Sunglint on Titan

In early July, sunlight glimmers from a northern lake on Saturn's moon Titan

A month before the autumnal equinox heralded the advent of fall here in Earth’s northern hemisphere, Saturn’s moon Titan passed through its own vernal equinox, signaling the arrival of spring on its frigid surface. It was an event which planetary scientists had awaited since the interplanetary probe Cassini first entered Saturn orbit five years before.

The northern hemisphere of Titan, where most of the moon’s methane lakes are situated, has been locked in winter, its thick atmosphere enveloping the icy surface. Until now. As the angle of the sun’s rays arced more directly through the clouded skies of Titan’s northern climes in early July, sunlight glimmered from the shore of the Kraken Sea – a basin filled with hydrocarbons, larger than Earth’s largest lake, the Caspian Sea – and was captured by Cassini..

Aside from confirming our understanding of Titan’s surface lakes, this amazing image conveys the paradoxical reality of Titan, so radically different and yet so strangely similar to Earth.

For more, see NASA’s A Flash of Light from Titan.

Published in: on December 20, 2009 at 2:06 pm  Comments (2)  

Life On Icy Moons?

Jupiter's Moon Europa

“I think pretty much everyone can agree that finding life anywhere else in the solar system would be the scientific discovery of the millennium.”

In a presentation to the American Geophysical Union on December 15, Professor Francis Nimmo of the University of California at Santa Cruz discussed the habitability and prospects for finding life on the icy moons of Jupiter and Saturn, in particular on Europa and Enceladus. For a quick synopsis of his remarks, see Icy Moons of Saturn and Jupiter May Have Conditions Needed for Life in Science Daily:

“Enceladus is so small and its ice so thin that scientists expect its oceans to freeze periodically, making habitability less likely, Nimmo said. Europa, however, is the perfect size to heat its oceans efficiently. It is larger than Enceladus but smaller than moons such as Ganymede, which has thick ice surrounding its core and blocking communication with the exterior. If liquid water exists on Ganymede, it may be trapped between layers of ice that separate it from both the core and the surface.

“The core and the surface of these moons are both potential sources of the chemical building blocks needed for life. Solar radiation and comet impacts leave a chemical film on the surfaces. To sustain living organisms, these chemicals would have to migrate to the subsurface oceans, and this can occur periodically around ice fissures on moons with relatively thin ice shells like Europa and Enceladus. Organic molecules and minerals may also stream out of their cores, Nimmo said. These nutrients could support communities like those seen around hydrothermal vents on Earth.”

For further details, see the original UC Santa Cruz press release, and a related UCSC press release on the mechanism of Enceladus’ plumes, Frictional Heating Explains Plumes On Saturn’s Moon Enceladus, from May 2007.

Saturn's Moon Enceladus South Pole (NASA Cassini-Huygens)

Enceladus Surface (NASA -- Cassini)

Published in: on December 18, 2009 at 10:58 pm  Comments (1)  

Imagine A City With No Bookstore

Imagine a city nearly half the size of the Wichita metropolitan area without a single bookstore.

The Laredo Public Library serves 400,000 visitors annually, and the city library system is planning to open two new branches. But according to the Associated Press, Laredo will soon be the largest city in the United States without a bookstore.

If the local B. Dalton closes as planned next month, the nearest bookstore will be 150 miles away in San Antonio. And this in Webb County, Texas, where nearly half the population “lacks basic literacy skills, according to the National Center for Education Statistics.”

Imagine.

Published in: on December 18, 2009 at 5:42 pm  Leave a Comment  

Yellowstone Supervolcano, 3

Yellowstone Hot Spot Map (U of Utah)

For more than a dozen different very interesting (but perhaps challenging) technical studies of the Yellowstone Mantle Plume and related phenomena, see Yellowstone Plume, Hotspot, and Wasatch Front Earthquake Research from the University of Utah’s Seismology and Active Tectonics Research Group You’ll find much collateral information there as well, including a movie of the tilted plume, maps, charts, and more.

Published in: on December 18, 2009 at 4:29 pm  Comments (1)  

Yellowstone Supervolcano, 2

Geyser Erupts in Yellowstone (edupics.com)

Yesterday, in Yellowstone Supervolcano, we mentioned the latest geological evidence concerning the enormous mantle plume that underlies the Yellowstone supervolcano. In Yellowstone’s Plumbing Exposed e! Science News provides more detail. It’s a fascinating read.

Yellowstone Mantle Plume (University of Utah)

Published in: on December 18, 2009 at 3:49 pm  Comments (3)  

Merry Christmas vs. Happy Holidays

The Pew Research Center for the People and the Press reports that “when given the option of hearing ‘Merry Christmas’ or a less religious greeting — like ‘Happy Holidays’ — in stores and businesses, Americans choose Merry Christmas by a 60%-to-23% margin. When specifically given ‘doesn’t matter’ as an option, however, a 45%-plurality have no preference for how they are greeted during the holiday season — 42% want Merry Christmas and 12% prefer the less religious greeting. Seniors (those ages 65 and older) strongly prefer Merry Christmas (64%) but the youngest Americans (18-29) are much more likely to say it does not matter (59%). Politically, Republicans are the biggest advocates of Merry Christmas (62%), while nearly half (49%) of Democrats and a small majority (52%) of independents are unconcerned by stores’ choice of holiday greetings.”

For more details on the survey and for related survey results on Christmas displays on public property, holiday concerns and other matters see this post from the Pew Center.

Published in: on December 18, 2009 at 3:21 pm  Leave a Comment  

California Library Closes

“Libraries raised me. I don’t believe in colleges and universities. I believe in libraries, because most students don’t have any money. When I graduated from high school, it was during the Depression and we had no money. I couldn’t go to college, so I went to the library three days a week for 10 years.”

– Ray Bradbury

Despite an appearance at a fundraiser by writer Ray Bradbury last June, and efforts by the San Buenaventura Friends of the Library, the H. P. Wright Library in Ventura, California closed on the last day of November – a victim of the steep recession, California budget woes, and failure to pass a critical bond issue.

Published in: on December 18, 2009 at 11:46 am  Leave a Comment  

Holiday Mail

According to the US Postal Service 16.6 billion cards, letters and packages will be delivered between December 1 and Christmas Day this year. They anticipated that December 14th would be the busiest mailing day, and that yesterday, December 16th, would be their busiest delivery day.

Published in: on December 17, 2009 at 7:40 pm  Leave a Comment  

Yellowstone Supervolcano

Yellowstone Relief Map (University of Utah, Robert B Smith)

Three times during the past two million years, the Yellowstone supervolcano has erupted, leveling mountains and covering half of North America with ash.

As described in the notice for a lecture to be delivered earlier this year by the University of Utah’s Robert B. Smith — The Yellowstone Supervolcano: Past, Present and Future — “the energy responsible for creating these geologic features comes from a 50-mile-wide ‘hotspot’ or ‘mantle plume’ of molten rock that originates at least 400 miles below the Idaho-Montana border, and then angles eastward and rises until it is only 30 miles beneath Yellowstone. There, the plume hits cooler rock and spreads out to a width of 300 miles.

“The buoyancy of the hot plume lifts Yellowstone and the surrounding region into a 500-mile-wide ‘topographic swell’ that pushes the ground well above 7,000 feet elevation, or about 1,600 feet higher than it would be without the underground plume.

“The volcanic plume also fuels a shallow ‘magma chamber’ of hot and partly molten rock that extends from about five miles beneath Yellowstone to a depth of at least 10 miles.”

This immense powerhouse is the source for all the amazing wonders which attract hundreds of thousands of visitors to the nation’s first National Park. “The crustal magma body continues to fuel Yellowstone’s geysers and power a restless caldera, which, like others on Earth, huffs upward and puffs downward for millennia without erupting — often by many feet over the decades. The caldera floor rose 40 inches during 1923-1984, fell 8 inches during 1985-1995, rose a few inches maximum during 1995-2000, mostly sank about an inch during 2000-2003, then mostly rose more than 3 inches since mid-2004 — three times faster than its historic rate of uplift.

“Movement of magma and hydrothermal fluids cause these ups and downs. Studies have revealed Yellowstone’s hydrothermal systems release 100 watts per 36 square feet — in other words, a square of ground measuring 6 feet on a side emits enough heat to power a 100 watt light bulb. That’s more than 20,000 times the heat emitted by the average rock in North America.

“During late December 2008 and early January 2009, Yellowstone experienced its second-largest earthquake swarm in recorded history, and it was well-documented by the University of Utah real-time seismic network. The sequence consisted of about 1,000 earthquakes, including a dozen quakes of magnitude 3.0 or higher, and one as large as 3.9 on the Richter scale.”

Now, a new study of the Yellowstone supervolcano has determined that the magma chamber is 20 percent larger than previously believed, and verified that it reaches deep beneath the earth’s crust into the mantle.

The three historical eruptions, which took place 2.05 million years ago, 1.3 million years ago, and 642,000 years ago, were respectively 2,500, 280, and 1,000 times larger than the eruption of Mount Saint Helens in 1980.

Yellowstone Plume (University of Utah)

Published in: on December 17, 2009 at 6:14 pm  Comments (2)  

Kansas Population: Anticipating the Census

As we approach a new national census in the coming year, what is the best current estimate of where Kansas and the Wichita Metropolitan Statistical Area stand?

According to the most recent population estimates released by the Census Bureau, Kansas has experienced a 4.2 percent increase in population from the year 2000 through July 1, 2008, to an estimated population of 2,802,134. This represents an increase of 113,318 Kansans.

Kansas would thus rank 33rd among the states in population at present (versus 32nd in 2000), and 34th in percent change.

The Midwest as whole averaged a 3.4 percent increase, slightly below that of Kansas, during the same time period.

The Wichita Metropolitan Statistical Area, meanwhile, grew by an estimated 32,545 to 603,716 as of July 1, 2008, ranking 84th among all metro areas (versus 80th in 2000).

Published in: on December 17, 2009 at 5:20 pm  Comments (1)  

Six Armies in Tennessee

Steven E Woodworth’s Six Armies in Tennessee, in print now for just over a decade, is a well-written, highly readable and deftly paced short history of the Civil War campaign for Central and Eastern Tennessee in 1863.

Beginning with the aftermath of the battle of Stone’s River, continuing through the battle of Chickamauga and the battles for Chattanooga, and concluding just after the failed siege of Knoxville, Six Armies in Tennessee explores a campaign, overshadowed in the popular imagination by the Union victories at Gettysburg and Vicksburg that same year, but no less decisive in its results. Chickamauga, which took place precisely one year after Antietam, was the bloodiest two-day engagement of the entire war. (Antietam witnerssed the single bloodiest day for American troops in all our history.)

Woodworth’s treatment of the oft-disparaged Confederate commander General Braxton Bragg is an eminently fair and balanced one, far more sympathetic than most. Bragg’s greatest failing was not so much strategic acumen or its lack as it was a plague of truly dismal subordinates who failed him repeatedly, and whom he could not or would not motivate or break.

Similarly, Woodworth’s analysis of the merits of the successive Union commanders, Major Generals William S. Rosecrans and Ulysses S. Grant, is equally perceptive and balanced.

At just under 220 pages, Six Armies in Tennessee is brief, but not too brief, graced with good footnotes, an adequate index and a short but useful Bibliographical Essay.

I heartily recommend this history to anyone curious about this vitally important but too often ignored campaign.

Confederate Commander throughout the campaign, Braxton Bragg

Published in: on December 17, 2009 at 3:44 pm  Leave a Comment  

Phobos and Deimos

Phobos & Deimos Aligned (Mars Express Orbiter - ESA)

In early November the European Space Agency’s Mars Express Orbiter captured this amazing image of Mars’ two moons, Phobos and Deimos in alignment. On the ESA website there is a great video of successive images captured as the Mars Express approached the position depicted above. See “Pioneering Images of Both Martian Moons” for the video and more.

Here’s a closeup of the smaller moon, Deimos:

And here’s an image of the larger moon, Phobos:

Published in: on December 17, 2009 at 12:21 pm  Comments (2)  
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