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.

Read about a magnetar NASA scientists believe is orbiting the supermassive black hole at the center of the Milky Way, Sagittarius A.

Learn about NASA’s search for the ‘Crucible of Life’.

Read about the search for the missing link in black hole evolution.

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The Twin Jet Nebula Flies on the Wings of a Cosmic Butterfly

Twin iridescent jets of gas stream outward from a binary planetary nebula at over 1 million kilometers (621,400 miles) an hour.

 Seemingly flapping cosmic wings of gas, the Butterfly Nebula has only been flying across the constellation Ophiuchus for around 1,200 years. A binary star system with suns in the final days of their life cycles, astronomers are currently studying this unusual celestial object in hopes of understanding the processes creating such stunning beauty.

Seemingly flapping cosmic wings of gas, the Butterfly Nebula has only been flying across the constellation Ophiuchus for around 1,200 years. A binary star system with suns in the final days of their life cycles, astronomers are currently studying this unusual celestial object in hopes of understanding the processes creating such stunning beauty.

Space news (September 24, 2015) –

First recorded flying across the constellation Ophiuchus – about 2,100 light-years from Earth – by Rudolph Minkowski in 1947, the Twin Jet Nebula (PN M2-9), or Wings of a Butterfly Nebula, is a remarkably complex and stunningly beautiful 1,200-year-old bipolar planetary nebula.

Rudolph Leo Bernhard Minkowski 28 May 1895 1961 Bruce Medalist 4 January 1976
Rudolph Leo Bernhard Minkowski
28 May 1895 1961 Bruce Medalist 4 January 1976 Image credit: phys-astro.sonoma.edu

A bipolar nebula composed of an average star between 1 to 1.4 solar masses nearing the end of its life cycle and a smaller white dwarf between 0.6 to 1.0 solar masses that orbit a common center of mass. The Twin Jet Nebula gets its name from the shape of its two lobes, which look like butterfly wings to many viewers. 

Astrophysicists think the shape of the wings (lobes) is mainly due to the unusual motion of the larger star and white dwarf around their common center of mass. Orbiting each other in around 100 years, the smaller white dwarf is thought to have stripped gas away from its larger companion star, which then formed an expanding ring of material around the stars far too small to be seen by Hubble.

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This disk of material was then stretched into the shape of two lobes resembling two butterfly wings, rather than a uniform sphere, due to the unusual motion of the two stars around their center of mass. The faint patches of blue within the wings, starting near the binary star system and extending outward horizontally, are twin jets of gas streaming outward at over 1 million kilometers an hour. These jets slowly change their orientation, precessing across the lobes (wings) as the two stars orbit each other.

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Astronomers have noted a west to east, left to right, the precession of the Butterfly Nebula. Credit: NASA/Hubble

Astrophysicists are now taking a closer look at the Twin Jet Nebula, and other bipolar nebulae, to try to determine if such systems always contain two stars orbiting a common center of mass. Currently, astronomers are discussing this possibility, and other scenarios possibly leading to the birth and growth of similar celestial objects and other phenomena.

Hubble Sees Supersonic Exhaust From Nebula

Two astronomers working with NASA’s Hubble Space Telescope and the ESO’s New Technology Telescope also recently conducted a study of 130 planetary nebulae. Dr. Brian Rees and Dr. Albert Zijlstra of the University of Manchester in the United Kingdom found the long axis of many bipolar planetary nebulae studied all line up along the plane of the Milky Way. This alignment could have something to do with the magnetic field of the bulge at the center of our galaxy they think. You can read the abstract here.

You can learn more about bipolar nebulae here.

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Hubble Telescope Views Young Globular Cluster NGC 1783

One of the largest globular clusters in the Large Magellanic Cloud

 This new Hubble image of NGC 1783, taken with the Advanced Camera for Survey (ACS), shows the typical shape of young globular clusters viewed during the human journey to the beginning of space and time. Image credit NASA.

This new Hubble image of NGC 1783, taken with the Advanced Camera for Survey (ACS), shows the typical shape of young globular clusters viewed during the human journey to the beginning of space and time. Image credit NASA.

Space news (September 20, 2015) – 160,000 light-years from Earth toward the constellation Dorado –

Held in the grip of its own gravity, globular cluster NGC 1783 orbits the Milky Way as part of the Large Magellanic Cloud, a region of space filled with star-forming regions like the Tarantula Nebula and LHA 120-N 11.

Lying in the southern hemisphere constellation Dorado, the typical symmetrical form and dense collection of suns near the center of NGC 1783 was first recorded by John Herschel around 1835.

Astrophysicists studied the color and brightness of individual suns within globular cluster NGC 1783 to estimate its age and history of star formation. Measurements indicate that despite its typical distribution of stars and shape this larger star cluster is only about 1.5 billion years old and during its lifespan has undergone at least two-star forming periods separated by 50 to 100 million years. Typically globular clusters viewed are several billion years of age.

The highs and lows of star formation in a globular cluster gives astrophysicists an indication of the density of gas available for new stars to form during its life span. During periods when dense gas is available for star formation, the most massive stars explode as supernovae, blowing away the gas needed for new stars to form. The reservoir of gas for new star formation is then replenished by less massive stars which live longer and die less violently.  Once the reservoir of gas flows to denser, central regions of a star cluster, the second phase of star formation takes place, and a massive star with a short life spans once again blow off the gas. Astrophysicists think this cycle continues until the gas leftover can no longer sustain the formation of new stars.

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Radio Phoenix Erupts After Collision Between Galaxy Clusters in Abell 1033

Produced by shockwaves compressing and re-energizing dormant clouds of electrons that shine at radio frequencies

 High-energy X-rays detected by NASA's Chandra X-ray Observatory are seen in pink in the image above, while radio data from NSF's Karl Jansky Very Large Array (VLA) is green. A map of the density of galaxies in the region, seen in blue was obtained by analysis of optical data.

High-energy X-rays detected by NASA’s Chandra X-ray Observatory are seen in pink in the image above, while radio data from NSF’s Karl Jansky Very Large Array (VLA) is green. A map of the density of galaxies in the region, seen in blue was obtained by analysis of optical data.

Space news (September 14, 2015) – 1.6 billion light-years from Earth in Abell 1033 –

Astronomers and astrophysicists looking at data provided by NASA’s Chandra X-ray Observatory, the Sloan Digital Sky Survey (SDSS), NSF’s Karl Jansky Very Large Array (VLA) and the Westerbork Synthesis Radio Telescope have detected what they refer to as a “Radio Phoenix“.

Consisting of an array of 14 radio telescopes with a diameter of 25 meters each, the Dutch Westerbork Synthesis Radio Telescope simulates a radio telescope with a diameter of up to 2.7 kilometres. Image credit Universe Awareness
Consisting of an array of 14 radio telescopes with a diameter of 25 meters each, the Dutch Westerbork Synthesis Radio Telescope simulates a radio telescope with a diameter of up to 2.7 kilometers. Image credit Universe Awareness

A Radio Phoenix as seen in the multiwavelength photo at the top of the page is a cloud of bright radio emission of high-energy electrons thousands of light-years across that originally erupted from the supermassive black hole near the center of Abell 1033. As the cloud expanded it faded over time as electrons within lost energy, until millions of years later it was reborn when shockwaves from a collision between Abell 1033 and another galaxy cluster compressed and re-energized the electrons, causing the cloud to shine as a Radio Phoenix.

This Radio Phoenix is expected to be reborn for only a few tens of million of years, just a blink of an eye on cosmic scales. The intense density and pressures in the region and powerful magnetic fields near the center of Abell 1033 will cause it to eventually fade into darkness.

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NASA Releases New View of Iconic Pillars of Creation in 3D

Revealing protostars and giant clouds of gas and dust where new stars were born

This visualisation of the three-dimensional structure of the Pillars of Creation within the star formation region Messier 16 (also called the Eagle Nebula) is based on new observations of the object using the MUSE instrument on ESO’s Very Large Telescope in Chile. The pillars actually consist of several distinct pieces on either side of the star cluster NGC 6611. In this illustration, the relative distance between the pillars along the line of sight is not to scale. Image Credit: European Southern Observatory
This visualization of the three-dimensional structure of the Pillars of Creation within the star formation region Messier 16 (also called the Eagle Nebula) is based on new observations of the object using the MUSE instrument on ESO’s Very Large Telescope in Chile. The pillars actually consist of several distinct pieces on either side of the star cluster NGC 6611. In this illustration, the relative distance between the pillars along the line of sight is not to scale.
Image Credit: European Southern Observatory

Space news (August 18, 2015) – 7,000 light-years away toward constellation Serpens (The Serpent); the iconic Pillars of Creation

Astronomers working with the Multi Unit Spectroscopic Explorer (MUSE) on the European Southern Observatory’s (ESO) Very Large Telescope (VLT) have released the first 3D image of the Pillars of Creation in the Eagle Nebula (M16 or Messier 16).

 The iconic first image of the Pillars of Creation, to the left in the image below, was taken by the Hubble Space Telescope in 1995, but the latest image shown on the right below is both bigger and shows new details. An immense jet from a young star, intense radiation and stellar winds from brilliant O and B type suns sculpture the dusty Pillars of Creation over time. Three million years in the future the pillars will be totally evaporated by these forces.
Undersea coral? Enchanted castles? Space serpents? These eerie, dark pillar-like structures are actually columns of cool interstellar hydrogen gas and dust that are also incubators for new stars. The pillars protrude from the interior wall of a dark molecular cloud like stalagmites from the floor of a cavern.

The Pillars of Creation are a stellar feature that is more common than people first assume. Similar structures and shapes have been and are quite frequently seen during the human journey to the beginning of space and time. The columns of the Pillars of Creation were formed when intense radiation and stellar winds from huge, newly formed blue-white O and B suns blew away less dense material in the region of space surrounding them.

A study has shown the very top of the left pillar in the image is pointing toward us and sitting on top of another pillar behind nearby stellar cluster NGC 6611. This top portion of the left pillar is bearing the majority of withering radiation from nearby stars and this is why it looks brighter to our eyes compared to the other pillars.

I’m impressed by how transitory these structures are. They are actively being ablated away before our very eyes. The ghostly bluish haze around the dense edges of the pillars is material getting heated up and evaporating away into space. We have caught these pillars at a very unique and short-lived moment in their evolution,” explained Paul Scowen of Arizona State University in Tempe. He and astronomer Jeff Hester, formerly of Arizona State University, led the original Hubble observations of the Eagle Nebula.

Scowen said. “The gas is not being passively heated up and gently wafting away into space. The gaseous pillars are actually getting ionized, a process by which electrons are stripped off of atoms, and heated up by radiation from the massive stars. And then they are being eroded by the stars’ strong winds and a barrage of charged particles, which are literally sandblasting away the tops of these pillars.   

The denser material left behind acted as a shield against the harsh, withering glare of nearby brilliant young stars, and formed the shape of the region. The dark “tails” or “elephant trunks” viewed as the dark body of the pillars point away from the intense radiation and stellar winds of nearby brilliant stars.

Now, astronomers plan on studying how newborn O and B stars in NGC 6611 influence the growth of further generations of stars. Previous studies have detected protostars forming within the clouds of NGC 6611. The latest study also provided evidence for protostars forming in the middle and left clouds of the Pillars of Creation and there are also probably other protostars and young stars hidden from view within the region.

Astronomers want to study star-forming regions like the Pillars of Creation in order to better understand the conditions in which stars like our own Sun formed. Current evidence points to the early solar system being bombarded with radioactive shrapnel from a nearby supernova. This indicates we formed in a star-forming region with young stars massive enough to produce powerful ionizing radiation like we see in the Eagle Nebula.

“That’s the only way the nebula from which the sun was born could have been exposed to a supernova that quickly, in the short period of time that represents, because supernovae only come from massive stars, and those stars only live a few tens of millions of years,” Scowen explained. “What that means is when you look at the environment of the Eagle Nebula or other star-forming regions, you’re looking at exactly the kind of nascent environment that our sun formed in.”

You can find out more about the MUSE here.

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Read about the surprises planetary scientists discovered during the recent flyby of NASA’s New Horizons spacecraft.

Learn more about how exploding stars seed the universe with the building blocks of life.

Read about how NASA scientists used the Hubble Space Telescope to map temperatures and water vapor on “a hot Jupiter-class exoplanet“.