emissions.

Full Story: http://www.agu.org/news/press/jhighlight_archives/2011/2011-12-30.shtml#one

Enceladus Weather – Snow Flurries & Perfect Powder

October 5, 2011 Leave a comment

Global and high resolution mapping of Enceladus confirms that the weather forecast for Saturn’s unique icy moon is set for ongoing snow flurries.  The superfine ice crystals that coat Enceladus’s surface would make perfect powder for skiing, according to Dr Paul Schenk of the Lunar and Planetary Institute (Houston, Texas), who will present the results at the EPSC-DPS Joint Meeting 2011 in Nantes, France on Monday 3rd October.

Mapping of global colour patterns and measurements of surface layer thicknesses show that ice particles fall back onto the surface of Enceladus in a predictable pattern.  Mapping of these deposits indicate that the plumes and their heat source are relatively long-lived features lasting millennia and probably tens of million years or more, and have blanketed areas of the surface in a thick layer of tiny ice particles.

“The discovery by instruments aboard the Cassini orbiter that there’s a currently active plume of icy dust and vapour from Enceladus has revolutionized planetary science,” says Schenk.  “Earlier this year, we published work that showed material from Enceladus’s plumes coats the surfaces of Saturn’s icy moons. Now, we’ve uncovered two lines of evidence that point to thick deposits of plume material coating the surface of Enceladus itself.”

Full Story: http://www.europlanet-eu.org/outreach/index.php?option=com_content&task=view&id=351&Itemid=1

Saturn’s Moon Enceladus Spreads Its Influence

September 22, 2011 Leave a comment

Credit: NASA/JPL/Space Science Institute

Credit: NASA/JPL/Space Science Institute

Chalk up one more feat for Saturn’s intriguing moon Enceladus. The small, dynamic moon spews out dramatic plumes of water vapor and ice — first seen by NASA’s Cassini spacecraft in 2005. It possesses simple organic particles and may house liquid water beneath its surface. Its geyser-like jets create a gigantic halo of ice, dust and gas around Enceladus that helps feed Saturn’s E ring. Now, thanks again to those icy jets, Enceladus is the only moon in our solar system known to influence substantially the chemical composition of its parent planet.

In June, the European Space Agency announced that its Herschel Space Observatory, which has important NASA contributions, had found a huge donut-shaped cloud, or torus, of water vapor created by Enceladus encircling Saturn. The torus is more than 373,000 miles (600,000 kilometers) across and about 37,000 miles (60,000 kilometers) thick. It appears to be the source of water in Saturn’s upper atmosphere.

Full Story: http://saturn.jpl.nasa.gov/news/cassinifeatures/feature20110921/