* Astronomy

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RE: Enceladus

Blobrana · L

Enceladus weather: Snow flurries and perfect powder for skiing

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.
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Blobrana · L

Saturn's Moon Enceladus Spreads Its Influence

The small, dynamic moon spews out dramatic plumes of water vapour 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 vapour created by Enceladus encircling Saturn. The torus is more than 600,000 kilometres across and about 60,000 kilometres thick. It appears to be the source of water in Saturn's upper atmosphere.
Though it is enormous, the cloud had not been seen before because water vapour is transparent at most visible wavelengths of light. But Herschel could see the cloud with its infrared detectors.
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Blobrana · L

This image of Saturn's Moon Enceladus was taken by the Cassini spaceprobe on the 13th September, 2011 when the spacecraft was approximately 49,788 kilometres away.

Expand (211kb, 1024 x 1024)
Credit: NASA/JPL/Space Science Institute

The image was taken using the CL1 and CL2 filters.

Blobrana · L

Herschel confirme: Encelade fait la pluie sur Saturne

Utilisant les données du télescope infrarouge Herschel de l'ESA, une équipe internationale incluant cinq chercheurs de l'Observatoire de Paris et du CNRS a résolu le mystère vieux de 15 ans de l'origine de l'eau dans la haute atmosphère de Saturne. Le composé est expulsé sous forme de vapeur et de glace par les geysers et panaches actifs au pôle sud d'Encelade, une des lunes de la planète géante aux anneaux. Le satellite de 500 kilomètres de diamètre rejette ainsi environ 250 kilogrammes d'eau par seconde puis elle s'accumule en un vaste nuage diffus qui dessine un anneau qui entoure Saturne. Lentement, 3 % à 5 % de cette matière finit par retomber dans l'atmosphère de la planète. Encelade constitue ainsi le premier exemple d'un satellite du Système solaire qui influence la composition de son astre parent.
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Blobrana · L

Enceladus is the sixth-largest of the moons of Saturn. It was discovered on the 28th August, 1789, by William Herschel.
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Blobrana · L

Enceladus rains water onto Saturn

ESA's Herschel space observatory has shown that water expelled from the moon Enceladus forms a giant torus of water vapour around Saturn. The discovery solves a 14-year mystery by identifying the source of the water in Saturn's upper atmosphere.
Herschel's latest results mean that Enceladus is the only moon in the Solar System known to influence the chemical composition of its parent planet.
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Blobrana · L

Strongest evidence yet indicates icy Saturn moon hiding salt-water ocean

Samples of icy spray shooting from Saturn's moon Enceladus collected during Cassini spacecraft flybys show the strongest evidence yet for the existence of a large-scale, subterranean salt-water ocean, says a new international study led by the University of Heidelberg and involving the University of Colorado Boulder.
The new discovery was made during the Cassini-Huygens mission to Saturn, a collaboration of NASA, the European Space Agency and the Italian Space Agency. Launched in 1997, the mission spacecraft arrived at the Saturn system in 2004 and has been touring the giant ringed planet and its vast moon system ever since.
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Blobrana · L

Cassini Captures Ocean-Like Spray at Saturn Moon

NASA's Cassini spacecraft has discovered the best evidence yet for a large-scale salt-water reservoir beneath the icy crust of Saturn's moon Enceladus. The data came from the spacecraft's direct analysis of salt-rich ice grains close to the jets ejected from the moon.
Data from Cassini's cosmic dust analyser show the grains expelled from fissures, known as tiger stripes, are relatively small and predominantly low in salt far away from the moon. But closer to the moon's surface, Cassini found that relatively large grains rich with sodium and potassium dominate the plumes. The salt-rich particles have an "ocean-like" composition and indicate that most, if not all, of the expelled ice and water vapour comes from the evaporation of liquid salt water. The findings appear in this week's issue of the journal Nature.
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Blobrana · L

Enceladus named sweetest spot for alien life

Saturn's icy moon Enceladus is emerging as the most habitable spot beyond Earth in the Solar System for life as we know it, scientists said last week at a meeting of the Enceladus Focus Group at the SETI Institute in Mountain View, California.
But it may be too late to get a mission there the fast way, via a gravity boost from Jupiter. This would cut the journey time from ten years to as little as seven, but the next Jupiter-assist window hits its peak in 2015-17, and then closes until the 2030s.