Icy Hot: Europa’s Frozen Crust Could Be Warmer Than We Thought

Monday, May 2, 2016

Icy Hot: Europa’s Frozen Crust Could Be Warmer Than We Thought

Icy Hot: Europa’s Frozen Crust Could Be Warmer Than We Thought:

Europa's cracked, icy surface imaged by NASA's Galileo spacecraft in 1998. Credit: NASA/JPL-Caltech/SETI Institute.

All the worlds may be ours except Europa but that only makes the ice-covered moon of Jupiter all the more intriguing. Beneath Europa's thin crust of ice lies a tantalizing global ocean of liquid water somewhere in the neighborhood of 100 kilometers deep—which adds up to more liquid water than is on the entire surface of the Earth. Liquid water plus a heat source(s) to keep it liquid plus the organic compounds necessary for life and...well, you know where the thought process naturally goes from there.And now it turns out Europa may have even more of a heat source than we thought. Yes, a big component of Europa's water-liquefying warmth comes from tidal stresses enacted by the massive gravity of Jupiter as well as from the other large Galilean moons. But exactly how much heat is created within the moon's icy crust as it flexes has so far only been loosely estimated. Now, researchers from Brown University in Providence, RI and Columbia University in New York City have modeled how friction creates heat within ice under stress, and the results were surprising.Although 3,100-km-wide Europa is coated in ice and technically has the smoothest surface in the Solar System, it's far from featureless. Its frozen crust features enormous regions of broken "chaos terrain" and is covered in long, crisscrossing fractures filled with reddish-brown material (which may be a form of sea salt), as well as crumpled, mountain-like ridges that appear curiously fresh.These ridges are thought to be a result of a form of tectonics, except not with plates of rock like on Earth but rather shifting slabs of frozen water. But where the energy needed to drive that process is coming from—and what happens to all the frictional heat created during it—isn't well known."People have been using simple mechanical models to describe the ice," said geophysicist Christine McCarthy, Lamont Assistant Research Professor at Columbia University who led the research while a graduate student at Brown University. "They weren't getting the kinds of heat fluxes that would create these tectonics. So we ran some experiments to try to understand this process better."By mechanically subjecting ice samples to various forms of pressure and stress, similar to the conditions that would be found on Europa as it orbits Jupiter, the researchers found that most of the heat is generated within deformities in the ice, rather than between the individual grains as was previously thought. This difference means there's likely a lot more heat moving through Europa's ice layers, which would affect both its behavior and its thickness."Those physics are first order in understanding the thickness of Europa's shell," said Reid Cooper, Earth science professor and McCarthy's research partner at Brown. "In turn, the thickness of the shell relative to the bulk chemistry of the moon is important in understanding the chemistry of that ocean. And if you're looking for life, then the chemistry of the ocean is a big deal."When it comes to Europa's icy crust there have traditionally been two camps of thought: the thin-icers and the thick-icers. Thin-icers estimate the moon's crust to be at most only a few kilometers thick—possibly coming very close to the surface in places, if not breaking through entirely—while those in the thick-ice camp think it could be tens of times thicker. While there are data to support both hypotheses, it remains to be seen which these new findings will best support.Luckily we won't have to wait terribly long to find out how thick the moon's icy crust really is. A recently-approved NASA mission will launch to Europa in the 2020s to explore its surface, interior composition, and potential habitability. The mission may (i.e., should) also include a lander, although of what fashion has yet to be determined. But when the data from that mission do finally come in, many of our long-standing questions about this mystifying icy world will finally be answered.The team's research is published in the June 1 issue of Earth and Planetary Science Letters.Source: PhysOrg.com

The post Icy Hot: Europa’s Frozen Crust Could Be Warmer Than We Thought appeared first on Universe Today.

FASHION WEEK - USA Fashion and Music News
HOLLYWOOD NEWS - Hollywood News Blogger
PINTEREST ACROSS THE UNIVERSE - Google Images Nasa Images
LAST FM - Download Music Legally Direct From Artist
WOMEN COMMUNITY - Women Communty Photography Videos Beauty
DISNEY CHANNEL - Photos and Music News
BABY JUSTIN BIEBER - Google Images Google News
LADY GAGA - Google Images Google News
ACROSS THE UNIVERSE - Google Images Universe Pictures
VICTORIA´S SECRET COMMUNITY - Victoria´s Secret Fashion Show Photos

No comments:

Post a Comment

NASA Photos Photography

The National Aeronautics and Space Administration (NASA) is the United States government agency responsible for the civilian space program as well as aeronautics and aerospace research. President Dwight D. Eisenhower established the National Aeronautics and Space Administration (NASA) in 1958 with a distinctly civilian (rather than military) orientation encouraging peaceful applications in space science. The National Aeronautics and Space Act was passed on July 29, 1958, disestablishing NASA's predecessor, the National Advisory Committee for Aeronautics (NACA). The new agency became operational on October 1, 1958.

UFO SIGHTINGS PHOTO PHOTOGRAPHY

The Oxford English Dictionary defines a UFO as "An unidentified flying object; a 'flying saucer'." The first published book to use the word was authored by Donald E. Keyhoe. The acronym "UFO" was coined by Captain Edward J. Ruppelt, who headed Project Blue Book, then the USAF's official investigation of UFOs. He wrote, "Obviously the term 'flying saucer' is misleading when applied to objects of every conceivable shape and performance. For this reason the military prefers the more general, if less colorful, name: unidentified flying objects. UFO (pronounced Yoo-foe) for short." Other phrases that were used officially and that predate the UFO acronym include "flying flapjack", "flying disc", "unexplained flying discs", "unidentifiable object", and "flying saucer". The phrase "flying saucer" had gained widespread attention after the summer of 1947. On June 24, a civilian pilot named Kenneth Arnold reported seeing nine objects flying in formation near Mount Rainier. Arnold timed the sighting and estimated the speed of discs to be over 1,200 mph (1,931 km/h). At the time, he described the objects' shape as being somewhat disc-like or saucer-like, leading to newspaper accounts of "flying saucers" and "flying discs". In popular usage the term UFO came to be used to refer to claims of alien spacecraft. and because of the public and media ridicule associated with the topic, some investigators prefer to use such terms as unidentified aerial phenomenon (or UAP) or anomalous phenomena, as in the title of the National Aviation Reporting Center on Anomalous Phenomena (NARCAP).

UFO PHOTO PHOTOGRAPHY

UFO - Unidentified Flying Object An unidentified flying object, or UFO, in its most general definition, is any apparent anomaly in the sky that is not identifiable as a known object or phenomenon. Culturally, UFOs are associated with claims of visitation by extraterrestrial life or government-related conspiracy theories, and have become popular subjects in fiction. While UFOs are often later identified, sometimes identification may not be possible owing to the usually low quality of evidence related to UFO sightings (generally anecdotal evidence and eyewitness accounts). Stories of fantastical celestial apparitions have been told since antiquity, but the term "UFO" (or "UFOB") was officially created in 1953 by the United States Air Force (USAF) to serve as a catch-all for all such reports. In its initial definition, the USAF stated that a "UFOB" was "any airborne object which by performance, aerodynamic characteristics, or unusual features, does not conform to any presently known aircraft or missile type, or which cannot be positively identified as a familiar object." Accordingly, the term was initially restricted to that fraction of cases which remained unidentified after investigation, as the USAF was interested in potential national security reasons and/or "technical aspects" (see Air Force Regulation 200-2). During the late 1940s and through the 1950s, UFOs were often referred to popularly as "flying saucers" or "flying discs". The term UFO became more widespread during the 1950s, at first in technical literature, but later in popular use. UFOs garnered considerable interest during the Cold War, an era associated with a heightened concern for national security. Various studies have concluded that the phenomenon does not represent a threat to national security nor does it contain anything worthy of scientific pursuit (e.g., 1951 Flying Saucer Working Party, 1953 CIA Robertson Panel, USAF Project Blue Book, Condon Committee).

Photos of Nature | Nature Photography What is The Universe

Photos of Nature | Nature Photography What is The Universe

Monday, May 2, 2016