Ceres Excerpt from cnet.com It's a real-life mystery cliffhanger. We've come up with a list of possible reasons a large crater on the biggest object in the asteroid belt looks lit up like a Christmas tree. We could be approachin...
Tag: plenty (page 2 of 5)
A group of scientists at Cornell University believe that Titan, one of Saturn’s moons, may be a haven of life. However, it would not be in the form that human beings know. Methane based life forms might live on Titan, the scientists have said, after they created a model of an oxygen free life form which would be able to thrive in the icy, unforgiving conditions that Saturn’s moon offers.
They studied the various forms of cell membranes that exist on Earth, which are made up of lipid bi-layer structures. The Cornell scientists said such membranes would not be able to exist in environments where liquid water could not be present, according to Design and Trend.
Titan has plenty of lakes filled with methane, so that means it might not be habitable in the way that scientists had formerly described habitability. However, Dr. James Stevenson and his team thinks that contrarily structured membranes could offer the foundation for life to exist on Saturn’s moon. The model they created used organic nitrogen mixtures, so that the new structure could easily function on Titan in the richness of the methane that exists in liquid form there.
Titan
Dr. Stevenson said it was Isaac Asimov, the celebrated sci-fi writer, who first gave the rudimentary inspiration for the idea in the paper he penned, which was called the Not as We Know It essay. It was written about non-water-based life forms. Because Saturn’s moon is the only known celestial form in the solar system to have naturally occurring fluids on its surface, except for the Earth, the group of scientists believe it to be a possible perfect foundation for life forms to develop.
Dr. Paulette Clancy, who has helped lead the group, constructed an “azotosome.” It is comparable in name origin to liposome which comes from the Greek words lipos and soma. An azotosome comes from the French word for nitrogen. Therefore, the word is describing a nitrogen body.
Instead of trying to find alien life within the area that surrounds the Sun where water exists in liquid form, the group decided to try and imagine a new kind of cell, grounded on methane instead of water. Clancy and the team were dumbfounded to find that this new projected model presented an alike stability to the cell membranes already here on Earth.
Dr. Clancy seemed very anxious to carry on the group’s work and find out how such compounds would truly work in the methane atmosphere. Dr. Jonathan Lunine, who is a top expert in Titan and also one of the co-authors of the study, thinks that it might be possible in the future to in fact test these theories by actually examing organic material from Saturn’s moon. In the years to come, Dr. Lunine stated that probes might be sent to Titan to gather the needed material by floating down on the methane seas of the moon of Saturn.
The group discovered a compound they named acrylonitrile azotosome, which appeared to show good stability. It had a strong barricade to decomposition, and a suppleness that was similar to phospholipid membranes that exist on Earth. Acrylonitrile is a poisonous, colorless, liquid organic compound that is used in the production of acrylic fibers and thermoplastics and it is present in Titan’s atmosphere as well.
They have written up about their discovery and what they believe to be possible. The scientists’ paper was printed up in the journal Science Advances on Friday.
Excerpt from mashable.comOnly 100 people are still competing for four seats on a one-way trip to Mars advertised by Dutch nonprofit Mars One.In its latest round of cuts, the foundation cut its applicant pool from 660 to 100 finalists on Tuesday. More ...
“The ingredients for life are plentiful, and we now know that habitable environments are plentiful,” says Professor Charley Lineweaver, a down-under astrophysicist.
Lineweaver and PhD student Tim Bovaird worked this out by reviewing the data on exoplanets discovered by the famed Kepler planet-hunter space scope. Kepler naturally tends to find exoplanets which orbit close to their parent suns, as it detects them by the changes in light they make by passing in front of the star. As a result, most Kepler exoplanets are too hot for liquid water to be present on their surfaces, which makes them comparatively boring.
Good planets in the "goldilocks" zone which is neither too hot nor too cold are much harder to detect with Kepler, which is a shame as these are the planets which might be home to alien life - or alternatively, home one day to transplanted Earth life including human colonists, once we've cracked that pesky interstellar travel problem.
However there exists a thing called the Titius-Bode relation - aka Bode's Law - which can be used, once you know where some inner planets are, to predict where ones further out will be found.
Assuming Bode's Law works for other suns as it does here, and inputting the positions of known inner exoplanets found by Kepler, Lineweaver and Bovaird found that on average a star in our galaxy has two planets in its potentially-habitable zone.
That doesn't mean there are habitable or inhabited planets at every star, of course. Even here in our solar system, apparently lifeless (and not very habitable) Mars is in the habitable zone.
Even so, there are an awful lot of planets in the galaxy, so some at least ought to have life on them, and in some cases this life ought to have achieved a detectable civilisation. Prof Lineweaver admits that the total lack of any sign of this is a bit of a puzzler.
"The universe is not teeming with aliens with human-like intelligence that can build radio telescopes and space ships," admits the prof. "Otherwise we would have seen or heard from them.
“It could be that there is some other bottleneck for the emergence of life that we haven’t worked out yet. Or intelligent civilisations evolve, but then self-destruct.”
Of course, humans - some approximations of which have been around for some hundreds of thousands of years, perhaps - have only had civilisation of any kind in any location for a few thousand of those years. Our civilisation has only risen to levels where it could be detectable across interstellar distances very recently.
There may be many planets out there inhabited by intelligent aliens who either have no civilisation at all, or only primitive civilisation. There may be quite a few who have reached or passed the stage of emitting noticeable amounts of radio or other telltale signs, but those emissions either will not reach us for hundreds of thousands of years - or went past long ago.
It would seem reasonable to suspect that there are multitudes of worlds out there where life exists in plenty but has never become intelligent, as Earth life was for millions of years before early humans began using tools really quite recently.
But the numbers are still such that the apparent absence of star-travelling aliens could make you worry about the viability of technological civilisation if, like Professor Lineweaver, you learn your astrophysics out of textbooks and lectures (and publish your research, as we see here, in hefty boffinry journals like the Monthly Notices of the Royal Astronomical Society).
But if movies, speculofictive novels and TV have taught us anything here on the Reg alien life desk, it is that in fact the galaxy is swarming with star-travelling aliens (and/or humans taken secretly from planet Earth for mysterious purposes in the past, or perhaps humans from somewhere else etc). The reason we don't know about them is that they don't want us to.
Excerpt from seattletimes.com
A decision to list the captive orca Lolita for federal protection is expected to set the stage for a lawsuit from advocates seeking the whale’s release.
By Hal Bernton
Seattle Times staff reporter
The National Oceanic and Atmospheric Administration (NOAA) announced Wednesday the decision to list Lolita as part of the southern resident killer whales of Puget Sound, which already are considered endangered under the federal act.
Whale activists, who petitioned for this status, have long campaigned for Lolita’s return to Puget Sound. They hope the listing will provide a stronger legal case to release Lolita than did a previous lawsuit that centered on alleged violations of the federal Animal Welfare Act.
“This gives leverage under a much stronger law,” said Howard Garrett of the Whidbey Island based Orca Network, which hopes a San Juan Island cove will one day serve as the site for Lolita to re-enter the wild.
NOAA Fisheries officials on Wednesday described their decision in narrow terms, which set no broader precedents. It does not address whether Lolita should be released from the Seaquarium.
“This is a listing decision,” said Will Stelle, the NOAA Fisheries regional administrator for the West Coast. “It is not a decision to free Lolita.”
Aquarium officials have repeatedly said they have no intention of releasing the orca.
“Lolita has been part of the Miami Seaquarium family for 44 years,” said Andrew Hertz, Seaquarium general manager, in a statement.
“Lolita is healthy and thriving in her home where she shares habitat with Pacific white-sided dolphins. There is no scientific evidence that ... Lolita could survive in a sea pen or the open waters of the Pacific Northwest, and we are not willing to treat her life as an experiment.”
Orcas, also known as killer whales, are found in many of the world’s oceans. The southern resident population, which spends several months each year in Puget Sound, is the only group listed in the U.S. under the Endangered Species.
The three pods in the population were reduced by captures by marine parks between 1965 and 1975, NOAA says. Among them was a roundup in Penn Cove where seven whales were captured, including Lolita.
The southern resident pods now number fewer than 80. Possible causes for the decline are reduced prey, pollutants that could cause reproductive problems and oil spills, according to NOAA Fisheries.
Under the Endangered Species Act, it is illegal to cause a “take” of a protected orca, which includes harming or harassing them.
Wednesday, NOAA officials said holding an animal captive, in and of itself, does not constitute a take.
Orca activists are expected to argue in their lawsuit that Lolita's cramped conditions result in a prohibited take.
There is “rising public scorn for the whole idea of performing orcas,” said Garrett, who hopes Seaquarium will decide to release Lolita without a court order.
But NOAA officials still have concerns about releasing captive whales, and any plan to move or release Lolita would require “rigorous scientific review,” the agency said in a statement.
The concerns include the possibility of disease transmission, the ability of a newly released orca to find food and behavior patterns from captivity that could impact wild whales.
NOAA said previous attempts to release captive orcas and dolphins have often been unsuccessful and some have ended in death.
Garrett said the plan for Lolita calls for her to be taken to a netted area of the cove, which could be enlarged later. She would be accompanied by familiar trainers who could “trust and reassure her every bit of the way,” he said.
The controversy over releasing captive whales has been heightened by the experience of Keiko, a captive orca that starred in the 1993 movie “Free Willy,” about a boy who pushed for the release of a whale.
In 1998, Keiko was brought back to his native waters off Iceland to reintroduce him to life in the wild. That effort ended in 2003 when he died in a Norwegian fjord.
Garrett, who visited Keiko in Iceland in 1999, said he was impressed by the reintroduction effort, and that there was plenty of evidence that Keiko was able to catch fish on his own.
“The naysayers predicted that as soon as he got into the (Icelandic) waters he would die, and wild orcas would kill him,” Garrett said. “He proved that 180-degrees wrong. He loved it.”
Mark Simmons, who for two years served as director of animal husbandry for the Keiko-release effort, has a different view. He says Keiko never was able to forage for fish on his own, and that he continued to seek out human contact at every opportunity.
Simmons wrote a book called “Killing Keiko,” that accuses the release effort of leading to a long slow death for the orca, which he says lacked food and then succumbed to an infection.
“It’s not really the fact that Keiko died, but how he died,” Garrett said Wednesday.
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| Various features on a smooth part of the comet's surface in the region named Imhotep. |
Excerpt from wired.com
The Rosetta spacecraft has been studying comet 67P/Churyumov-Gerasimenko up close since August, collecting data of unprecedented detail and taking pictures of a starkly beautiful comet-scape. While the Philae lander has enjoyed much of the spotlight—partly thanks to its now-famous triple landing—Rosetta has been making plenty of its own discoveries.
One of the biggest came last month, when scientists found that the chemical signature of the comet’s water is nothing like that on Earth, contradicting the theory that crashing comets supplied our planet with water. Comet 67P belongs to the Jupiter family of comets, and the findings also imply that these kinds of comets were formed at a wider range of distances from the sun than previously thought, says Michael A’Hearn, a planetary scientist at the University of Maryland, College Park, and member of the Rosetta science team.
Today, scientists have published the first big set of results from Rosetta in a slew of papers in the journal Science. The results include measurements and analyses of the comet’s shape, structure, surface, and the surrounding dust and gas particles. Here are just a few of the amazing things they’ve discovered about Rosetta’s comet so far:
The surface is fantastically weird
The comet has quite the textured landscape, covered with steep cliffs, boulders, weird bumps, cracks, pits, and smooth terrain. There are fractures of all sizes, including one that’s several yards wide and stretches for more than half a mile along the comet’s neck. Researchers don’t yet know what caused these cracks. The pits have steep sides and flat bottoms, ranging in size from a few tens to hundreds of feet wide. Jets of dust shoot out from some of the pits, suggesting that the ejection of material formed these features. Another strange feature is what scientists are calling goosebumps—weird bumpy patches found particularly on steep slopes.
While other features such as pits and fractures range in sizes, all of the goosebumps are about 10 feet wide. No one knows what kind of process would make the bumps, but whatever it is could have played an important part in the comet’s formation. It may be breezy Rosetta spotted dune- and ripple-like patterns,wind tails behind rocks, and even moats surrounding rocks, suggesting that a light breeze may blow dust along the surface. Such a gentle wind would have to come from gases leaking from below.
Because of the extremely low gravity on the comet, it wouldn’t take a strong gust to blow things around. It may have formed from two separate pieces Or not. The most distinct feature of comet 67P is its odd, two-lobed shape, which resembles a duck. Although scientists have seen this lobed structure in other comets before, namely Borrelly and Hartley 2, none are as pronounced as comet 67P’s. Borrelly and Hartley 2 look more like elongated potatoes while 67P has a clearly defined head and body. The strange shape suggests the comet was once two separate pieces called cometesimals—what are now the duck’s head and body—that stuck together.
The other possibility is that erosion ate away the parts around the neck. Preliminary evidence points to the first hypothesis.
“Probably most of us on the OSIRIS team lean toward thinking it was two cometesimals,” A’Hearn said. (OSIRIS is one of Rosetta’s imaging instruments.) But the scientists won’t have conclusive evidence until they study the comet in more detail. For example, they now see layering along the neck—if erosion carved out the comet’s duck shape, they should find the same same layering pattern continuing onto the other side of the neck.
Black, with a tinge of red
Even Rosetta’s color pictures show a grayish comet, but if you were to see it in person, you would see a pitch-black chunk of dust and ice, as it reflects only six percent of incoming light. By comparison, the moon reflects 12 percent of incoming light and Earth reflects 31 percent. But comet 67P’s not completely black, as it has a hint of red. Water, water, nowhere? The comet’s covered in opaque, organic compounds. Although comet 67P is undoubtedly icy, it hardly shows any water ice on its surface at all.
Which isn’t too surprising, as comets Tempel 1 and Hartley 2 didn’t have much ice on their surfaces either, A’Hearn says. Rosetta has yet to see sunlight reach every side of the comet yet, so there may still be some icy patches hidden from view. But, researchers do see the comet spraying water vapor into space, which means water ice likely lies just beneath the surface. The ice doesn’t have to be more than a centimeter deep to be invisible from the infrared instruments that detect the ice. Indeed, the data from Philae’s first bounce suggested that there’s a hard layer of ice beneath 4 to 8 inches of dust.
This duck floats
If you could find a big enough pond, that is. Like other known comets, the density of comet 67P is about half that of water ice. Initial measurements reveal that it’s also very porous—as much as 80 percent of it may be empty space. Rosetta has found depressions, which may have formed when the surface collapsed over particularly porous material underneath.
Different from every angle
As the comet nears the sun, it heats up, and ices and other volatile chemicals sublimate, spraying gases into space. So far, the most prominent gases that have been ejected are water vapor, carbon dioxide, and carbon monoxide. They spew out in different amounts from different parts of the comet. In particular, a lot of the water has been observed gushing out from the neck.The comet will continue to get more active as it reaches its closest approach to the sun in mid-August. It will burst with stronger jets of gas and dust, and maybe even blast off chunks of itself. If the comet is this interesting now, A’Hearn says, just wait until it gets to its nearest point to the sun, when it’s just 1.29 times farther from the sun than Earth is.
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Gazing at galaxy clusters like Abell 2218, it's hard to imagine how we fit into the cosmos. Evolution can help with that, says Bill Nye. Photograph by NASA, ESA, and Johan Richard (Caltech, USA) |
Darwin's theory explains so much of the world, from bumblebees to human origins, says the Science Guy.
Excerpt from
By Jane J. Lee
The experience prompted the celebrity science educator to write a "primer" on the theory of evolution called Undeniable: Evolution and the Science of Creation. In his new book, Nye delights in how this fundamental discovery helps to unlock the mysteries of everything from bumblebees to human origins to our place in the universe.
Who do you hope will read this book?
Grown-ups who have an interest in the world around them, people coming of age who have an interest in science, people who still want to know how the world works.
This is the big concern of mine with respect to the organization Answers in Genesis and Ken Ham and all those guys: their relentless, built-in attempts to indoctrinate a generation of science students on a worldview that is obviously wrong.
I worry about these kids—they're part of my society. We can't raise a generation of students who don't understand the fundamental idea in all of life science, any more than you want to raise a generation of kids who don't understand chemistry or physics or arithmetic.
How and when did you first encounter creationism?
About 20 years ago. I was a member of the Northwest Skeptics, which is the Seattle-based skeptics organization. We met people who insisted that the Earth was 6,000 years old. The inanity took my breath away. When you understand anything about astronomy or have just a rudimentary understanding of radioactivity, the Earth is patently not 6,000 years old. It's silly.
It's been said that a good way of convincing people of something is to appeal to their emotions. What do you think?
That's my business! In the book, I purposely spend a lot of time in the first person. The reason is, we find stories compelling. Stories are how we remember things, how we organize things.
By telling a story in the first person, it's hard to dismiss. If I say, "I remember the time I met Ivan the gorilla," it's really difficult for the listener or reader to go, "No, you don't!"
When you say, "I feel," it's really hard for the reader to say, "No, you don't." Yes, I do. I did a lot of that in the book...
A fascination with bees and flight drew a young Bill Nye into the world of science and evolution.
Photograph by Mark W Moffett, National Geographic
One of the most fundamental ideas in explaining life on Earth is the theory of evolution, says Nye.
Photograph by NASA Earth Observatory
Excerpt from space.com
Most people have two eyes. Humans evolved to use them together (not all animals do). People form a continuous, stereoscopic panorama movie of the world within in their minds. With your two eyes tilted upward on a clear night, there's nothing standing between you and the universe. The easiest way to enhance your enjoyment of the night sky is to paint your brain with two channels of stronger starlight with a pair of binoculars. Even if you live in — or near — a large, light-polluted city, you may be surprised at how much astronomical detail you'll see through the right binoculars!
Our editors have looked at the spectrum of current binocular offerings. Thanks to computer-aided design and manufacturing, there have never been more high-quality choices at reasonable prices. Sadly, there's also a bunch of junk out there masquerading as fine stargazing instrumentation. We've selected a few that we think will work for most skywatchers.
There was a lot to consider: magnification versus mass, field of view, prism type, optical quality ("sharpness"), light transmission, age of the user (to match "exit pupil" size, which changes as we grow older), shock resistance, waterproofing and more.
The best binoculars for you
"Small" astronomy binoculars would probably be considered "medium" for bird watching, sports observation and other terrestrial purposes. This comes about as a consequence of optics (prism type and objective size, mostly). "Large" binoculars are difficult to use for terrestrial applications and have a narrow field of view. They begin to approach telescope quality in magnification, resolution and optical characteristics.Most of our Editors' Choicesfor stargazing binoculars here are under $300. You can pay more than 10 times that for enormous binocular telescopes used by elite enthusiasts on special mounts! You'll also pay more for ruggedized ("mil spec," or military standard) binoculars, many of which suspend their prisms on shock mounts to keep the optics in precise alignment.
Also, our Editors' Choices use Porro prism optics. Compact binoculars usually employ "roof" prisms, which can be cast more cheaply, but whose quality can vary widely. [There's much more about Porro prisms in our Buyer's Guide.]
We think your needs are best served by reviewing in three categories.
- Small, highly portable binoculars can be hand-held for viewing ease.
- Medium binoculars offer higher powers of magnification, but still can be hand-held, if firmly braced.
- Large binoculars have bigger "objective" lenses but must be mounted on a tripod or counterweighted arm for stability.
Best Small Binoculars
Editor's Choice: Oberwerk Mariner 8x40 (Cost: $150)
Runner-Up: Celestron Cometron 7x50 (Cost: $30)
Honorable Mention: Swarovski Habicht 8x30 (Cost: $1,050)
Honorable Mention: Nikon Aculon 7x50 (Cost: $110)
Nikon's legendary optical quality and the large, 7mm exit pupil diameter make these appropriate as a gift for younger skywatchers.Best Medium Binoculars
Editor's Choice: Celestron SkyMaster 8x56 (Cost: $210)
Runner-Up: Oberwerk Ultra 15x70 (Cost: $380)
Honorable Mention: Vixen Ascot 10x50 (Cost:$165)
These quirky binoculars present you with an extremely wide field. But they are not crash-worthy – don't drop them in the dark – nor are they waterproof, and the focus knob is not conveniently located. So care is needed if you opt for these Vixen optics.Best Large Binoculars
Runner-Up: Orion Astronomy 20x80 (Cost: $150)
These big Orions distinguish themselves by price point; they're an excellent value. You could pay 10 times more for the comparably sized Steiners Military Observer 20x80 binoculars! Yes, the Orions are more delicate, a bit less bright and not quite as sharp. But they do offer amazingly high contrast; you'll catch significant detail in galaxies, comets and other "fuzzies." Unusually among such big rigs, the Astronomy 20x80 uses a center focus ring and one "diopter" (rather than independently focusing oculars); if you’re graduating from smaller binoculars, which commonly use that approach, this may be a comfort. These binoculars are almost lightweight enough to hold them by hand. But don't do that, at least not for long periods. And don't drop them. They will go out of alignment if handled roughly. Honorable Mention: Barska Cosmos 25x100 (Cost: $230)
They are not pretty, but you're in the dark, right? Built around a tripod-mountable truss tube, these Barskas equilibrate to temperature quickly and give you decent viewing at rational cost. They make for a cheaper version of our Editors' Choice Celestron SkyMasters.Honorable Mention: Steiner Observer 20x80 (Cost: $1,500)
Not at all a practical cost choice for a beginning stargazer, but you can dream, can't you? These Steiner binoculars are essentially military optics "plowshared" for peaceful celestial observing.Why we chose NOT to review certain types
Image stabilized?
Binoculars with active internal image stabilization are a growing breed. Most use battery-powered gyroscope/accelerometer-driven dynamic optical elements. We have left this type out of our evaluation because they are highly specialized and pricey ($1,250 and up). But if you are considering active stabilization, you can apply the same judgment methods detailed in our Buyer's Guide.Comes with a camera?
A few binoculars are sold with built-in cameras. That seems like a good idea. But it isn't, at least not for skywatching. Other than Earth's moon, objects in the night sky are stingy with their photons. It takes a lengthy, rock-steady time exposure to collect enough light for a respectable image. By all means, consider these binocular-camera combos for snapping Facebook shots of little Jenny on the soccer field. But stay away from them for astronomy.Mega monster-sized?
Take your new binoculars out under the night sky on clear nights, and you will fall in love with the universe. You will crave more ancient light from those distant suns. That may translate into a strong desire for bigger stereo-light buckets.Caution: The next level up is a quantum jump of at least one financial order of magnitude. But if you have the disposable income and frequent access to dark skies, you may want to go REALLY big. Binocular telescopes in this class can feature interchangeable matching eyepieces, individually focusing oculars, more than 30x magnification and sturdy special-purpose tripods. Amateurs using these elite-level stereoscopes have discovered several prominent comets.
Enjoy your universe
If you are new to lens-assisted stargazing, you'll find excellent enhanced views among the binocular choices above. To get in deeper and to understand how we picked the ones we did, jump to our Buyer's Guide: How to Choose Binoculars for Sky Watching.You have just taken the first step to lighting up your brain with star fire. May the photons be with you. Always.
Skywatching Events 2015
Once you have your new binoculars, it's time to take them for a spin. This year intrepid stargazers will have plenty of good opportunities to use new gear.On March 20, for example, the sun will go through a total solar eclipse. You can check out the celestial sight using the right sun-blocking filters for binoculars, but NEVER look at the sun directly, even during a solar eclipse. It's important to find the proper filters in order to observe the rare cosmic show.
Observers can also take a look at the craggy face of the moon during a lunar eclipse on April 4. Stargazers using binoculars should be able to pick out some details not usually seen by the naked eye when looking at Earth's natural satellite.
Skywatchers should also peek out from behind the binoculars for a chance to see a series of annual meteor showers throughout the year.
Excerpt from time.com
It wasn't just an asteroid
At the start of the 1980s, the question of what forced dinosaurs and huge numbers of other creatures to become extinct 65 million years ago was still a mystery. By the decade’s end, that mystery was solved: a comet or asteroid had slammed into Earth, throwing so much sun-blocking dust into the air that the planet plunged into a deep-freeze. The discovery of a massive impact crater off the coast of Mexico, of just the right age, pretty much sealed the deal in most scientists’ minds.But a second global-scale catastrophe was happening at much the same time: a series of ongoing volcanic eruptions that dwarf anything humans have ever seen. They were so unimaginably powerful that they left nearly 200,000 square miles (518,000 sq. km) of what’s now India buried in volcanic basalt up to a mile and a half thick. And the gases and particulate matter spewed out by those eruptions, argue at least some scientists, could have played a big role in the dinosaurs’ doom as well.
How big a role, however, depends on exactly when the eruptions began and how long they lasted, and a new report in Science goes a long way toward answering that question. “We can now say with confidence,” says Blair Schoene, a Princeton geologist and lead author of the paper, “that the eruptions started 250,000 years before the extinction event, and lasted for a total of 750,000 years.” And that, he says, strengthens the idea that the eruptions could have contributed to the mass extinction of multiple species.
Schoene and his co-authors don’t claim volcanoes alone wiped out the dinosaurs; only that they changed the climate enough to put ecosystems under stress, setting them up for the final blow. “We don’t know the exact mechanism,” he admits. Volcanoes emit carbon dioxide, which could have triggered an intense burst of global warming, but they also emit sulfur dioxide, which could have caused global cooling. “What we do know,” Schoene says, “is that earlier mass extinctions were caused by volcanic eruptions alone.” The new dates, he and his co-authors believe, will help scientists understand what role these volcanoes played in the dinosaurs’ demise.
If there was such a role, that is, and despite this new analysis, plenty of paleontologists still doubt it seriously. The dating of the eruptions, based on widely accepted uranium-lead measurement techniques, is not an issue, says Brian Huber, of the Smithsonian Institution. “That part of the science is great,” he says. “It moves things forward.”
And those data, Huber says, make it clear that the extinction rate for the 250,000 years leading up to the asteroid impact wasn’t especially large. Then, at the time of the impact: whammo. The idea that volcanoes played a significant role in this extinction event keeps coming up every so often, and in Huber’s view, “the argument has gotten very tiresome. I no longer feel the need to put any energy into it. It’s from a minority arguing against overwhelming evidence.”
Excerpt from theglobeandmail.com
By Ivan Semeniuk
Half a billion kilometres from Earth and 10 years into its remarkable journey, a small robot is about to plunge into space history.
Pending a final green light from mission controllers on Tuesday night, the robot – nicknamed Philae (fee-lay) – will detach from its mother ship and try to hook itself onto one of the most challenging and mysterious objects in the solar system.
It’s a high-risk manoeuvre with plenty of unknowns. But if it works, then the probe will be able to show us what no one has ever experienced: what it’s like to stand on the surface of a comet.
“Comets are new territory,” said Ralf Gellert, a professor of physics at the University of Guelph. “There could be some big surprises.”
Prof. Gellert should know. Fifteen years ago, he helped build one of the instruments on the dishwasher-size lander that will reveal the comet’s composition. No such direct measurement has been made before. Even designing how the instrument should work was fraught with challenges since there was so little known about what kind of surface the lander might find itself on.
“Is it an ice ball with rock and trace metals, or a rock ball with ice on it … or ice below the surface? We didn’t know,” he said.
And scientists still don’t.
When the European Space Agency launched the Rosetta mission in 2004, the mission’s target – Comet Churyumov-Gerasimenko – was little more than a fuzzy blip in astronomers’ telescopes. But Rosetta just arrived in August and it’s been in orbit around the comet since then.
What was assumed to be a single, homogeneous lump of ice and rock has turned out to be a bizarre-looking object in two parts, arranged a bit like the head and body of a rubber duck. By October, scientists had zeroed in on the head portion, which is four kilometres across at its widest point, and settled on a landing site.
Remote sensing data from Rosetta suggest that the comet is quite porous, with a surface that is as black as coal and somewhat warmer than expected. In other words, Philae will probably not be landing on skating-rink-hard ice. Yet, whether the surface will be crusty like a roadside snowbank, fluffy like cigarette ash, or something else entirely is anyone’s guess.
And while scientists and engineers say they’ve done everything they can think of to maximize the lander’s chance of success, they acknowledge it’s entirely possible that Philae will encounter something it can’t handle and smash to bits or sink into oblivion.
Yet the landing is more than a daring jaunt to see what has never been seen before. Comets are also among the most primitive bodies in the solar system. Each one is an amalgam of ice and rock that has been around since Earth and its sister planets formed billions of years ago. In a sense, comets are the leftovers of that process – primordial fossils from the birth of the solar system.
The instrument Prof. Gellert worked on, known as the alpha particle X-ray spectrometer (APXS), will help illuminate this early period by making precise measurements of the comet’s elemental ingredients.
It is carried on a robot arm that will place a radioactive source near the comet’s surface. The particles and X-rays the comet material gives off as a result of this exposure will provide detailed information about what chemical elements the comet contains. This will be augmented by another experiment designed to drill and extract a comet sample for analysis inside the lander.
Prof. Gellert, who has also been closely involved in NASA’s Mars rover missions, said Rosetta’s long timeline and the many unknowns related to the comet makes this week’s landing a trickier proposition than landing on Mars – but also a tremendously exciting one.
“I think it’s a matter of hope for the best and see what happens.”
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| An artist's rendition of the amphibious Cartorhynchus lenticarpus. (Stefano Broccoli) |
My absolute favorite moment of the study though had to be the team's conclusion that the foot and a half long green amphibian "probably had a happy life". I could see now a room full of white lab coats concurring with one another. "Yes yes, happy indeed. I concur." A young lab technician then sheepishly speaks up. "I must disagree sirs. My research shows its not easy being green." "Oh yes, yes," the group of senior scientists now concede. "Indeed, it's not easy being green."
Motani's statement that his team now hopes to find the preceding evolutionary ancestor to Cartorhynchus lenticarpus as their next major breakthrough is the part of this report that I can't get out of my mind. What would the odds be that this small group of researchers not only find one crucial missing link, but will also discover the very next missing piece of the long evolutionary puzzle chain, evidence countless archeologists, scientists and researchers have been, for centuries, turning over stones in search of. Something smells fishy here, and it isn't the great, great, great grandfather of Kermit the Frog.
Greg Giles
Excerpts from the washingtonpost.com article by Rachel Feltman:
Researchers report that they've found the missing link between an ancient aquatic predator and its ancestors on land. Ichthyosaurs, the dolphin-like reptiles that lived in the sea during the time of the dinosaurs, evolved from terrestrial creatures that made their way back into the water over time.
But the fossil record for the lineage has been spotty, without a clear link between land-based reptiles and the aquatic ichthyosaurs scientists know came after. Now, researchers report in Nature that they've found that link — an amphibious ancestor of the swimming ichthyosaurs named Cartorhynchus lenticarpus.
"Many creationists have tried to portray ichthyosaurs as being contrary to evolution," said lead author Ryosuke Motani, a professor of earth and planetary sciences at the University of California Davis. "We knew based on their bone structure that they were reptiles, and that their ancestors lived on land at some time, but they were fully adapted to life in the water. So creationists would say, well, they couldn't have evolved from those reptiles, because where's the link?"
Now the gap has been filled, he said.
The creature is about a foot and a half long and lived 248 million years ago.
"Initially I was really puzzled by this fossil," Motani said. "I could tell it was related [to ichthyosaurs], but I didn't know how to place it. It took me about a year before I was sure I had no doubts."
One of the most important differences between this new ichthyosaur and its supposed descendants comes down to being big boned: When other vertebrates have evolved from land to sea living, they've gone through stages where they're amphibious and heavy. Their thick bones probably allowed them to fight the power of strong coastal waves and stay grounded in shallow waters. Sure enough, this new fossil has much thicker bones than previously examined ichthyosaurs.
"This animal probably had a happy life. It was in the tropics, and it was probably a bottom feeder that fed on soft-bodied things like squid and animals like shrimp," Motani said. "And for a predator like that to exist, there has to be plenty of prey. This was probably one of the first predators to appear after that extinction."
This single fossil hasn't revealed all of the ichthyosaurs' secrets. Motani hopes to find the preceding evolutionary ancestor next — one that was also amphibious, but spent slightly more of its time on land. "We're looking for that one now," Motani said.
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