Nervous New Orleans Braces for Tropical Storm Gustav

Gustav's Projected Path | Video: Discovery Earth

On the eve of Hurricane Katrina's third anniversary, a nervous New Orleans watched Wednesday as another storm threatened to test everything the city has rebuilt, and officials made preliminary plans to evacuate people, pets and hospitals in an attempt to avoid a Katrina-style chaos.

Forecasters warned that Gustav could grow into a dangerous Category 3 hurricane in the next several days and hit somewhere along a swath of the Gulf Coast from the Florida Panhandle to Texas -- with New Orleans smack in the middle.

"I'm panicking," said Evelyn Fuselier of Chalmette, whose home was submerged in 14 feet of floodwater when Katrina hit. Fuselier said she's been back in her home one year this month, and called watching Gustav swirl toward the Gulf of Mexico indescribable. "I keep thinking, 'Did the Corps fix the levees?', 'Is my house going to flood again?' ... 'Am I going to have to go through all this again?'"

Taking no chances, city officials began preliminary planning to evacuate and lock down the city in hopes of avoiding the catastrophe that followed the 2005 storm. Mayor Ray Nagin left the Democratic National Convention in Denver to return home for the preparations. Gov. Bobby Jindal declared a state of emergency to lay the groundwork for federal assistance, and put 3,000 National Guard troops on standby.

If a Category 3 or stronger hurricane comes within 60 hours of the city, New Orleans plans to institute a mandatory evacuation order. Unlike Katrina, there will be no massive shelter at the Superdome, a plan designed to encourage residents to leave. Instead, the state has arranged for buses and trains to take people to safety.

It was unclear what would happen to stragglers. Jerry Sneed, the city's emergency preparedness director, said officials are ready to move about 30,000 people. Nearly 8,000 people had signed up for transportation help by late Wednesday.

At a suburban Lowe's store, employees said portable generators, gasoline cans, bottled water and batteries were selling briskly. Hotels across south Louisiana reported taking many reservations as coastal residents looked inland for possible refuge.

Steve Weaver, 82, and his wife stayed for Katrina -- and were plucked off the roof of their house by a Coast Guard helicopter. This time, Weaver has no inclination to ride out the storm.

"Everybody learned a lesson about staying, so the highways will be twice as packed this time," Weaver said.

Katrina struck New Orleans on Aug. 29, 2005, and its storm surge blasted through the levees that protect the city. Eighty percent of the city was flooded.

Though pockets of the New Orleans are well on the way to recovery, many neighborhoods have struggled to recover. Many residents still live in temporary trailers, and shuttered homes still bear the 'X' that was painted to help rescue teams looking for the dead.

Many people never returned, and the city's population, around 310,000 people, is roughly two-thirds what it was before the storm, though various estimates vary wildly.

New game enemy takes a solid day to defeat

If it's good enough for Cartman, it's good enough for Square-Enix.

The developers of the online role-playing game Final Fantasy XI seemingly borrowed a page from the Emmy-winning South Park episode "Make Love, Not Warcraft" by updating the game with one of the longest - and most physically grueling - video game fights ever. Introduced in the game's latest downloadable update, the boss monster "Pandemonium Warden" remained perfectly fit after a group of high-level adventurers wailed away at it nonstop for over 18 hours straight.

FINAL FANTASY XI SCREENS

Though the seemingly unbeatable boss will not prevent people from 'completing' the game -- persistent online games typically do not "end" like most single-player games -- it has sparked debate over what exactly the game's developers, Square-Enix, expect out of their devoted fan base. Message boards have lit up with disgruntled players calling out the company for failing to respect its very own in-game warning telling players they have "no desire to see your real life suffer as a consequence [of playing]. Don't forget your friends, your family, your school or your work."

Easy for them to say. While the beast continually healed, the gamers weren't so lucky.

"People were passing out and getting physically ill," leaders of the player guild said in a forum post. "We decided to end it before we risked turning into a horrible news story about how video games ruin people's lives."

New PSP headlines Sony's Leipzig offerings

Facing an onslaught from the Xbox 360 and Wii, and stiff portable competition from the Nintendo DS and Iphone, Sony fired off a barrage of surprise announcements at this week's Leipzig Games Convention in Germany. Top of the list was a redesign of its PSP portable platform, but a new PlayStation 3 model and a keyboard controller are also in the works.

The PSP-3000, which is the second redesign since the PSP launched in 2005, sports a new integrated microphone, while a new PS button replaces the old Home key, matching the branding of its bigger brother the PlayStation 3. The microphone will be used for the machine's Skype voice-over-IP telephony application, and should allow for voice chat in online multiplayer games.

SONY HARDWARE GALLERY

Leipzig also brought news of yet another entry in Sony's long, long list of PlayStation 3 hardware configurations: it'll hit US stores in November, sporting with a gargantuan 160 GB hard drive, by far the largest in the range so far. It'll retail for $499.99, bundled with a copy of the excellent Uncharted: Drake's Fortune, a voucher to download PAIN from the PlayStation Network, and the ubiquitous DualShock 3 rumble-enabled controller. No official word yet on whether this new top-of-the-line configuration will be backwards-compatible with earlier PlayStation models, but if the scuttlebutt is to be believed, probably not.

Lastly, if you're fed up with struggling with the PlayStation 3's clumsy on-screen keyboard, there's light at the end of the tunnel. Sony also unveiled a keyboard attachment for the regular DualShock controller, which will give text-happy gamers a full QWERTY-style selection of keys with which to enter passwords, browse the web, and send rude messages to defeated opponents. It also supports a touchpad mode for mouse-like functionality.

Bees, Fish Analyzed to Understand Serial Killers

Not a Killer But...

Studying species in the animal world helps police catch human criminals -- and vice versa. Originally developed to catch serial killers, a method called geographic profiling is now being used to study great white sharks, bats and bees.

In turn, criminologists expect that these biological studies will help refine their criminal studies, making it easier for them to catch criminals more quickly. Eventually they want to apply it to other fields, such as epidemiology.

"The same general geographic framework that criminologists use to catch criminals can be used by zoologists as well," said Kim Rossmo, co-author of an article in the Journal of the Royal Society Interface and a professor at the Texas State University Center for Geospatial Intelligence and Investigation.

"This makes us think that it can be applied to other areas as well, like epidemiology."

Rossmo originally developed geographic profiling back in the 1980's. GP, as it's known, has since been adopted by police forces across the world and has been applied in such high profile cases as the BTK Killer and the D.C. Sniper.

GP works on the assumption that, like bats, bees and sharks, serial killers don't work right next to their homes and instead travel to a more distant locations to commit crimes, creating a buffer zone around their home or work.

"They want to operate in a comfort zone, close to an area they know but not where everyone knows them," said Rossmo.

By examining the geographic locations of crimes, scientists can determine a general vicinity for the home or work location of a criminal.

The idea to apply GP to animal studies came from watching stickleback fish, said Nigel Raine, a co-author on the JRSI paper and a professor from Queen Mary, University of London.

Sticklebacks create nests for their eggs in the midst of vegetation. They keep vegetation next to their nests intact, to help hide it from predators and parasites, and travel further away to forage.

The researchers tried GP first on bats, and then bees, the subject of the JRSI paper. Another study using GP in sharks is in press.

While the technique works better for some animals (bees) and less well for others (bats), the principle is still the same. By watching where animals feed, researchers can find their homes to study the animals more effectively or to help save endangered or threatened species by identifying what geographic areas need increased protection.

While the new information is certainly valuable to biologists, criminologists are looking at the new studies as a way to perform experiments that would be unethical or flat out impossible in the human world.

"You can control the settings in biology; where you put the flowers, what kind of flowers, et cetera," said Rossmo. "You can't do that with criminal offenders."

Lorie Velarde, a GIS analyst for the Irvine California Police Department, was recently recognized for using GP to catch a burglar who operated for about 20 years.

"[GP] works great," said Velarde. "The cases where it isn't as accurate is where we don't have enough crimes," said Velarde.

That's where the animal studies will have the biggest impact, says Velarde, by refining the models to make them more sensitive so detectives and analysts can find criminals sooner.

"If there is something happening in the animal world it certainly applies to the human world as well," she said.

The next step for GP, according to Rossmo and his colleagues, is to use it to find bigger killers, like disease-carrying mosquitoes and contaminated water.

"If we see a pattern of people being infected with malaria in an area, we can use that data to find a leaking pipe or empty tire and then spray it," said Rossmo.

That technique harkens back to the very beginnings of public health, said Rossmo, when scientists identified the source of a cholera epidemic as a water pump on a certain street using a technique very similar to modern day geographic profiling.

'Dancing Plague' and Other Odd Afflictions Explained

The Dancing Plague

In July of 1518, a woman referred to as Frau Troffea stepped into a narrow street in Strasbourg, France and began a fervent dancing vigil that lasted between four and six days. By the end of the week, 34 others had joined her and, within a month, the crowd of dancing, hopping and leaping individuals had swelled to 400.

Authorities prescribed "more dancing" to cure the tormented movers but, by summer's end, dozens in the Alsatian city had died of heart attacks, strokes and sheer exhaustion due to nonstop dancing.

For centuries this bizarre event, known variously as the dancing plague or epidemic of 1518, has stumped scientists attempting to find a cause for the mindless, intense and ultimately deadly dance. Historian John Waller, author of the forthcoming book, "A Time to Dance, A Time to Die: The Extraordinary Story of the Dancing Plague of 1518," studied the illness at length and has solved the mystery.

"That the event took place is undisputed," said Waller, a Michigan State University professor who has also authored a paper on the topic, which has been accepted for publication in the journal Endeavour.

Waller explained that historical records documenting the dancing deaths, such as physician notes, cathedral sermons, local and regional chronicles, and even notes issued by the Strasbourg city council during the height of the boogying rage, all "are unambiguous on the fact that (victims) danced."

"These people were not just trembling, shaking or convulsing; although they were entranced, their arms and legs were moving as if they were purposefully dancing," he said.

Possible Causes

Eugene Backman, author of the 1952 book "Religious Dances in the Christian Church and in Popular Medicine," sought a biological or chemical origin for the dancing mania. Backman and other experts at the time believed the most likely explanation was ergot, a mold that grows on the stalks of damp rye. When consumed unknowingly in bread, the mold can trigger violent convulsion and delusions but not, Waller says, "coordinated movements that last for days."

While at Australia's James Cook University, sociologist Robert Bartholomew proposed a theory that the dancers were performing an ecstatic ritual of a heretical sect, but Waller counters, "there is no evidence that the dancers wanted to dance."

"On the contrary," he added, "they expressed fear and desperation," according to the written accounts.

Unusual Events Preceded the Epidemic

A series of famines, resulting from bitter cold winters, scorching summers, sudden crop frosts and terrifying hailstorms, preceded the maniacal dancing, Waller said. Waves of deaths followed from malnutrition. People who survived were often forced to slaughter all of their farm animals, secure loans and finally, take to the streets begging.

Smallpox, syphilis, leprosy and even a new disease known as "the English sweat" swept through the area.

"Anxiety and false fears gripped the region," Waller said.

One of these fears, originating from a Christian church legend, was that if anyone provoked the wrath of Saint Vitus, a Sicilian martyred in 303 A.D., he would send down plagues of compulsive dancing.

Waller therefore believes a phenomenon known as "mass psychogenic illness," a form of mass hysteria usually preceded by intolerable levels of psychological distress, caused the dancing epidemic.

Praying to St. Vitus

Mass Hysteria

Ivan Crozier, a lecturer in the Science Studies Unit at the University of Edinburgh, told Discovery News that he "agrees completely" with Waller's conclusion.

"His cultural explanation, combined with a contextualized view of the conditions in which people lived at the time on the Rhine and Mosel, is very convincing and is superior to the arguments about ergot, which is a compound like LSD," Crozier said.

"Ergot gave people visions, not energy to dance," he added.

Crozier is a world authority on yet another mass hysteria epidemic: koro.

Since at least 300 B.C., plagues of koro -- an irrational male fear that one's genitals have been stolen or are fatally shrinking into the body -- have swept through various parts of the world, particularly throughout Africa and Asia. Most recently, a 1967 outbreak, documented in the Singapore Medical Journal, caused over 1,000 men to use pegs and clamps in hopes of protecting themselves from the gripping fear.

"In both cases we see cultural issues impacting on collective behavior," Crozier said, explaining that preexisting superstitions, fears and beliefs surrounding both koro and the dancing epidemic led to group beliefs turning into "collective action."

Waller explained that victims often go into an involuntary trance state, fueled by psychological stress and the expectation of succumbing to an altered state.

"Thus, in groups subject to severe social and economic hardship, trance can be highly contagious," he said.

More Deadly Dancing, And Laughing

At least seven other outbreaks of the dancing epidemic occurred in medieval Europe, mostly in the areas surrounding Strasbourg. In more recent history, a major outbreak occurred in Madagascar in the 1840's, according to medical reports that described "people dancing wildly, in a state of trance, convinced that they were possessed by spirits."

Perhaps the most unusual documented case of mass psychogenic illness was the Tanganyika Laughter Epidemic of 1962. A paper published the following year in the Central African Journal of Medicine described what happened.

Triggered by a joke among students at a Tanzania boarding school, young girls began to laugh uncontrollably. At first there were spurts of laughter, which extended to hours and then days.

The victims, virtually all female, suffered pain, fainting, respiratory problems, rashes and crying attacks, all related to the hysterical laughter. Proving the old adage that laughter can be contagious, the epidemic spread to the parents of the students as well as to other schools and surrounding villages.

Eighteen months passed before the laughter epidemic ended.

Curing the Mind

According to medical epidemiologist Timothy Jones, an assistant clinical professor of preventative medicine at the Vanderbilt University School of Medicine, who also reported an incident of hysteria in Belgium following soft-drink consumption, "Outbreaks of psychogenic illness are likely to be more common than is currently appreciated, and many go unrecognized."

Jones recommends that physicians treating such problems "attempt to separate persons with illness associated with the outbreak," conduct tests to rule out other causes, monitor and provide oxygen for hyperventilation, attempt to minimize the individual's anxiety, notify public health authorities and seek to assure patients that, while their symptoms "are real…rumors and reports of suspected causes are not equivalent to confirmed results."

Aside from their medical interest, Waller believes such epidemics, particularly those from past centuries, are "of immense historical value."

He said the dancing plague "tells us much about the extraordinary supernaturalism of late medieval people, but it also reveals the extremes to which fear and irrationality can lead us."

He added, "Few events in my view so clearly show the extraordinary potentials of the human mind."

Harsh Climate Change Once Fell Swiftly

It's one of the most dramatic examples of climate change in Earth's history, and scientists now say it happened almost entirely in one year's time.

Thirteen thousands years ago, Europe was much like it is today -- cool but temperate, with great forests carpeting the land. Ice sheets still nibbled at Finland and Sweden, but for much of the continent the last Ice Age was a distant memory.

Suddenly, the climate went haywire. Warm Gulf Stream currents that brought heat from the equator up toward the pole began to fail. Temperatures plummeted 3 to 4 degrees Celsius, and stayed that way for a millennium.

Now scientists believe they've pinpointed the exact time the northern hemisphere was plunged back into a deep freeze. Examining sediments preserved at the bottom of a remote lake in western Germany, they found that what's known as the Younger Dryas cold period took just a year to sweep across the continent, starting in the autumn, 12,679 years ago.

Led by Achim Brauer of the German Research Center for Geosciences in Potsdam, Germany, the team believes such a quick, profound change in climate could only have been brought about by a shift in winds across the northern hemisphere.

Today prevailing winds in the northern hemisphere above the tropics tend to blow from the southwest to the northeast. Air that flows over Texas soon crosses the Atlantic and winds up over Norway.

As it travels the air passes over the Gulf Stream, a warm ribbon of water pouring northward from the tropics. The balmy air brings heat to Europe, which otherwise would be chilly.

The same was probably true just before the Yonger Dryas set in. But as the vast Ice Age glaciers retreated, their melt water flowed into the northern reaches of the Atlantic Ocean. The injection of fresh water made the sea easier to freeze, and a new skin of ice began advancing south.

The warm conveyor belt of Gulf Stream waters soon ebbed to a trickle. And as the sea ice advanced, the winds shifted into a west-east pattern. Within a year the breezes that warmed Europe had vanished.

"The Younger Dryas continues to surprise us in providing a message as to how quickly climate change can occur," said Daniel Sigman of Princeton University in N.J. Sigman is a co-author on the study, which appears today in the journal Nature Geoscience.

"The hypothesis on this paper is I think a very nice one," Richard Alley of Pennsylvania State University said. Winds tend to blow parallel to temperature gradients, and the gradient between sea ice and open water can be very sharp, up to 40 degrees C.

The sea ice border probably extended in a rough west to east direction, and the winds would've followed it, bringing cold air to much of Europe.

"You can think of it as a front pushing down across Germany," Alley said. "Winds go where something's pushing them hard. A steep temperature gradient along the edge of sea ice would push hard in an east-west direction."

Universe's Spiral Galaxy Population Evolving

New generations of small spiral galaxies are three times as likely to sport a central bar of stars as their counterparts seven billion years ago, a census of more than 2,000 galaxies shows.

The finding indicates that the galaxies, which are believed to build up over time by merging with other galaxies, are still evolving in form as the universe ages, said Kartik Sheth at the California Institute of Technology in Pasadena.

Spiral galaxies were around in the universe's early days, but only about 20 percent of them had the bar-shaped cores so prevalent in newer galaxies. Sheth's team found that spiral galaxies younger than about seven billion years -- roughly half the age of the universe -- were three times as likely as older generations to have bars.

The structures, which are found in two-thirds of all spiral galaxies including our own Milky Way, form when the orbits of stars in the disk become unstable and drift from circular paths.

"It turns out that stars prefer to be in these bar orbits," Sheth told Discovery News. "It's a lower-energy state."

Over time, more and more stars are locked into elongated orbits, making the bar more stable, added Bruce Elmegreen, an IBM Research Division astrophysicist.

The small, low-mass spiral galaxies are the most dynamic now. Larger-mass spirals with bar structures developed them, on average, much earlier in their history.

"When the universe was forming, the biggest things formed first. Then the action moved down to the wimpier guys that are still becoming mature," Sheth said.

Is the World's Largest Shark Shrinking?

Humans have over-exploited the whale shark -- the world's largest living fish -- to such a degree that the ocean giants are actually shrinking in size, according to new research.

The whale shark population has also fallen by approximately 40 percent over the past decade in Western Australian waters, the new study has found, suggesting that this once prevalent shark, which can reach lengths up to 42 feet, is undergoing a severe decline in certain regions.

"We are all very alarmed at our findings, which really did defy our expectations," co-author Ben Fitzpatrick, a University of Western Australia biologist, told Discovery News.

The researchers analyzed the largest-ever database of sightings and size information on whale sharks. The database represents a long-term, continuous record of sightings -- 4,436 in total -- as well as photo ID information concerning age and size, all pertaining to whale sharks at Ningaloo Reef, Western Australia.

Because the sharks gather seasonally at the picturesque reef from March to June, a profitable industry has been built around "dive with sharks" activities. Usually by air sightings, tour operators regularly gather information on the sharks, compiled in the extensive database.

Fitzpatrick and his colleagues not only detected the population drop at the reef, but they also discovered the sharks have shrunk in body length by an average of over 6.5 feet. The overall reduction appears to be due to the disappearance of older, larger females, along with some males, within whale shark groups.

"I think it is mostly because the larger animals are being hunted for food and other products, such as for soup fins," explained Barry Brook, another co-author of the study and director of the Research Institute for Climate Change and Sustainability at The University of Adelaide.

"The larger the fin, the more valuable it is," Brook added.

The findings are published in the latest issue of Biological Conservation.

The scientists believe a selection effect may also be at work, whereby pressures are forcing smaller, younger whale sharks to breed earlier, but they believe this is just "a minor piece of the puzzle."

Brook said that while the whale sharks enjoy protection in Ningaloo Reef waters, the sharks migrate over large distances, often traveling thousands of miles.

"Artisanal fisheries via harpoons for meat, for example, off the coasts of India and Indonesia, but mostly by Taiwanese and Chinese commercial fisheries" are likely responsible for the declines, he said, adding that whale shark meat is referred to as "tofu fish" due to its texture, which is also prized in shark fin soup and Chinese medicine.

Ship strikes also tend to kill larger adults, he said, though evidence for the strikes is hard to compile since resulting deaths would usually remain unknown.

These latest findings counter a study late last year by Brad Norman and Jason Holmberg of ECOCEAN, a research education and conservation organization. That report, based on multiple underwater images of the sharks, concluded that Ningaloo Reef whale sharks are thriving. Norman did, however, admit to Discovery News that the species is "rare" and "vulnerable to extinction."

Brook and his colleagues have authored a written response to Norman's paper, which is still under consideration by the journal, Ecological Applications. They say that while whale sharks receive some trade protection from the Convention on International Trade in Endangered Species, "it is difficult to police non-international trade or local hunting by indigenous people."

The migratory habits of whale sharks, Brook said, "mean it is impossible to protect the Ningaloo population once the sharks leave Australian waters for Indonesia and the Philippines."

The researchers urge officials to establish well-enforced international protection for the sharks. They also hope that collaborative tagging studies in the future will help to better identify and monitor whale shark migration routes.

Distant Wildfires Cause Arctic Cooling

It's hard to imagine that the raging blazes of wildfires could cool things down, but that is the conclusion of a new study.

Robert Stone of the University of Colorado, Boulder, and colleagues report that wildfire smoke that reaches the Arctic has the net effect of cooling the surface by reducing the amount of sunlight that makes it through.

The effect of smoke and other aerosol particles in the atmosphere is a large source of uncertainty in climate models. The new work removes some of that uncertainty.

"They have given us a much better understanding of what the effect of smoke is on the climate system," said Alan Robock of Rutgers University in New Brunswick, N.J.

The team made measurements in 2004 when widespread wildfires in Alaska and western Canada sent large plumes of smoke into the Arctic, including over their research station in Barrow, Alaska.

They measured the density of the smoke in the atmosphere and the net amount of energy from the sun hitting the surface to find the relationship between the amount of smoke and the reduction in energy reaching the ground.

When plugged into models, this information helped predict how the smoke would behave over other surfaces, such as the ocean, where the researchers could not make measurements.

The team found that smoke particles tend to absorb energy well above ground, but because they also reflect incoming radiation, the net effect at the surface is cooling. They published their results today in the Journal of Geophysical Research-Atmospheres.

The effect is greatest over dark surfaces, including the ocean, where most of the energy that makes it through is absorbed. Smoke still reduces the amount of radiation that hits ice-covered surfaces, but since these bright areas already reflect most of the radiation that hits them, smoke cover doesn't change the net amount of energy at the surface by as much.

"If the climate warms and you have more severe and frequent wildfires, that will have this tendency to cool the surface," Stone said. It is not yet possible to say how significant of an effect this might be, he added.

California's ongoing wildfires are unlikely to have a large effect on the Arctic, he said, because circulation patterns don't favor California's air masses reaching the Arctic.

However, "every year there are tremendous natural wildfires in Siberia," Stone said. "Once they take off they can burn for weeks and months." That air is readily carried to the Arctic, he added.

The smoke may have additional effects that Stone's models don't account for. For instance, the warming effect of smoke particles at higher altitudes may evaporate clouds, or the particles may also act to seed cloud formation, increasing cloudiness.

"This is a natural phenomenon, in that lightning starts the fires," Robock said. "But it's an anthropogenic phenomenon if the trees are more susceptible to fires because of greenhouse gases."

Earth, As E.T. Would See It

In the ongoing quest to find life elsewhere in the universe, it helps to have a role model. Presently, however, there's just one to choose from: Earth.

"It is terra-centric of us," said planetary scientist Sara Seager. "It's like that story of a person who loses their keys on a dark sidewalk and looks for them under the street light because that is the only place he can see."

Seager, with the Massachusetts Institute of Technology, is among dozens of researchers in the hunt for Earth-like worlds. She spends her time modeling what the atmospheres and interiors of planets outside our solar system might look like. Many of her ideas come from the home planet.

"If we get data, we want to know what it means," she said in an interview with Discovery News.

Twinkle, Twinkle

For example, at a planet-hunters conference in France last month, researchers reported that from the perspective of space, light from Earth twinkles as clouds pass in and out of view.

"A distant extraterrestrial observer would see Earth as a point source of light that varies in brightness in a repeating, predictable pattern, just like spots on a spinning ball," Science magazine reported in an article last month about the research, which was headed by Enric Palle of the Institute of Astrophysics of the Canary Islands.

If similar patterns were discovered on an extrasolar Earth, scientists might be able to look for what would appear to be variations in the planet's rotation, a phenomenon actually due to clouds.

On Earth, clouds indicate the presence of water vapor, and water, as far as scientists know, is a key ingredient for life.

This sort of detective work is what scientists searching for habitable planets have available. Direct imaging of large planets, let alone smaller Earth-sized worlds, is not possible with the telescopes and technologies that exist today.

The Next Pale Blue Dot

Even with the sophisticated observatories in the planning stages, such as NASA's Terrestrial Planet Finder, scientists' best hope is to discern a pale blue dot.

Their most important tool will not be a camera, but a spectrograph, which can split light bouncing off a target planet into individual wavelengths, much like visible light can be broken into a rainbow array of colors. Chemicals in a planet's atmosphere will absorb particular wavelengths, resulting in dropouts, like black lines in the rainbow.

"So from afar, we can see that there's water vapor, for example, which may be an indication of water on the planet's surface," Seager explained. "We can detect oceans, maybe weather."

After water, oxygen would be the next key find. Earth's atmosphere is rich with oxygen due to plant life. Uninhabited sister planet Venus, in comparison, has just a trickle.

"You can't generate that much oxygen by geologic processes," Seager said. "Life produces the same thing that can be produced naturally but, there's lots more of it."

Earth From a Distance

Among Seager's projects is a recycled asteroid probe now on an extended mission to hunt for extrasolar planets as it makes it way toward a comet. NASA on Thursday released one of the first offerings from Deep Impact's second life: a movie of Earth.

"It helps the search for other life-bearing planets in the universe by giving insights into how a distant, Earth-like alien world would appear to us," said University of Maryland astronomer Michael A'Hearn, the lead scientist for the Deep Impact extended mission, called EPOXI.

For example, in the video, sunlight can be seen bouncing off Earth's oceans.

"Similar glints to be observed from extrasolar planets could indicate alien oceans," said Drake Deming, with NASA's Goddard Space Flight Center in Greenbelt, Md.

The team also found eye-popping reflections of the planet's plant-covered continents in near-infrared imagery taken by Deep Impact.

"They're brighter in that wavelength," Seager observed. "I didn't really appreciate how that makes the continents stand out until I saw it."

Tiny Bug Threatens to Take Down U.S. Citrus Crops

Border agents have stepped up searches and hundreds of traps have been placed on the California-Mexico line in an aggressive campaign to stop a tiny bug from bringing in a disease farmers say could wipe out the $1.3 billion citrus industry here.

Already, Asian citrus psyllid has hurt citrus production in parts of China and infested millions of dead and dying trees in Florida and Brazil. Growers say the bug has the potential to be more damaging than the Mediterranean fruit fly because entire groves -- not just fruit -- are at risk.

"This is not one more thing, this might be the last thing," said Al Stehly, who manages 200 acres of oranges near Valley Center in San Diego County.

The tiny psyllids are the only transmitters of the disease, officially known by its Chinese name, huanglongbing, or "yellow dragon disease" for its visual effect on leaves. In the U.S., growers call it "citrus greening" disease because fruit fails to ripen.

Psyllids feed on the liquid inside citrus leaves, and once a psyllid eats from an infected tree, it carries the bacteria for life. Diseased trees wither and die within a few years.

More than 22 years of research by the U.S. Department of Agriculture has not yet revealed genetic or biological controls for the disease.

"There is no place in the world this disease is under adequate control," said plant pathologist Tim Gottwald of the USDA's agricultural research service in Florida and one of the world's leading authorities on citrus greening. "We don't have an adequate strategy at this moment."

Gottwald likens the potential impact to Dutch elm disease, which has wiped out nearly the entire elm population in England and Europe.

Recent news that the bug was found within four blocks of the San Diego County line sent orange juice futures up and spread panic through the industry. Industry officials worry international trade could be affected, as California supplies 85 percent of the U.S. fresh orange market, and 30 percent of the state's production is shipped overseas.

"The sky could fall unless everybody is constantly on top of everything on this," said Christopher Mundt, a plant epidemiologist at Oregon State University who studies grains, but was asked recently to bring fresh eyes to the citrus problem. "There's not going to be much room for error on this one."

DNA tests on 138 psyllids trapped so far in Tijuana have given no indication those bugs carry the bacteria.

Still, officials are being vigilant.

Border patrol agents have stepped up monitoring for orange tree cuttings and even certain types of curry leaves at airports and crossings. Some nursery ornamentals such as mock oranges and certain orange jasmines can be silent carriers of the disease. Officials also worry that citrus greening already could be present in California but until now has lacked a carrier.

California agricultural officials have placed 1,065 traps in a 120-square-mile grid at the border in San Diego and Imperial counties.

"Unfortunately, pests don't observe international borders," said Steve Lyle of the California Department of Agriculture. "Should the pest cross the border, and there's little reason to believe that it won't, we'll be able to detect it as fast as we can."

After that, agriculture officials say they aren't sure what they'll do and that "response options are under evaluation."

The California Citrus Research Board also is launching its own fight Friday, enlisting growers and master gardeners from San Diego to Ventura to help bait and trap the bug by pruning sentinel trees to encourage the new growth the psyllids favor. It will form a line of defense against the San Joaquin Valley, where 80 percent of the state's oranges grow.

The group, funded by state growers, will also set up labs in Riverside and Tulare counties to expedite testing for the disease on suspect trees. The cost will be about $1.5 million a year.

"We're throwing everything at it but the kitchen sink," said Ted Batkin, the board's president.

The bugs arrived in the U.S. in Florida in 1998, and the disease was in full-swing by 2005. Costly spraying of a variety of insecticides toxic to bees

Florida growers have contributed more than $20 million for research this year.

When the disease hits, growers must decide whether to cull and replace trees, or abandon operations.

"We can slow it down," Stehly said, "but we can't stop it. I'll be out of business in a few years."