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.

Friday, August 19, 2005

An explosion from an underground utility chamber in downtown San Francisco severely injured a woman and shattered a window at a Ralph Lauren clothing store shortly after 10:00 a.m. Pacific time Friday. According to a caller to KCBS radio, a woman was engulfed in flames after the explosion triggered a fire in the store. The fire was quickly put out.

A bomb squad is currently investigating the explosion, and the cause has yet to be determined. One official said the explosion may have been caused by an electrical transformer. A witness described a fireball coming out of the side of the building

Pacific Gas & Electric Co. company spokesman Paul Moreno has stated that “there was no indication of a gas leak.” Moreno also described the aftermath of the blast. “The explosion did displace manhole covers — two round steel ones — and it also displaced a concrete cover as well,” Moreno said.

Some accounts have described a rift in the sidewalk caused by the explosion below.

Construction worker Tom Demartini, who was sitting in his truck outside the Ralph Lauren store, stated he saw the sidewalk rise up six or seven inches. “It sounded like a big poof, then there was a lot of smoke,” Demartini said. “One woman looked like she was badly burned.”

The burned woman was taken to the emergency room at St. Francis Hospital. Hospital spokeswoman Linda Gillespie had no immediate comment on her condition. Her name was not released.

Workers in a nearby office building described how the blast shook their buildings and that they thought it was an earthquake. According to one woman, the elevator in her building stopped.

Scores of police have evacuated buildings several blocks around the explosion. Kearny street between Sutter and Market has been closed to both vehicles and pedestrians.

Thursday, November 8, 2007

What you are about to read is an American life as lived by renowned author Edmund White. His life has been a crossroads, the fulcrum of high-brow Classicism and low-brow Brett Easton Ellisism. It is not for the faint. He has been the toast of the literary elite in New York, London and Paris, befriending artistic luminaries such as Salman Rushdie and Sir Ian McKellen while writing about a family where he was jealous his sister was having sex with his father as he fought off his mother’s amorous pursuit.

The fact is, Edmund White exists. His life exists. To the casual reader, they may find it disquieting that someone like his father existed in 1950’s America and that White’s work is the progeny of his intimate effort to understand his own experience.

Wikinews reporter David Shankbone understood that an interview with Edmund White, who is professor of creative writing at Princeton University, who wrote the seminal biography of Jean Genet, and who no longer can keep track of how many sex partners he has encountered, meant nothing would be off limits. Nothing was. Late in the interview they were joined by his partner Michael Caroll, who discussed White’s enduring feud with influential writer and activist Larry Kramer.

Thursday, June 11, 2009

Militants in Pakistan launched a truck bomb attack on the Peshawar Pearl Continental hotel, killing 18 and wounding at least 55. Among the dead were two foreign United Nations officials working for the World Food Programme.

According to the BBC, Fidayeen-e-Islam, a relatively obscure Pakistani militant group, claimed responsibility for the blast. The attack follows a threat from the Taliban made on May 27, warning of “major attacks” in Pakistan.

The bombing occurred despite the property being heavily guarded and secure. The militants gained entrance by overcoming the guards with gunfire, and forcing a bomb-laden truck, containing at least 500 kilograms of explosives, through the gates. Police official Liaqat Ali told the Associated Press that the militants “drove the vehicle inside the hotel gates and blew it up on reaching close to the hotel building.”

The bomb caused a 15-foot wide crater, and brought down the west wing of the hotel. An injured guest, Jawad Chaudhry, said, “The floor under my feet shook. I thought the roof was falling on me. I ran out. I saw everybody running in panic. There was blood and pieces of glass everywhere.”

The hotel is regularly used by businessmen and diplomats, and is located in a secure area of the city. Neighbours include the Peshawar High Court, Provincial Assembly and the official home of the Commander of the Frontier Corps. The perceived security of the neighbourhood makes it a candidate for the location of a planned United States consulate.