Update: March 18, 2008

RINGS AND SNAKES

By Pam Eastlick for THE DEEP on line

Welcome to The Deep science and technology column where we cover topics from the deep sea to deep space and beyond.

Well, spring is here and the days are growing longer. But that means I'm not starting with my usual story about Antarctica because for the South Pole it's autumn and the beginning of the long and endless night. It's not so easy to do research in the dark and there probably won't be many more stories out of Antarctica for about six months or so. But you should expect a few more research tales from the North Pole before too long! So instead of traveling to the land of snow and ice; let's travel to the land of snow and ice . . . . but this land is MUCH farther away than Antarctica. We're headed for Saturn where the Cassini spacecraft has been making one marvelous discovery after another. Cassini has shown us a bizarre black and white moon with a 12-mile mountain range exactly at its equator (Iapetus) and the brightest moon in the solar system that's spraying what appears to be water loaded with organic chemicals from its south pole (Enceladus). Then there's Titan; the only moon in the solar system with a thick atmosphere. Look for an all-Saturn edition of The Deep column soon!

RINGS AND THINGS

But of course, the most prominent feature of Saturn is its rings and Cassini is unearthing answers and new questions about them too. We've known for a long time that Saturn's rings were made most of ice cubes. Yes, they're made mostly of water ice (with other ices and dust, sand grains & small rocks mixed in) and most of the particles are the size of ice cubes. Some are bigger and some are much smaller. Saturn's rings are very wide (around 100,000 miles) but they are only about a mile thick. There are big gaps in the rings and planetary researchers have discovered over the years that most of these gaps are caused by the gravitational effects of some of Saturn's many moons. Cassini has also verified that at least some of the material in Saturn's rings is coming from its moons. Enceladus is spraying material all the time and the black and white moon Iapetus seems to be covered by black material that has perhaps come from another moon. Now Cassini scientists have found evidence that Saturn may also be surrounded by undiscovered, nearly invisible partial rings. Gaps in the soup of very high energy particles near the orbits two newly discovered tiny moons may be the first indication of new rings for Saturn. The moons are Methone and Anthe. Methone, discovered by Cassini in 2004, is about 2 miles across (3 kilometers), while Anthe, discovered in Cassini images in 2007, is about a mile wide (2 kilometers). Both moons are located between the orbits of Saturn's moons Mimas and Enceladus. The fact that particles are missing is sensed by Cassini in the same way there are brief moments without rain falling on the windshield when driving under a bridge. These gaps in the flow of electrons showed that something wide was absorbing the charged particles. Although moons can absorb high energy particles, Methone and Anthe by themselves aren't big enough to cause the large breaks (600 to 1,900 miles across) in the rain of high energy electrons put out by Saturn and the Cassini scientists think Methone and Anthe may be shedding large quantities of invisible dust. Their measurements indicate that the two moons are losing dust from their surface, building up one or more arcs of material along their orbits. Each ring arc could be a few thousand kilometers wide and made mostly of large dust grains or dust clumps.

Meteoroid impacts on Methone and Anthe are the most likely cause of the release of this material from their surfaces. The same process is thought to have formed Jupiter's faint rings at the orbits of the moons Amalthea, Thebe, Metis and Adrastea. The same situation might be happening at Saturn. In fact, rings of similar origin have also recently been detected in Cassini images along the orbits of the Saturnian moons Janus, Epimetheus and Pallene. Bizarre moons and invisible rings. Saturn is a place of wonder indeed!

RESEARCHING THE BLUES

I did a story a couple of weeks ago about the Mayans and their incredible love of colors in their decorations. Researchers have recently discovered that the Rosalia temple (which is still buried inside a pyramid) was painted a brilliant red with bits of mica in the paint. The temple would have sparkled in the Sun in an amazing display or ancient bling. Now researchers think they've discovered the secret of yet another Mayan pigment; Maya Blue. Anthropologists from Wheaton College and The Field Museum in Chicago have discovered how the ancient Maya produced an unusual and widely studied blue pigment that was used in offerings, pottery, murals and other contexts across Mesoamerica from about A.D. 300 to 1500. Maya Blue was first identified in 1931, and has puzzled archaeologists, chemists and material scientists for years because of its unusual chemical stability, composition and persistent color in one of the world's harshest climates. The anthropologists have also solved another mystery, the bizarre presence of a 14-foot layer of blue precipitate found at the bottom of the Sacred Cenote (a natural well) at Chichén Itzá. This remarkably thick blue layer was discovered at the beginning of the 20th century when the well was dredged. Chichén Itzá, one of the Seven Wonders of the Ancient World, is an important pre-Columbian archeological site built by the Maya who lived on what is now the Yucatán Peninsula of Mexico. According to 16th century Spanish records, blue was the color of sacrifice for the ancient Maya. They painted their sacrificial victims blue before killing them and also before throwing them into the Sacred Cenote at Chichén Itzá. In addition, Maya Blue was used on murals, pottery, rubber, wood and other objects thrown into the cenote. Maya Blue is resistant to age, acid, weathering, biodegradation and even modern chemical solvents. It has been called "one of the great technological and artistic achievements of Mesoamerica." Scientists have long known that Maya Blue results from a unique chemical bond between the plant dye indigo, and palygorskite, an unusual form of clay that has long interior channels. Several studies have found that Maya Blue can be created by heating a mixture of palygorskite with a small amount of indigo, but they have not been able to discover how the ancient Maya themselves actually produced the pigment. The new research shows that at Chichén Itzá the creation of Maya Blue was actually a part of the performance of rituals that took place alongside the Sacred Cenote. Specifically, the indigo and palygorskite were fused together with heat by burning a mixture of copal incense, palygorskite and probably the leaves of the indigo plant. Then the sacrifices were painted blue and thrown into the Sacred Cenote. One of the keys to solving the mystery of Maya Blue production was a three-footed pottery bowl dredged from the Sacred Cenote at Chichén Itzá in 1904 and traded to The Field Museum in the 1930s which contained copal incense. Preserved in the copal were fragments of a white substance and blue pigment. Using The Field Museum's scanning electron microscope, the authors studied these inclusions and found signatures for palygorskite and indigo. From this they concluded that the Maya produced Maya Blue as part of their sacrificial ceremonies. It also helped them solve the mystery of the 14-foot layer of blue precipitate. So many sacrifices (from thousands of pots to more than 100 human beings) were thrown into the Sacred Cenote that ultimately layers of the pigment were washed from the sacrifices and settled at the bottom of the cenote. Although fully formed Maya Blue is extremely durable, it can be washed off with water, especially if there is no binder to help it adhere to the object on which it is placed.

THE BIG HISS

Biologists with the Everglades National Park in Florida confirmed a breeding population of the Burmese python in the Florida Everglades in 2003. The ancestors of these snakes were presumably of released pets. Python populations have since been discovered in Big Cypress National Preserve to the north, Miami's water management areas to the northeast, Key Largo to the southeast, and many state parks, municipalities, and public and private lands in the region. Pythons in southern Florida are bad enough but according to newly released information from the U.S. Geological Survey (USGS) these gigantic critters could find comfortable living conditions in roughly a third of the United States. Although other factors such as type of food available (can we say “pets”, boys and girls?) and suitable shelter also play a role, Burmese pythons and other giant constrictor snakes have shown themselves to be highly adaptable to new environments. Wildlife managers are concerned that these snakes, which can grow to over 20 feet long and more than 250 pounds, pose a danger to threatened and endangered species as well as to humans. Wildlife biologists have already found several endangered species inside the pythons. Control of exotic species is often prohibitively expensive once they have become established. Therefore, prevention through screening and risk assessment is of great importance, especially when protecting continental areas from invasive reptiles, said USGS invasive snake expert Gordon Rodda, also of the Fort Collins center (Gordon was here on Guam for a while and 'cut his teeth' on the brown tree snake). USGS researchers are also conducting a risk assessment for nine species of giant constrictors (including boa constrictors and yellow anacondas)(Yikes!) that are prevalent in the pet trade and as such, potential invaders in the United States. Due to be completed by early 2009, the assessment evaluates the risk of invasion for these species and the potential for social, economic, and environmental impacts. The two agencies are also developing and testing tools to control invasive snake populations and prevent their spread, especially to the Florida Keys where several listed species would be threatened by the presence of pythons or other constrictors. And you thought we had snake problems on Guam. Although I've seen plenty of brown tree snakes that were longer than me; I've never seen one that outweighed me! And finally, in case you were wondering just why you're so afraid of snakes; it turns out it's natural! Scientists from the University of Virginia have recently discovered that the fear of snakes may be bred in your bones.

OH OH OH LOOK LOOK LOOK SNAKE SNAKE SNAKE

Being able to recognize danger allowed your ancestors to pass their genes along. In a marvelously construction study preschool children and their parents were shown nine color photographs on a computer screen and were asked to find either the single snake among eight flowers, frogs or caterpillars, or the single nonthreatening item among eight snakes. In a result that may not surprise you, parents and their children identified snakes more rapidly than they detected anything else, despite the gap in age and experience. The researchers also found that both children and adults who aren't afraid of snakes are just as good at quickly identifying them as children and adults who are scared out of their wits by snakes, indicating that there may be a universal human ability to visually detect snakes whether a fear factor is involved. The researchers explain that their study doesn't prove an innate fear of snakes, only that humans, including young children, seem to have an innate ability to quickly identify a snake from among other things. One of their previous studies indicated that humans also have a profound ability to identify spiders from among non-threatening flora and fauna. Yep, if you identify it fast, you can get it before it gets you! Saturn, Maya Blue and snakes. Cruise on over to the Deep Website at www.thedeepradioshow.com to learn more about these and many other topics. Enjoy!