Analysis of Planetary Data Confirms Evidence of an Ocean of Liquid Water Beneath Ice Shell of Saturn’s moon Enceladus

A liquid environment where alien life could exist 

Illustration of the interior of Saturn's moon Enceladus showing a global liquid water ocean between its rocky core and icy crust. Thickness of layers shown here is not to scale. Image credit: NASA/JPL-Caltech
Illustration of the interior of Saturn’s moon Enceladus showing a global liquid water ocean between its rocky core and icy crust. The thickness of layers shown here is not to scale. Image credit: NASA/JPL-Caltech

Space news (September 29, 2015) – 30 miles above the icy surface of Saturn’s moon Enceladus – 

NASA planetary scientists and astrophysicists studying seven years of Cassini images and gravitational data provided by the Cassini Solstice Mission believe they have proof positive of the existence of a global liquid ocean of water beneath the icy shell of Saturn’s moon Enceladus. 

NASA's Cassini spacecraft continues to orbit near Saturn. Astrophysicists expect to make even more discoveries in the future.
NASA’s Cassini spacecraft continues to orbit near Saturn. Astrophysicists expect to make even more discoveries in the future. Image credit: JPL/NASA.

By carefully mapping craters and other surface features planetary scientists were able to precisely measure changes in the rotation of Enceladus, which indicated a slight wobble in its orbit. A slight wobble they believe is caused by Enceladus not being perfectly round and traveling faster and slower at different times and positions of its orbit around Saturn. This difference in velocity as it orbits the sixth planet from Sol, causes Saturn to gently rock the moon as it rotates on its axis, producing the slight wobble. 

Planetary scientists found the only way they can account for the magnitude of the very small wobble called a libration- of Enceladus in computer simulations, is if a global ocean of liquid water exists beneath its outer ice shell.

“This was a hard problem that required years of observations, and calculations involving a diverse collection of disciplines, but we are confident we finally got it right,” said Peter Thomas, a Cassini imaging team member at Cornell University, Ithaca, New York, and lead author of the paper.

This is in line with previous data obtained by Cassini and interpreted by planetary scientists as a fine spray of water vapor containing icy particles and basic organic molecules erupting from surface fractures near Enceladus’s southern pole region. Astrophysicists believe the global ocean their analysis indicates exists beneath the ice shell of Enceladus is the source of the fine spray and a possible habitat life could develop and survive in.

“If the surface and core were rigidly connected, the core would provide so much dead weight the wobble would be far smaller than we observe it to be,” said Matthew Tiscareno, a Cassini participating scientist at the SETI Institute, Mountain View, California, and a co-author of the paper. “This proves that there must be a global layer of liquid separating the surface from the core,” he said.

Planetary scientists are currently trying to figure out where the energy keeping the global ocean from completely freezing is coming from. At this point, they think tidal forces due to the gravity of Saturn could be producing a lot more energy than previously calculated. 

“This is a major step beyond what we understood about this moon before, and it demonstrates the kind of deep-dive discoveries we can make with long-lived orbiter missions to other planets,” said co-author Carolyn Porco, Cassini imaging team lead at Space Science Institute (SSI), Boulder, Colorado, and visiting scholar at the University of California, Berkeley. “Cassini has been exemplary in this regard.”

Where’s the heat coming from?

The heat energy keeping the global ocean of Enceladus from freezing could be partly coming from geothermal sources on the bottom of the ocean. Cassini is scheduled to pass over Enceladus again on October 28, 2015, at which time it will only be about 30 miles (49 kilometers) above the surface of the moon, which is the closest the spacecraft will come to the surface. Planetary scientists want to pass through the icy spray, again, to collect more data, and hopefully, determine the reasons the global ocean isn’t frozen.

You can read and learn more about Cassini’s mission to Saturn here.

Go here to discover NASA’s mission to the stars and their future plans.

You can learn more about Saturn’s moon Enceladus here.

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Cassini Spacecraft Shows Us Views of the Solar System in Natural Color

Cassini Spacecraft blasts off on its mission to Saturn
Cassini Orbiter blasts off on its mission to Saturn

NASA spacecraft shows us the solar system as it would be seen by human eyes

A breakdown of the onboard instrumentation of the Cassini Orbiter
A breakdown of the onboard instrumentation of the Cassini Orbiter

Astronomy news (2013/12/19) – NASA revealed to the world an image of stunning Saturn taken by the Cassini spacecraft at the Newseum in Washington on Tuesday showing the giant planet as our eyes would view it.

The spectacular image, seen below, is a panoramic composed of 141 wide-angle images, showing us a view 404,880 miles (651,591 kilometers) across of Earth, Venus, Mars, and Saturn and its moons and inner ring system. The image includes all of Saturn’s rings, including the E ring, which is the second ring from the outer edge of the planet’s rings (the distance between the Earth and the Moon would easily fit within the width of the E ring). “In this one magnificent view, Cassini has delivered to us a universe of marvels,” said Carolyn Porco, Cassini’s imaging team lead at the Space Science Institute in Boulder, Colo. “And it did so on a day people all over the world, in unison, smiled in celebration at the sheer joy of being alive on a pale blue dot.”

A real color image taken of Saturn, with Earth, Mars, Venus and a few moons visible
A real color image of Saturn, with Earth, Mars, Venus and a few moons visible

Join the Wave at Saturn Campaign

This spectacular image of Saturn and its moons and rings is part of NASA’s “Wave at Saturn” campaign, which invited people around the United States and the world to take part in a celebration and party on July 19. NASA asked people to take the time to find Saturn in the sky in their part of the world. To say hello to Cassini and the ringed planet by waving across the solar system and loading any pictures they take onto the Internet to be shared with the world. A fun and social way to join the human journey to the beginning of space and time.

The image above shows Earth as the bright blue dot located to the lower right of Saturn. Venus isn’t easily seen in this image and is the bright dot located to the upper left of the giant planet, while Mars is the faint red dot to the left and above Venus. Viewers with good eyes should be able to view seven of Saturn’s moons in the image, including amazing Enceladus just to the left. Take a closer look and you should see icy plumes flying out from Enceladus’s south pole region, which provides the fine, grain-sized icy dust that makes up the E ring.

Saturn’s E-Ring is Visible

Saturn’s E ring appears like a halo surrounding the planet and its inner rings, and the best view of this area is provided by light shining from behind the planet. Astronomers studying Saturn and its rings used enhanced computer programs to improve the contrast and color balance of the pictures. This allowed them to pick out detailed data and evidence which made it possible to trace out the full orbits of smaller moons like Anthe and Methone, for the first time in the history of the human journey to the beginning of space and time. “This mosaic provides a remarkable amount of high-quality data on Saturn’s diffuse rings, revealing all sorts of intriguing structures we are currently trying to understand,” said Matt Hedman, a Cassini participating scientist at the University of Idaho in Moscow. “The E ring shows patterns that likely reflect disturbances from such diverse sources as sunlight and Enceladus’ gravity.”

The astronomers in charge of Cassini usually don’t try to use the instrument to image Earth very often because an unobstructed view of the sun will damage sensitive equipment on the spacecraft. Astronomers had to wait until the sun was hidden behind Saturn, in relation to Cassini, which occurred on July 19, before taking images of Earth and its moon, and the backlit panoramic picture above. “With a long, intricate dance around the Saturn system, Cassini aims to study the Saturn system from as many angles as possible,” said Linda Spilker, Cassini project scientist based at NASA’s Jet Propulsion Laboratory in Pasadena, Calif. “Beyond showing us the beauty of the Ringed Planet, data like these also improve our understanding of the history of the faint rings around Saturn and the way disks around planets form — clues to how our own solar system formed around the sun.”

Cassini has been exploring Saturn and its local region for nine years to date, and NASA has indicated the spacecraft will continue its mission until at least 2017. We will bring you more images of Saturn and data concerning the planet as long as the human journey to Saturn continues.

To view the image, visit: http://www.jpl.nasa.gov/spaceimages/details.php?id=PIA17172.

A new version of the collage of photos shared by the public, with the Saturn system as the backdrop, is available at http://www.jpl.nasa.gov/spaceimages/details.php?id=PIA17679.

More information about Cassini is available at http://www.nasa.gov/cassini and http://saturn.jpl.nasa.gov.

Watch this YouTube video on Cassini and mission results here. https://www.youtube.com/watch?v=X5zcrEze8L4.

Watch this YouTube video on the picture Cassini took of the Earth and Moon https://www.youtube.com/watch?v=d-PlmiKs6Mk.

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