ASTRONOMY NEWS AND EVENTS
Mars Puzzle May Be Solved
Planetary scientists have wondered for years about an apparent contradiction on Mars. Abundant evidence points to an early warm, wet climate on the red planet, but there's no sign of the widespread carbonate rocks, such as limestone, that should have formed in such a climate.
A new study by MIT's Maria T. Zuber and Itay Halevy and Daniel P. Schrag of Harvard University provides a possible answer to the mystery. In addition to being warmed by a greenhouse effect caused by carbon dioxide in the atmosphere, as on Earth, the early Mars may have had the greenhouse gas sulfur dioxide in its atmosphere. That would have interfered with the formation of carbonates, explaining their absence today.
It would also explain the discovery by the twin Mars rovers, Spirit and Opportunity, of sulfur-rich minerals that apparently formed in bodies of water in that early Martian environment. And it may provide clues about the Earth's history as well.
The challenge was to interpret the planet's history, based on the data gathered by the Mars rovers--and especially Opportunity's discovery of sulfate minerals--from just tiny fractions of the surface, says Zuber, who is head of MIT's Department of Earth, Atmospheric and Planetary Sciences and the E.A. Griswold Professor of Geophysics. "How do you take very detailed measurements of chemical composition at one tiny place on Mars," she says, "and put it into the context of the broad evolution of the planet?" The breakthrough, she said, was when she and her colleagues realized "we'd been after the wrong molecule."
After several years of exploring the role of carbon dioxide and the carbon cycle, she said, they realized "maybe the key is sulfur dioxide, not carbon dioxide."
It was Opportunity's discovery of the mineral jarosite, which only forms in highly acidic water, that set them thinking about how that acidic environment could have come about. Sulfur provided the answer.
The new analysis suggests that on Mars, sulfur went through a whole cycle through the atmosphere, bodies of water on the surface, and burial in the soil and crust, comparable to the well-known carbon cycle on Earth. Through most of Earth's history, carbon dioxide has been released in volcanic eruptions, and then absorbed into seawater, where it fosters the formation of calcium carbonate (limestone), which gets buried in ocean sediments.
Much evidence suggests Mars may once have had an ocean that covered about a third of the planet, in its northern hemisphere. Sulfur dioxide dissolves easily in water, so after being spewed into the atmosphere by the giant volcanoes of Mars' Tharsis bulge, much of it would have ended up in the water, where it inhibited the formation of carbonate minerals but led to the formation of silicates and sulfites, such as calcium sulfite.
These minerals degrade relatively rapidly, so they would not be expected on the surface of Mars today. But they also allow formation of clays, which have been found on Mars, and which added to the puzzle since clays are usually associated with the same conditions that produce carbonates.
The new picture of a sulfur cycle helps to solve another mystery, which is how early Mars could have been warm enough to sustain liquid water on its surface. A carbon dioxide atmosphere produces some greenhouse warming, but sulfur dioxide is a much more powerful greenhouse gas. Just 10 parts per million of sulfur dioxide in the mostly carbon dioxide air would double the amount of warming and make it easier for liquid water to be stable.
The analysis may also tell us something about our own planet's past. The early Earth's environment could well have been similar to that on Mars, but most traces of that era have been erased by Earth's very dynamic climate and tectonics. "This might have been a phase that Earth went through" in its early years, Zuber says. "It's fascinating to think about whether this process may have played a role" in the evolution of the early Earth.
The team's detailed analysis appeared in the December 21 issue of Science. To learn more about the latest discoveries on Mars, visit the Mars Exploration Rover Mission home page: http://marsrover.nasa.gov/home/index.html
The Search for ET Just Got Kicked Up
The longest-running search for extra terrestrial radio signals is getting a burst of new data from an upgraded telescope. The result is dramatically improved search capabilities, but the full benefits will be realized only with public participation. Astronomers are calling for new volunteers for SETI@home, a project in which ordinary citizens donate unused time on their computers to let the machines help comb through the search data.
“The next generation SETI@home is 500 times more powerful than anything anyone has done before,” said project chief scientist Dan Werthimer. “That means we are 500 times more likely to find” alien life—if enough new volunteers join. Even if not, the upgrades still promise an improvement of at least about 100-fold, he said.
Since it launched eight years ago, the University of California, Berkeley-based SETI@home has signed up more than 5 million interested volunteers, according to project scientists. It boasts the largest community of dedicated users of any Internet computing project, they said: 170,000 devotees on 320,000 computers. This number of computers should rise by an additional million to handle the expanded data flow, Werthimer said.
The increased amount of data is a result of new and more sensitive receivers and other improvements to the world’s largest radio telescope in Arecibo, Puerto Rico, said project leaders. The software used for the job, they added, has been upgraded to deal with the surge of information.
According to project scientist Eric Korpela, the new data amounts to 300 gigabytes per day; on a yearly basis that adds up to the amount of data stored in the U.S. Library of Congress. “That’s why we need all the volunteers,” he said. “Everyone has a chance to be part of the largest public-participation science project in history.”
The 1,000-foot wide Arecibo dish, which fills a valley in Puerto Rico, is part of the National Astronomy and Ionosphere Center operated by Cornell University in Ithaca, N.Y. Since 1992, Werthimer and his team have used radio observations at Arecibo to record signals from space and analyze them for patterns that could indicate they were transmitted by a civilization.
When the team’s incoming data overwhelmed its ability to analyze it, the scientists conceived a “distributed computing” project to harness many computers into one big supercomputer to do the analysis. Since SETI@home was launched, other distributed computing projects have arisen, from folding@home to predict the structures of organic molecules, to the newly-launched cosmology@home to model possible universes. Most share the SETI@home platform.
“Until now, there has been enough computing power to go around,” Werthimer said. What largely triggered the new flow of data was the addition of seven new receivers at Arecibo, which let the telescope record signals from seven regions of the sky simultaneously instead of one, he added.
“The multiple receivers help us weed out interference better” and reduce the chance of mistaking earthly signals from alien ones, he said. No telltale signals from an intelligent civilization have yet been identified.
“Earthlings are just getting started looking at the frequencies in the sky; we’re looking only at the cosmically brightest sources, hoping we are scanning the right radio channels,” Werthimer said. “The good news is, we’re entering an era when we will be able to scan billions of channels. Arecibo is now optimized for this kind of search, so if there are signals out there, we or our volunteers will find them.”
SETI stands for Search for Extraterrestrial Intelligence. To learn more, check out the home page of SETI@home at the University of California at Berkeley: http://setiathome.berkeley.edu/
Mars Impact Possibility Goes Up, Then Down
Two weeks back, we reported on the possibility of an asteroid impact with the planet Mars on January 30. The body is designated asteroid 2007 WD5, discovered on November 20, 2007 by the NASA-funded Catalina Sky Survey using a 1.5-meter telescope on Mt. Lemmon, near Tucson. At the time of that reporting, with a limited number of observations, astronomer estimated a 1.3%, or 1-in-75, chance of the impact.
About a week later, astronomers reported that additional observations had caused the estimate to increase to 3.9%, or a 1-in-25, chance of the impact.
Further observations through January 2 have reduced by a factor of 3 the range of possible paths of the asteroid past Mars. The most likely path has moved a little farther away from the planet, causing the Mars impact probability to decrease slightly to 3.6% (about a 1-in-28 chance). The latest observations were made using the 2.4 meter telescope at New Mexico Tech's Magdalena Ridge Observatory and reported by astronomer Bill Ryan. Astronomers suggest that as additional observations further shrink the uncertainty region of this asteroid, the region will no longer intersect Mars and the impact probability will quickly drop to zero.
To learn more, visit the home page of the NASA/JPL Near-Earth Object Program: http://neo.jpl.nasa.gov
Youngest Exoplanet Yet Discovered
The time required for planetary formation has long been a matter of debate. The currently popular theory says that planets are created several million years after star formation, from the star's leftover disc of gas and dusty debris. Now, astronomers observing a young star 180 light years from Earth have found evidence that stellar birth can lead to the formation of a planet within a few millions of years, just a blink on the cosmic timescale.
Astronomers estimate that it has a mass 3,115 times that of Earth and 9.8 times that of Jupiter.
Previously the youngest planet to have been identified was an estimated 100 million years old. In contrast, Earth is estimated to be 4.5 billion years old.
The new planet orbits an infant star, called TW Hydrae (TW Hya), which is thought to have formed between eight and ten million years ago.
The planet would have formed shortly after the birth of the star and it is possible that other planets are forming within the disc. The star is 180 million light years from Earth.
The new planet orbits 3.7 million miles from its parent star – compared with the 93 million miles between Earth and the sun – and takes only 3.56 days to complete an orbit around TW Hya.
The discovery of the planet is expected to provide insights into the mechanisms.
The researchers demonstrated that the new planet, TW Hya b, formed within the first ten million years of the star system’s formation, before stellar winds and radiation could dissipate the clouds.
The process of formation of the TW Hya system is continuing and is thought to be nearly complete. There is a gap of 5.6 million miles between the star and the inside edge of the disc of clouds surrounding it.
The planet lies between the disc and the star and it was the absence of gas or dust in the gap where it orbits that helped to alert astronomers. Vast discs of dust and gas are thought to form stars and planets because microscopic specks of matter bump into each other to create lumps that eventually become big enough to form cores.
Researchers from the Max Planck Institute for Astronomy, in Germany, reported their discovery in the January 3 issue of the British journal Nature. They said: “There is a general consensus that planets form within discs of dust and gas around newly born stars. Details of their formation process, however, are a matter of debate. The timescale of planet formation remains unclear, so the detection of planets around young stars with protoplanetary discs is potentially of great interest. Hitherto, no such planet has been found.”
An alternative theory is that gravitational anomalies within the disc of dust and gas cause giant planets to form.
Exoplanets were first discovered in 1995. To date, 270 of have been spotted, according to the Extrasolar Planets Encyclopaedia. Virtually all of the discoveries have been made indirectly, mainly by a "wobble" in light, seen from Earth, when the planet swings around its star.
To learn more about extrasolar planets, visit the Extrasolar Planets Encyclopaedia: http://exoplanet.eu/
Learning From Grains of Comet Dust
Four years ago, NASA's Stardust spacecraft chased down a Comet Wild-2 (pronounced “Vilt-two”) and collected grains of dust blowing off its nucleus. When the Stardust spacecraft returned, comet dust was shipped to scientists all over the world, including University of Minnesota physics professor Bob Pepin. After testing helium and neon trapped in the dust specks, Pepin and his colleagues report that while the comet formed in the icy fringes of the solar system, the dust appears to have been born close to the infant sun and bombarded by intense radiation from these and other gases before being flung out beyond Neptune and trapped in the comet.
The finding opens the question of what was going on in the early life of the solar system to subject the dust grains to such intense radiation and then hurl them hundreds of millions of miles from their birthplace.
The studies of cometary dust are part of a larger effort to trace the history of our celestial neighborhood.
"We want to establish what the solar system looked like in the very early stages," said Pepin. "If we establish the starting conditions, we can tell what happened in between then and now." One early event was the birth of Earth's moon, about 50 million years after the solar system formed.
Also, the gases he studies have relevance even closer to home. "Because some scientists have proposed that comets have contributed these gases to the atmospheres of Earth, Venus and Mars, learning about them in comets would be fascinating," he said.
Comet Wild-2 is thought to have originated in the Kuiper Belt, a comet-rich region stretching from just inside the orbit of Neptune to well beyond Pluto. As it grew in this roughly -360 F region, it incorporated grains of dust and ambient gas.
The comet received a visit from the Stardust spacecraft in early January 2004, two years after its launch. Veering as close as 149 miles to the comet nucleus, Stardust used a spongy, ultralight glass-fiber material called aerogel to trap the dust. At the moment of encounter, the spacecraft exposed a sheet of aerogel -- supported by a framework -- to the stream of particles blowing off the nucleus.
"It looked like a tennis racket," said Pepin. "It was exposed for approximately 20 minutes."
The aerogel trapped aggregates of fine particles that hit at 13,000 miles per hour and split on impact. The collisions left drumstick-shaped trails pointing inward from the surface of the aerogel.
After the collection, the spacecraft headed home and parachuted its payload safely back to Earth in January 2006. A few months later, Pepin received three sub-samples of particles and colleagues at Nancy University, France, received two others, all from the same particle "hit."
Their task was to analyze gases locked in tiny dust grains about a quarter of a billionth of a gram in weight. As a first step, the researchers heated the grains to about 1,400 degrees C., liberating gases imprisoned for eons.
"The particles probably came from the first million years or even less, of the solar system's existence," Pepin said. That would be close to 4.6 billion years ago. If our middle-aged sun were 50 years old, then the particles were born in the first four days of its life.
The research appears in the Jan. 4 issue of the journal Science. To learn more about the Stardust mission, visit the mission home page: http://stardust.jpl.nasa.gov/
No One Expected a Vatican Eviction
Pope Benedict XVI has instructed the Vatican's Jesuit astronomers to remove themselves and their instruments from the papal summer palace, Castel Gandolfo, and relocate to an unused convent. The change was apparently necessary in order to provide more space for visiting diplomats.
Many observers view the change as a negative move in the Church's relationship with science, which dates back to the time of Galileo and earlier. Some accuse Benedict of trying to turn the clock back on his predecessor's embrace of science.
Others suggest the observatory’s main problem is that it’s largely run by Jesuits, one of the groups having a stormy relationship with the Holy See. After their use as the Pope's shock troops during the counter-reformation, the order was suppressed in the 18th century, before being restored in the 19th century. Nevertheless, some apparently feel that the Jesuits are too clever and have a tendency toward liberal thinking.
In spite of the controversy over the move, the observatory's director, Father Jose Funes, insists "It is not a downgrading of science in the Vatican."
Earlier this year, Benedict welcomed attendees to the observatory’s summer school with the message: "The Vatican Observatory has sought to demonstrate the Church's desire to embrace, encourage, and promote scientific study, on the basis of her conviction that 'faith and reason are like two wings on which the human spirit rises to the contemplation of truth'."
To learn more about the Vatican Observatory, visit their Website, hosted by Steward Observatory at the University of Arizona, Tucson: http://clavius.as.arizona.edu/vo/R1024/VO.html
Solar Cycle 24 Has Begun
Solar physicists have been waiting for the appearance of a reversed-polarity sunspot to signal the start of the next solar cycle, and the wait is finally over. On January 4, a magnetically reversed sunspot emerged at solar latitude 30 degrees N.
Many forecasters think Solar Cycle 24 will be big and intense. Starting slow and peaking in 2011 or 2012, the cycle to come could have significant impacts on telecommunications, air traffic, power grids and GPS systems, as well as creating some spectacular auroras.
For more on the sun, check out these links:
The Solar and Heliospheric Observatory (SOHO): http://sohowww.nascom.nasa.gov/
Mercury and MESSENGER, Part 1 of 2
On January 14, the planet Mercury will be visited by the second robotic probe from Earth. The mission is called MESSENGER, meaning MErcury Surface, Space ENvironment, GEochemistry, and Ranging. While the first visitor, Mariner 10, only made three passes (or fly-bys), MESSENGER will gradually settle into orbit around Mercury in 2011 and study the planet closely for one full Earth year. Prior to this, MESSENGER will perform three flybys of Mercury. The first will be January 14, the second October 6 and the third September 29, 2009. With first flyby coming up, here is a two-part overview of the swift planet Mercury.
Mercury is the planet in our solar system nearest the sun. It has a diameter of 3,032 miles (4,879 kilometers), about two-fifths that of Earth. Mercury orbits the sun at an average distance of about 36 million miles (58 million kilometers), compared with about 93 million miles (150 million kilometers) for Earth.
Because of its size and nearness to the sun, Mercury is often hard to see from the Earth without a telescope. At certain times of the year, Mercury can be seen low in the western sky just after sunset. At other times, it can be seen low in the eastern sky just before sunrise.
Orbit and Distance
Mercury travels around the sun in an elliptical (oval-shaped) orbit. The planet is about 28,580,000 miles (46,000,000 kilometers) from the sun at its closest point, and about 43,380,000 miles (69,820,000 kilometers) from the sun at its farthest point. Mercury is about 48,000,000 miles (77,300,000 kilometers) from Earth at its closest approach.
Mercury moves around the sun faster than any other planet. The ancient Romans named it Mercury in honor of the swift messenger of their gods. Mercury travels about 30 miles (48 kilometers) per second, and goes around the sun once every 88 Earth days, or about 4.1 times in one Earth year.
Until the mid-1960's, astronomers thought that Mercury rotated on its axis once every 88 Earth days, the same time the planet takes to go around the sun. This implied that one side of Mercury always faced the sun, and the other side was always dark. However, radar studies conducted in 1965 showed that the planet actually rotates once in 58.65 Earth days -- a rotation slower than any other solar system planet except Venus. This is a siderial day, or the time required for all of the stars in the Mercurian sky to move around exactly once.
In contrast, the planet's slow rotation and rapid orbit causes Mercury's solar day, or the interval between one sunrise and the next, to lasts 176 Earth days.
When viewed over time through an optical telescope, Mercury appears to change in shape and size. The changes in shape are called phases, and resemble those of the moon. They result from different parts of Mercury's sunlit side being visible from the Earth at different times. The changes in size correspond to Mercury's varying distance from Earth as Mercury and the Earth travel around the sun. Mercury can be seen on the far side of the sun about every 116 days. At this point, almost all its sunlit area is visible from the Earth. It looks like a bright, round spot (or gibbous) with almost no visible marks. As Mercury moves behind the sun and then toward the Earth, less and less of its sunlit area can be seen (or Mercury wains). After about 36 days, only half its surface is visible. After another 22 days, it nears the same side of the sun as the Earth, and only a thin sunlit area (or crescent) is visible. The amount of sunlit area that can be seen increases gradually (or waxes) after Mercury passes in front of the sun and begins moving away from the Earth.
When Mercury is on the same side of the sun as the Earth is, its dark side faces the Earth. The planet is usually not visible at this point because Mercury and the Earth orbit the sun at different angles. As a result, Mercury does not always pass directly between the Earth and the sun. Sometimes Mercury is directly between the Earth and the sun. When this occurs, every 3 to 13 years, the planet is in transit and can be seen as a black spot against the sun.
Next time: Mercury and MESSENGER, Part 2 of 2
MESSENGER, the official site for the MErcury Surface, Space ENvironment, GEochemistry, and Ranging mission. Retrieved January 2, 2008.
Zuber, Maria T. "Mercury." World Book Online Reference Center. 2004. World Book, Inc. Retrieved January 2, 2008.
Planets: Mercury. In NASA Solar System Exploration, Last updated November 5, 2007. Retrieved January 2, 2008, from the NASA Solar System Exploration website, maintained by NASA's Jet Propulsion Laboratory:
THE SKY THIS WEEK
Jan 5 - The planet Venus is 7° north of the moon
Jan 5 - The star Antares is 0.5° north of the moon, occultation. An occultation occurs when one object passes in front of a smaller one, temporarily obscuring all or part of the background object from view.
Jan 6 - The planet Venus is 6° north of the star Antares
Jan 8, 6:37 A.M. (11:37 UTC) - New Moon
Jan 10 - The planet Neptune is 0.4° north of the moon, occultation. An occultation occurs when one object passes in front of a smaller one, temporarily obscuring all or part of the background object from view.
Jan 12 - The planet Uranus is 3° south of the moon
Jan 14 - MESSENGER performs first Mercury Flyby
Jan 14 - Ulysses reaches maximum north solar latitude (79.8 Degrees)
THIS WEEK IN HISTORY
Jan 6, 1998 - Launch of Lunar Prospector (Moon Orbiter), 10th anniversary
Jan 6, 1968 - Launch of Surveyor 7 (US Moon Lander), 40th anniversary
Jan 6, 1985 - La Criolla Meteorite Fall (Hit House), with type L6 Chondrite meteorites, in La Criolla, Argentina. The strewnfield was 10 km long.
Jan 7, 1610 - Discovery of Jupiter moons Io, Europa and Callisto by Italian astronomer, physicist and mathematician Galileo Galilei (1564 - 1642)
Jan 7, 1985 - Launch of Sakigake (Japan Comet Halley Mission)
Jan 8, 1587 - Birthday of Dutch astronomer Johannes Fabricius (1587 - ca. 1615). Fabricius may have been the first observer of sunspots (1610/1611) and he was the first to publish sunspot observations.
Jan 8, 1868 - 140th Birthday of British astronomer Sir Frank Watson Dyson FRS (1868 - 1939). Dyson is remembered mainly for introducing time signals ("pips") from Greenwich, England, and for organizing expeditions to the 1919 solar eclipse, where Einstein's theory of general relativity was tested (the theory of the effect of gravity on light).
Jan 8, 1905 - Discovery of Asteroid 554 Peraga & Asteroid 556 Phyllis by astronomer Paul Götz
Jan 8, 1942 - Birthday of Stephen Hawking
Jan 8, 1973 - Launch of Luna 21 (USSR Moon Lander/Rover) 35th anniversary
Jan 9, 1986 - Discovery of Uranus moon Cressida by Voyager mission scientist Stephen P. Synnott
Jan 9, 1990 - Launch of STS-32 Columbia with the LDEF satellite
Jan 10, 1936 - Birthday of U.S. astronomer Robert Woodrow Wilson
Jan 10, 1969 - Launch of Venera 6 (Soviet Venus Lander)
Jan 11, 1610 - Discovery of Jupiter moon Ganymede by Italian astronomer, physicist and mathematician Galileo Galilei (1564 - 1642)
Jan 11, 1787 - Discovery of Uranus moons Titania and Oberon by German-British astronomer William Herschell (1738 – 1822)
Jan 12, 1820 - Birthday of the Royal Astronomical Society
Jan 12, 1907 - Birthday of Ukranian-born rocket designer and engineer Sergel Pavlovich Korolev (1907 – 1966), mastermind of the Soviet Union’s early success in the international space race.
John Henry Hopkins, Jr. (1820 - 1891) was the oldest of several children by John Henry Hopkins, a bishop in the Protestant Episcopal Church. Following his graduation from the General Theological Seminary, New York City, in 1850, Hopkins was ordained a deacon in the Protestant Episcopal Church. Later, in 1872, Hopkins was ordained a priest and eventually lead congregations in New York and Pennsylvania.
Hopkins wrote extensively on the church and on church music. In 1853, he founded the "Church Journal" and was its editor and proprietor until 1868.
In 1857, Hopkins assisted in the production of the General Theological Seminary's Christmas pageant by writing a song for the appearance of the magi, or wise men. The Bible tells us very little about the magi, but scholars of today suggest that they were likely part of a caste of Zoroastrian priests and sages from ancient Persia.
In his song, Hopkins described the magi based upon common inferences made by others of his day. They did not know their social station of the magi, but the great value of the gifts suggested that the magi were persons of great wealth and authority and possibly kings. Also, they did not know the number of magi, but tradition suggested there was one to bear each gift, and so there were three. Hopkins did not describe the magi as being from Persia, but rather used a common term of the day, stating they were from the Orient. This general term described the areas of the Middle East, Egypt and Arabian influenced North Africa.
Through the verses of the song, Hopkins presented the magi and explained the significance of their gifts to the Christ child. The result was a wonderful musical story on the birth, life, death, resurrection, and lordship of Jesus Christ. Though the song was first performed as part of the 1857 Christmas pageant, Hopkins did not publish it until 1863 in his collection, “Carols, Hymns and Song." The song is called "The Quest of the Magi," but it is more popularly known by its first line of text, "We Three Kings of Orient Are."
In addition to being sung at Christmas, it is also sung by many a Epiphany, 12 days after Christmas (December 12), when many recognize the arrival of the magi at the home of the young child Jesus.
We Three Kings of Orient Are
We three kings of Orient are;
Bearing gifts we traverse afar,
Field and fountain, moor and mountain,
Following yonder star.
O star of wonder, star of light,
Star with royal beauty bright,
Westward leading, still proceeding,
Guide us to thy perfect light.
Born a King on Bethlehem’s plain
Gold I bring to crown Him again,
King forever, ceasing never,
Over us all to reign.
Frankincense to offer have I;
Incense owns a Deity nigh;
Prayer and praising, voices raising,
Worshipping God on high.
Myrrh is mine, its bitter perfume
Breathes a life of gathering gloom;
Sorrowing, sighing, bleeding, dying,
Sealed in the stone cold tomb.
Glorious now behold Him arise;
King and God and sacrifice;
Sounds through the earth and skies.
We Three Kings - The Cyber Hymnal
Retrieved January 1, 2008
We Three Kings of Orient Are – Christmas Carols
Copyright © 2004 Carols.org
Retrieved January 1, 2008
Biography and hymns of John Henry Hopkins, Jr., 1820-1891, (Retrieved January 1, 2008) - http://www.cyberhymnal.org/bio/h/o/p/hopkins_jh.htm
John Henry Hopkins > Hall of North and South Americans > Museum of History
Retrieved January 1, 2008
We Three Kings of Orient Are - An Online Christmas Songbook
Edited by: Christopher R. Baker ©1999 - 2003
Retrieved January 1, 2008