Sunday, February 28, 2010
Saturday, February 27, 2010
Friday, February 26, 2010
First described in 2008, the exoplanet-WASP-12b is a Jupiter-like world that orbits its host star so tightly a year lasts just 26 hours.
This closeness means that a combination of heat from the star and from a gravitational tug-of-war called tidal heating brings the surface temperature to more than 4,700 degrees Fahrenheit (2,600 degrees Celsius).
According to a report in National Geographic News, new data show that WASP-12b's atmosphere is also being puffed up by the star's heat to the point that some of its gases are escaping.
"But rather than being blown away by stellar winds, the lost atmosphere might be getting pulled toward the star to form a hot ring around the star," said study leader Shu-lin Li, an astronomer at Peking University in Beijing.
In fact, WASP-12b is losing mass so fast, it will likely disappear before its aging star has a chance to swallow the planet whole.
"The sun like host star, known as WASP-12, is now about two billion years old, which means it's nearing the end of its life," said Heather Knutson, an astronomer and exoplanet researcher at the University of California, Berkeley.
"Normally, dying sun like stars grow into red giants, and their outer atmospheres expand to engulf nearby planets," said Knutson.
WASP-12b has expanded to six times Jupiter's volume, even though the planet is only about 1.4 times Jupiter's mass.
It is predicted to become a red giant within about a hundred million years.
But "this star will not have WASP-12b to 'eat,' because the planet would have been totally disrupted long before then, within ten million years," said study co-author Douglas Lin of the University of California, Santa Cruz.
"Overall, WASP-12b presents scientists with a rare chance to study a planet that can survive, for any length of time, so close to a star," said Knutson.
"They're in such extreme environments. You can imagine scenarios in which there are other planets we didn't see that got that close and didn't make it," she added.
The medics involved in the incident on Tuesday have both been sacked, the news agency Agencia Estado said.
According to the Folha de Sao Paulo newspaper, a 32-year-old woman, Gislaine Santana, was in labor requiring a caesarian section when the doctors' fight erupted.
"It was a big fight. They ended up rolling around on the floor,'' Ms Santana's husband, Gilberto Melo Cabreira, said.
"And my wife was screaming for them to stop."
A third doctor came into the room 90 minutes later to perform the caesarian, but by that time the woman had delivered her baby girl stillborn.
"I don't want to make accusations," the husband said.
"But I can testify to one thing: up to the birth, my daughter was in full health."
The Department of Fisheries and Oceans in Corner Brook intends to check out the Lower Cove site today hoping to find some answers for the question of many curious onlookers who went there to see for themselves what Lovell found during a Wednesday afternoon walk on the beach.
“It would be nice to see if anyone knows what it is,” says Lovell. “First I thought it was a seal washed up (on the high tide earlier in the day), but when I went down to check on my boat that evening, I walked over to see and then I knew it wasn’t a seal.
“But, I don’t know what it is.”
Of unknown origin and species, so far, the odd-looking seaside carcass sits high and dry on the low tide, its approximately 15-foot length includes a pointed, 10-foot tail twisted in the sand, conjuring up Loch Ness monsters for some.
The animal, bearing a single flipper-like appendage on its right side, appears to have been decapitated and shows other signs of damage.
“I didn’t know what to think of it,” says Rich Park, also among the first to see it close up.
The long tapered tail on the squared torso of the carcass caused him to initially think the large hunk of flesh might be a tentacle off a giant squid Park said, but on closer inspection it became clearer what the protrusion was not that. It got hair on it in spots. I couldn’t (determine) what it was.”
“I’ve lived here all my life and never seen anything like it,” says Basil Park, who went Thursday went to take a look with friends and brothers Gilbert and Ernie Park, and neither one of them could say they knew what it was.
“There’s fishermen around here who fished all their lives and they couldn’t tell you.”
John Lubar with DFO says the Corner Brook office receives a number of calls from residents around the region each year reporting seals in brooks or to have rotting carcasses of whales or other dead things removed from a shoreline, but claims reports of unknown creatures from the deeps washing up are rare.
Common knowledge of the McIvers find spread by word of mouth over the past few days and at least one visitor to the site photographed the carcass and has posted it on Facebook.
DFO expects to have personnel in McIvers to do an inspection of Lower Cove by noon today.
Thursday, February 25, 2010
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The orca whale grabbed the trainer by the waist while she was talking about the whale, according to a witness. Another report had the trainer slipping or falling into the whale's tank.
Emergency personnel pronounced the trainer dead at the scene. Her name has not been released.
The whale is Tilikum, a 12,300-pound bull orca.
The attack occurred in the park's Shamu Stadium. The killer whale show has been indefinitely suspended and part of the park has been closed because of the attack.
In July 1999, the body of a naked man was found scratched, bruised and draped over 5-ton Tilikum. Daniel Dukes, 27, reportedly made his way past security at SeaWorld, remaining in the park after it had closed. Wearing only his underwear, Dukes either jumped, fell or was pulled into the frigid water of Tilikum's huge tank.
An autopsy determined Dukes died of hypothermia in the 50-degree water. But the report also found it appeared Tilikum bit the man and tore off his swimming trunks, likely believing he was a toy to play with.
An investigation into what may have prompted Wednesday's incident was beginning.
Has the Cetacean Uprising of 2010 begun? With Shamu killing a trainer at SeaWorld this afternoon, we have to ask: was this merely an act of workplace violence, or was the whale a terrorist who was angry about being forced to pay his taxes even though he isn’t even a human? Or was Shamu talking to a Yemeni cleric on the Internet who convinced him that this was a good way to go to heaven as an Islamist martyr?
All joking aside, an Orca or killer whale killed an unnamed trainer at SeaWorld in Florida today, and all live killer whale shows have been suspended, according to the Orlando Sentinel. Of course, Shamu is not just one whale – it can be any number of male or female whales kept by the park.
And, it’s not the first time the trainers have had problems with ‘Shamu.’ Here is a video from the show Maximum Exposure that shows a whale wigging out during a training session:
The Orlando Sentinel described today’s attack in this manner:
"Park guest Victoria Biniak told Local 6 that the trainer was a veteran of SeaWorld and had just finished explaining to the audience what they would see during the performance.
At that point, Biniak said, the whale came up from the water and grabbed the woman.
The whale “took off really fast in the tank, and then he came back, shot up in the air, grabbed the trainer by the waist and started thrashing around, and one of her shoes flew off.”
I guess it’s necessary to remind everyone that killer whales are called ‘killers’ for a reason. They’re meat eaters, and it’s hard to know when they’re having a bad day. A pity for this trainer, and all the people watching the show, that this was one of them.
Also, can someone make sure the orcas are having a good day the next time Halle Berry decides to hang out with her close, personal friend Shamu, as she does in the picture below?
Wednesday, February 24, 2010
A head-on collision was averted between a spent upper stage from a Chinese rocket and the European Space Agency's (ESA) huge Envisat Earth remote-sensing spacecraft.
Space junk tracking information supplied by the U.S. military, as well as confirming German radar data, showed that the two space objects would speed by each other at a nail-biting distance of roughly 160 feet (50 meters).
ESA's Envisat tips the scales at 8 tons, with China's discarded rocket body weighing some 3.8 tons. A couple of tweaks of maneuvering propellant were used to nudge the large ESA spacecraft to a more comfortable miss distance.
But what if the two objects had tangled?
Such a space collision would have caused mayhem in the heavens, adding clutter to an orbit altitude where there are big problems already, said Heiner Klinkrad, head of the European Space Agency's Space Debris Office in Darmstadt, Germany.
It turns out, Klinkrad told SPACE.com, that 50 percent of all the close conjunctions that Envisat faces are due to the lethal leftovers from China's January 2007 anti-satellite test, as well as chunks of junk resulting from last year's smashup between an active U.S. Iridium satellite and a defunct Russian Cosmos spacecraft.
Klinkrad joined several orbital debris experts that took part in the 33rd Annual Guidance and Control Conference organized by the Rocky Mountain Section of the American Astronautical Society. The five-day meeting began Feb. 5.
Significant progress has been made by the U.S. and the international aerospace communities in recognizing the hazards of orbital debris, reported , chief scientist for orbital debris at the NASA Johnson Space Center in Houston, Texas.
Johnson added that steps are being taken to reduce or eliminate the potential for the creation of new debris. However, "the future environment is expected to worsen without additional corrective measures," he noted.
During 2009, Johnson reported, five different NASA carried out collision avoidance maneuvers: a (TDRS-3), Cloudsat, Earth Observing Mission 1, Aqua, and Landsat 7. Also, the and the took collision avoidance actions, he said.
The worst thing that could happen, according to ESA's Klinkrad, is the International Space Station (ISS) receiving a fatal hit. The space station is currently home to five astronauts representing the U.S., Russia and Japan.
"A penetrating object hitting the ISS, and possibly causing a casualty onboard . . . I think that would be the most dramatic case we could have," Klinkrad suggested. Such an incident might turn public opinion against human spaceflight, he said.
Collaboration on the increase
One bit of good news in all this orbital riff-raff.
Due to last year's satellite crash between the Iridium and Cosmos spacecraft, Johnson explained that the Joint Space Operations Center (JSpOC) of the U.S. Strategic Command now conducts conjunction assessments for all operational spacecraft in Earth orbit, regardless of ownership nationality.
"To be honest, a year ago, we couldn't even have hoped to have done this," Johnson told SPACE.com.
"It's really a consequence of the collision last year. People have been talking about this for years. But now we've made the commitment . . . that this is something that needs to be done and can be done relatively easily," Johnson said.
Klinkrad concurred. "The collaboration is getting even closer now," he said.
Duck or pluck?
Playing dodge ball with high-speedis one tactic. But there is also a growing interest in removing the most troublesome objects — perhaps an annual quota of some sort.
Targeted would be specific inclination bands and altitude regimes, Klinkrad said. But prior to implementing debris remediation measures on a global scale, technical, operational, legal and economic problems must be overcome.
Klinkrad and NASA's Johnson provided a wearisome appraisal of the future.
Even with an immediate halt of launch activities, spacefaring nations will be dealing with an unstable low-Earth orbit environment in some altitude and inclination bands. This would be a consequence of about 20 catastrophic collisions within the next 200 years, the two orbital debris experts explained.
Some orbit altitudes already have critical mass concentrations that will trigger "collisional cascading" within a few decades, unless debris environment remediation measures are introduced.
The Kessler Syndrome
The idea of debris creating debris was put in motion by Donald Kessler, along with fellow NASA researcher, Burton Cour-Palais, back in 1978.
Their research suggested that, as the number of artificial satellites in Earth orbit increases, the probability of collisions between satellites also increases. Satellite collisions would produce orbiting fragments, each of which would increase the probability of further collisions, leading to the growth of a belt of debris around the Earth.
Kessler told SPACE.com that the disorder fits into much more complex natural laws that include the evolution of the solar system, as well as meteoroids, meteorites, and climate-changing asteroids.
Kessler is now an orbital debris and meteoroid consultant in Asheville, North Carolina.
"There is nothing complex about what is called the 'Kessler Syndrome' . . . it is just the way nature may have converted a disorderly group of orbiting rocks into an orderly solar system . . . although nature reminds us with a large asteroid or comet collision every few million years that it isn't quite finished yet.
"In the case of orbital debris, this collision process is just starting," Kessler explained.
Consequently, nobody should be surprised that as orbital debris models became more complex — and as more data is obtained — the same conclusion holds, Kessler said.
"The future debris environment will be dominated by fragments resulting from random collisions between objects in orbit, and that environment will continue to increase, even if we do not launch any new objects into orbit," Kessler concluded.
- Some of the Worst Space Debris Moments in History
- India Developing Anti-Satellite Spacecraft
- Video — The Expanding Danger of Space Junk
Leonard David has been reporting on the space industry for more than five decades. He is past editor-in-chief of the Space World magazines and has written for SPACE.com since 1999.
Tuesday, February 23, 2010
How quickly time passes depends on where you are, a lesson learnt the hard way by that first-time reviewer of Wagner who observed: "After two hours, I looked at my watch and found that 20 minutes had gone by."
For physicists rather than opera-lovers, relativity was famously expressed in 1915 by Albert Einstein who suggested, among other things, that the flow of time was affected by the force of gravity.
Clocks will run faster the farther they are from a large gravitational source and run slower they closer they are to it, goes the theory.
Various experiments have been carried out to explore Einstein's insight.
They include a 1976 exploit in which an atomic clock was taken on a 115-minute rocket ride to a point some 10,000 km above Earth, and was found to measure more time compared to a counterpart on Earth.
Now physicists in the United States have gone a step further.
They have proved Einstein's theory with an accuracy 10,000 times greater than before, according to a paper published in the British journal Nature.
A team that included Nobel winner Steven Chu - now U.S. energy secretary - used a trap that involved three lasers that zapped waves of caesium atoms, making them move up and down like a fountain.
The waves were used as super-fast clocks, oscillating at nearly a million billion billion times per second.
The team's technique invoked a strange-but-true phenomenon of quantum mechanics: that an atom can be excited into two states at the same time.
In one of the states, the atom was "pushed" by laser pulse one tenth of a millimeter (0.004 of an inch), giving it a minute boost away from Earth's gravitational field. In the other, it remained unmoved.
A split-second later, a second laser flash sent the high-flying atoms downwards, and the stationary ones upward. The two states were then reconstituted in a single atom by a third laser pulse.
The task was then to measure the difference in energy oscillation in the waves during these states.
During the 0.3 seconds they spent in freefall, the waves oscillated about a million extra times - in other words, a wee bit more time elapsed as a result of the brief reduction in gravitational pull.
The numbers should be put in perspective, said Holger Mueller, an assistant professor of physics at the University of California at Berkeley.
"If the time of freefall was extended to the age of the universe, 14 billion years, the time difference between the upper and lower routes would be a mere one hundredth of a second, and the accuracy of the measurement would be 60 picoseconds, the time it talks for light to travel about half an inch (1.27 cm)."
The results add further gloss to Einstein's renown, he said. "This experiment demonstrates that gravity changes the flow of time, a concept fundamental to the theory of general relativity," Mueller said.
Practical benefits also stem from it.
Global Positioning Satellites (GPS) work by sending out precisely timed signals, calibrated by atomic clocks, which are then triangulated to provide a position on the surface of the Earth.
If the best available clocks were used in GPS satellites, satnav users could find their position to the millimetre - but this accuracy could be wrecked if the satellite were moved by just a metre (yard) in altitude, said Mueller.
Prototaxites have sparked controversy for more than a century. Originally classified as a conifer, scientists later argued that it was instead a lichen, various types of algae or a fungus. Whatever it was, it stood in tree-like trunks more than 20 feet tall, making it the largest-known organism on land in its day.
“No matter what argument you put forth, people say, well, that’s crazy. That doesn’t make any sense,” said C. Kevin Boyce, Assistant Professor in Geophysical Sciences at the University of Chicago. “A 20-foot-tall fungus doesn’t make any sense. Neither does a 20-foot-tall algae make any sense, but here’s the fossil.”
Plant-like polymers have been found in the fossils, but nutritional evidence supports heterotrophy, which is not commonly found in plants. These are a few of the confounding factors surrounding the identification of Prototaxites fossils.
Prototaxites existed during the Late Silurian to Late Devonian periods-- approximately 420-370 million years ago (ma). Prototaxites fossils have a consistent tubular anatomy, composed of primarily unbranched, non-septate tubes, arranged in concentric or eccentric rings, giving the fossils an appearance similar to that of a cross-section of a tree trunk. The fossil "trunks" vary in size and may be up to 8.8 m long and 1.37 m in diameter, making Prototaxites the largest organism on land during the Late Siluarian and Devonian periods.
Dr. Linda Graham, one of the world's experts in the evolutionary origin of land plants at the University of Wisconsin, and her colleagues believe that they have resolved this long-standing mystery.
Their hypothesis is that Prototaxites fossils may be composed of partially degraded wind-, gravity-, or water-rolled mats of liverworts that are associated with fungi and cyanobacteria. This resembles the mats produced by the modern liverwort genus Marchantia. The authors tested their hypothesis by treating Marchantia polymorpha in a manner to reflect the volcanically-influenced, warm environments typical of the Devonian period and compared the resulting remains to Prototaxites fossils. Graham and her colleagues investigated the mixotrophic ability of M. polymorpha by assessing whether M. polymorpha grown in a glucose-based medium is capable of acquiring carbon from its substrate.
"For our structural comparative work," Graham said, "we were extremely fortunate to have an amazing thin slice of the rocky fossil, made in 1954 by the eminent paleobotanist Chester A. Arnold."
Their structural and physiological studies showed that the fossil Prototaxites and the modern liverwort Marchantia have many similarities in their external structure, internal anatomy, and nutrition. Despite being subjected to conditions that would promote decomposition and desiccation, the rhizoids of M. polymorpha survived degradation, and with the mat rolled, created the appearance of concentric circles. The fungal hyphae associated with living liverworts also survived treatment, suggesting that the branched tubes in fossils may be fungal hyphae. The very narrow tubes in the fossils resemble filamentous cyanobacteria that the researchers found wrapped around the rhizoids of the decaying M. polymorpha.
"We were really excited when we saw how similar the ultrastructure of our liverwort rhizoid walls was to images of Prototaxites tubes published in 1976 by Rudy Schmid," Graham said.
In their investigations into the nutritional requirements of M. polymorpha, Graham and her colleagues found that the growth of M. polymorpha in a glucose-based medium was approximately 13 times that seen when the liverwort was grown in a medium without glucose. Stable carbon isotope analyses indicated that less than 20% of the carbon in the glucose-grown liverwort came from the atmosphere. The stable carbon isotope values obtained from M. polymorpha grown with varying amounts of cyanobacteria present span the range of values reported for Prototaxites fossils. Taken together, these results demonstrate that the liverworts have a capacity for mixotrophic nutrition when glucose is present and that mixotrophy and/or the presence of cyanobacteria could be responsible for the stable carbon isotope values obtained from Prototaxites.
Graham and her colleagues' results demonstrate that liverworts were important components of Devonian ecosystems. Their results support previous hypotheses that microbial associations and mixotrophy are ancient plant traits, rather than ones that have evolved recently.
More information: The full article in the link mentioned is available for no charge for 30 days at http://www.amjbot.org/cgi/content/full/97/2/268
Monday, February 22, 2010
Scientists from Glasgow, Oxford and the United States have identified fossil evidence which shows the fish existed between 66 and 172 million years ago.
They believe it may be a "missing piece in the evolutionary story of fish, mammals and ocean ecosystems".
The findings of the research are published in the journal, Science.
The international team which carried out the study included academics from Glasgow and Oxford Universities, DePaul University in Chicago, Fort Hays University in Kansas and the University of Kansas.
The project began in Glasgow, with a review of the remains of the giant Jurassic fish Leedsichthys, in conjunction with the excavation of a new specimen of this creature in Peterborough.
Scientists viewed Leedsichthys as an isolated example of a giant filter feeder in the oceans during the age of dinosaurs.
But there was a gap in the fossil record between it and the first appearance of modern filter-feeders, some 100 million years later.
Dr Jeff Liston, from Glasgow University, ran the excavation in Peterborough and found the new specimen to be an anomaly.
"The breakthrough came when we discovered additional fossils, similar to Leedsichthys, but from much younger rocks," he said.
"These specimens indicated that there were giant filter-feeding fishes for much longer than we thought.
"We then started to go back to museum collections, and we began finding suspension-feeding fish fossils from all round the world, often unstudied or misidentified."
Several of the most important new fossils - all from the same extinct bony fish family as Leedsichthys - came from sites in Kansas.
Other remains originated as far afield as Dorset and Kent in the UK, and in Japan.
Dr Liston added: "The fact that creatures of this kind were missing from the fossil record for over 100 million years seemed peculiar.
"What we have demonstrated here is that a long dynasty of giant bony fish filled this space in time for more than 100 million years.
"It was only after these fish vanished from the ecosystem that mammals and cartilaginous fish such as manta rays, basking sharks, whale sharks began to adapt to that ecological role."
Dr Liston said the findings had "implications for our understanding of biological productivity in modern oceans, and how that productivity has changed over time".
One of the best preserved Kansas specimens had previously been interpreted as similar to a fanged predatory swordfish.
When members of the team began to clean the specimen, they found a toothless gaping mouth, with an extensive network of thin elongate bony plates to extract huge quantities of microscopic plankton.
The team named this four to five metre-long fish Bonnerichthys, in honour of the Kansas family who discovered the fossil.