Thursday, June 23, 2011

NASA’s Cassini–Huygens spacecraft has discovered evidence for a large-scale saltwater 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. The study has been published in this week’s edition of the journal Nature.

Data from Cassini’s cosmic dust analyzer show the grains expelled from fissures, known as tiger stripes, are relatively small and usually low in salt far away from the moon. 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 vapor comes from the evaporation of liquid salt-water. When water freezes, the salt is squeezed out, leaving pure water ice behind.

Cassini’s ultraviolet imaging spectrograph also recently obtained complementary results that support the presence of a subsurface ocean. A team of Cassini researchers led by Candice Hansen of the Planetary Science Institute in Tucson, Arizona, measured gas shooting out of distinct jets originating in the moon’s south polar region at five to eight times the speed of sound, several times faster than previously measured. These observations of distinct jets, from a 2010 flyby, are consistent with results showing a difference in composition of ice grains close to the moon’s surface and those that made it out to the E ring, the outermost ring that gets its material primarily from Enceladean jets. If the plumes emanated from ice, they should have very little salt in them.

“There currently is no plausible way to produce a steady outflow of salt-rich grains from solid ice across all the tiger stripes other than salt water under Enceladus’s icy surface,” said Frank Postberg, a Cassini team scientist at the University of Heidelberg in Germany.

The data suggests a layer of water between the moon’s rocky core and its icy mantle, possibly as deep as about 50 miles (80 kilometers) beneath the surface. As this water washes against the rocks, it dissolves salt compounds and rises through fractures in the overlying ice to form reserves nearer the surface. If the outermost layer cracks open, the decrease in pressure from these reserves to space causes a plume to shoot out. Roughly 400 pounds (200 kilograms) of water vapor is lost every second in the plumes, with smaller amounts being lost as ice grains. The team calculates the water reserves must have large evaporating surfaces, or they would freeze easily and stop the plumes.

“We imagine that between the ice and the ice core there is an ocean of depth and this is somehow connected to the surface reservoir,” added Postberg.

The Cassini mission discovered Enceladus’ water-vapor and ice jets in 2005. In 2009, scientists working with the cosmic dust analyzer examined some sodium salts found in ice grains of Saturn’s E ring but the link to subsurface salt water was not definitive. The new paper analyzes three Enceladus flybys in 2008 and 2009 with the same instrument, focusing on the composition of freshly ejected plume grains. In 2008, Cassini discovered a high “density of volatile gases, water vapor, carbon dioxide and carbon monoxide, as well as organic materials, some 20 times denser than expected” in geysers erupting from the moon. The icy particles hit the detector target at speeds between 15,000 and 39,000 MPH (23,000 and 63,000 KPH), vaporizing instantly. Electrical fields inside the cosmic dust analyzer separated the various constituents of the impact cloud.

“Enceladus has got warmth, water and organic chemicals, some of the essential building blocks needed for life,” said Dennis Matson in 2008, Cassini project scientist at NASA’s Jet Propulsion Laboratory in Pasadena, California.

“This finding is a crucial new piece of evidence showing that environmental conditions favorable to the emergence of life can be sustained on icy bodies orbiting gas giant planets,” said Nicolas Altobelli, the European Space Agency’s project scientist for Cassini.

“If there is water in such an unexpected place, it leaves possibility for the rest of the universe,” said Postberg.

Tuesday, August 17, 2010

Plastic surgeon to the stars Dr. Frank Ryan has died in a car accident at age 50. It is reported that the Jeep Ryan was driving crashed over the side of the Pacific Coast Highway and landed on rocks. Lifeguards were first on the scene and unsuccessfully tried to rescue Ryan. It is thought that no other vehicle was involved in the incident.

Dr. Ryan, a celebrity in his own right, performed plastic surgery on several stars including Janice Dickinson, Gene Simmons, Shauna Sand and Adrianne Curry. He appeared on several television shows and became one of the first people to perform plastic surgery on television in 1995.

A representative for Janice Dickinson released a statement about the death of Ryan. She said “Janice is deeply, deeply anguished! She is stunned and wants the world to know what a genius Dr. Ryan was.”

Ryan was traveling with his pet dog at the time of the crash; the dog was found seriously injured in the ocean and was transported to a local veterinarian. Dr. Ryan was pronounced dead at the scene.

Tuesday, August 17, 2010

Plastic surgeon to the stars Dr. Frank Ryan has died in a car accident at age 50. It is reported that the Jeep Ryan was driving crashed over the side of the Pacific Coast Highway and landed on rocks. Lifeguards were first on the scene and unsuccessfully tried to rescue Ryan. It is thought that no other vehicle was involved in the incident.

Dr. Ryan, a celebrity in his own right, performed plastic surgery on several stars including Janice Dickinson, Gene Simmons, Shauna Sand and Adrianne Curry. He appeared on several television shows and became one of the first people to perform plastic surgery on television in 1995.

A representative for Janice Dickinson released a statement about the death of Ryan. She said “Janice is deeply, deeply anguished! She is stunned and wants the world to know what a genius Dr. Ryan was.”

Ryan was traveling with his pet dog at the time of the crash; the dog was found seriously injured in the ocean and was transported to a local veterinarian. Dr. Ryan was pronounced dead at the scene.

Monday, January 25, 2010

Sales of previously owned homes in the US fell at the fastest rate ever recorded last December, according to data from the National Association of Realtors (NAR).

According to the association, existing home sales fell 16.7% last month, to an annual rate of 5.45 million, the largest crash since 1968. The figure was less than the 5.90 million units, or an eleven percent drop, predicted by most analysts.

Sales of homes went up for the entire of 2009 to 5.156 million units, or 4.9% for the year, and prices dropped from 2008 by 12.4%.

NAR chief economist Lawrence Yun described the figures as being “probably the largest annual drop since the Great Depression”. He said that “the market is going through a period of swings driven by the tax credit. We’re likely to have another surge in the spring. Job creation is the key to a continued recovery in the second half of the year.”

Pierre Ellis, a senior economist for Decision Economics in New York, commented on the figures, saying: “The drop in home sales is the payback for the acceleration of sales that occurred with the original first-time home buyers tax credit. […] There is an issue as to whether the decline represents a fundamental weakening.”

“The housing market continues to face significant headwinds, including high unemployment, record delinquencies and foreclosures, the specter of rising mortgage rates as the Fed’s [mortgage-backed securities] purchase programs comes to a close in late March, and tight credit,” Omair Sharif, an economist for RBS Securities, noted.

“Still, the resale market showed resilience in the second half of 2009, and the expansion and extension of the tax credit to April 30 could boost purchases during the spring selling season,” he said.

“We’ll see a pickup in existing home sales in the next couple of months as people take advantage of the tax-credit extension”, economist Adam York of Wells Fargo Securities LLC in Charlotte, North Carolina claimed. He fore-casted a pace of 5.4 million. He said that there were unlikely to be buyers of homes, despite the fact that the U.S. was “past the bottom.”

All four regions of the country saw a decline in sales. In the Northeast, sales fell 19.5 percent, in the Midwest, they plunged 25.8 percent. The South, the country’s largest region, saw a 16.3% decline, while in the West, sales waned by 4.8%.

US stocks fell slightly after the announcement, but went back up later in the day.