We’re posting several of our most popular pieces from the past few months for your enjoyment this Holiday Season.
In a couple of weeks we hope to go live as a new iPhone app. We’ll announce to all once we’re approved.
Our thanks for making the past year at The Daily Galaxy such a rewarding adventure!
It may be getting into headlines more often for its cellphones (especially the never-ending Corby range) but Samsung is busy in other fields too. It recently gave us a glimpse of its latest digital camera – the CL80 and we were not just intrigued – heck, we were downright impressed.
The reason for our jaws doing the dropping act was not just gravity. Or even the specs on the new Sammy clicker. All right, 14 megapixels, 7x optical zoom, 31 mm wide angle lens, 720 dp HD recording and HDMI connectivity are not to be sneezed at, but at the most, they would elicit a raise of the ‘umble eyebrow. What sent ours scurrying into our scalps was the fact that the device comes with a bigger than usual 3.7 inch display. And it ain’t an ordinary display – it is AMOLED. It is a touchscreen. And a capacitive (read “iPhone type”) one at that. With haptic feedback!
And we are not through yet. The camera has support for Wi-Fi and comes with integrated Facebook, Flickr, PhotoBox and Picasa and YouTube access. In simple terms, this means that if you happen to be in a hot spot you can directly upload your videos and pictures to these websites – no computer required. Now, that is the way to hit back at those sissy camera phones and their click-and-upload-instantly advantage.
All of which is enough to convince us that this is no ordinary shooter that Sammy has up its ample product sleeves, even though the interface seems a tad iffy (was never convinced by touchscreen camera displays, truth be told). All that remains to be known is when will it hit the market. January, we are told and as for the price, ah, that was sealed lips territory. Analysts reckon it will be in and around USD 450-500 territory.
And when it does hit the market, we bet many people will wonder: is this what digicams will become? Aye, we say. Just throw in GPS for some geo-tagging and (dreamily) an inbuilt 3G card and we will dump our cameraphones instanter.
Similar Posts:
We’re posting several of our most popular pieces from the past few months for your enjoyment this Holiday Season.
In a couple of week’s we hope to go live as a new iPhone app. We’ll announce to all once we’re approved.
Our thanks for making the past year at The Daily Galaxy such a rewarding adventure!
We’re posting several of our most popular pieces from the past few months for your enjoyment this Holiday Season.
In a couple of week’s we hope to go live as a new iPhone app. We’ll announce to all once we’re approved.
Our thanks for making the past year at The Daily Galaxy such a rewarding adventure!
“For me the most astonishing evidence is the
way that one man-made environmental impact - the ozone hole - has
shielded most of Antarctica from another - global warming,” reported
John Turner of the BAS team.
“For me the most astonishing evidence is the
way that one man-made environmental impact - the ozone hole - has
shielded most of Antarctica from another - global warming. There is no
doubt that our world is changing and human activity is accelerating
global change. This review is a major step forward in making sure that
the latest and best evidence is available in one place,” said Turner.
“It sets the scene for future Antarctic Research and provides the
knowledge that we all need to help us live with environmental change.”
Research cruise leader Dr. David Barnes of British Antarctic Survey said, “Few people realize just how rich in biodiversity the Southern Ocean is – even a single trawl can reveal a fascinating array of weird and wonderful creatures as would be seen on a coral reef.”
Casey Kazan
Image Credit: Icefish BAS.
New evidence has been discovered by an international team led by astronomers from the National Science Foundation's Arecibo Observatory and from Cardiff University in the United Kingdom that VIRGOHI 21, a mysterious cloud of hydrogen in the Virgo Cluster 50 million light-years from the Earth, is a Dark Galaxy, emitting no starlight. Their results not only indicate the presence of a dark galaxy but also explain the long-standing mystery of its strangely stretched neighbour. Skeptics of the dark-matter interpretation argue that VIRGOHI21 is simply a tidal tail of the nearby galaxy NGC 4254.
The observations, made with the Westerbork Synthesis Radio Telescope in the Netherlands, show that the hydrogen gas in VIRGOHI 21 appears to be rotating, suggesting a dark galaxy with over ten billion times the mass of the Sun. Only one percent of this mass has been detected as neutral hydrogen – the rest appears to be dark matter.
The results may also solve a long-standing puzzle about nearby galaxy NGC 4254 -a lopsided object, with one spiral arm much larger than the rest. This is usually caused by the influence of a companion galaxy, but none could be found until now – the team thinks VIRGOHI 21 is the culprit.
"The Dark Galaxy theory explains both the observations of VIRGOHI 21 and the mystery of NGC 4254," says Dr. Robert Minchin of the Arecibo Observatory.
Gas from NGC 4254 is being torn away by the dark galaxy, forming a temporary link between the two and stretching the arm of the spiral galaxy. As the VIRGOH1 21 moves on, the two will separate and NGC 4254's unusual arm will relax back to match its partner.
The team have looked at many other possible explanations, but have found that only the Dark Galaxy theory can explain all of the observations. As Professor Mike Disney of Cardiff University puts it, "The new observations make it even harder to escape the conclusion that VIRGOHI 21 is a Dark Galaxy."
"We're going to be searching for more Dark Galaxies with the new ALFA instrument at Arecibo Observatory," explains Dr. Jon Davies of Cardiff University. "We hope to find many more over the next few years – this is a very exciting time!"
Casey Kazan
Image: The dark galaxy VIRGOHI 21 has no starlight, but radio waves from neutral hydrogen gas betray its existence. The contours superimposed on this colour optical image from the Isaac Newton Telescope in the Canary Islands indicate how much gas was detected with the Westerbork Synthesis Radio Telescope. Credit: R. Minchin / Arecibo Observatory / Cardiff University / Isaac Newton Telescope / Westerbork Synthesis Radio Telescope.
New evidence has been discovered by an international team led by astronomers from the National Science Foundation's Arecibo Observatory and from Cardiff University in the United Kingdom that VIRGOHI 21, a mysterious cloud of hydrogen in the Virgo Cluster 50 million light-years from the Earth, is a Dark Galaxy, emitting no starlight. Their results not only indicate the presence of a dark galaxy but also explain the long-standing mystery of its strangely stretched neighbour. Skeptics of the dark-matter interpretation argue that VIRGOHI21 is simply a tidal tail of the nearby galaxy NGC 4254.
The observations, made with the Westerbork Synthesis Radio Telescope in the Netherlands, show that the hydrogen gas in VIRGOHI 21 appears to be rotating, suggesting a dark galaxy with over ten billion times the mass of the Sun. Only one percent of this mass has been detected as neutral hydrogen – the rest appears to be dark matter.
The results may also solve a long-standing puzzle about nearby galaxy NGC 4254 -a lopsided object, with one spiral arm much larger than the rest. This is usually caused by the influence of a companion galaxy, but none could be found until now – the team thinks VIRGOHI 21 is the culprit.
"The Dark Galaxy theory explains both the observations of VIRGOHI 21 and the mystery of NGC 4254," says Dr. Robert Minchin of the Arecibo Observatory.
Gas from NGC 4254 is being torn away by the dark galaxy, forming a temporary link between the two and stretching the arm of the spiral galaxy. As the VIRGOH1 21 moves on, the two will separate and NGC 4254's unusual arm will relax back to match its partner.
The team have looked at many other possible explanations, but have found that only the Dark Galaxy theory can explain all of the observations. As Professor Mike Disney of Cardiff University puts it, "The new observations make it even harder to escape the conclusion that VIRGOHI 21 is a Dark Galaxy."
"We're going to be searching for more Dark Galaxies with the new ALFA instrument at Arecibo Observatory," explains Dr. Jon Davies of Cardiff University. "We hope to find many more over the next few years – this is a very exciting time!"
Casey Kazan
Image: The dark galaxy VIRGOHI 21 has no starlight, but radio waves from neutral hydrogen gas betray its existence. The contours superimposed on this colour optical image from the Isaac Newton Telescope in the Canary Islands indicate how much gas was detected with the Westerbork Synthesis Radio Telescope. Credit: R. Minchin / Arecibo Observatory / Cardiff University / Isaac Newton Telescope / Westerbork Synthesis Radio Telescope.
The last unmapped white space of the map of the planet is Antarctica's Gamburtsev mountains, a subglacial mountain range discovered by the 3rd Soviet Antarctic Expedition in 1958 and is named for Soviet geophysicist Grigoriy A. Gamburtsev.
“These are mountain ranges that formed by the collision of tectonic plates,” said Dr Michael Studinger from the Lamont-Doherty Earth Observatory (LDEO) of Columbia University, New York.
and one of the leading scientists on the Antarctica’s Gamburtsev Province project,
The mountains were discovered by the Soviet team during the International Geophysical Year in 1957-8. Their detection was a complete surprise because the rock bed in the middle of the Antarctic continent was assumed to be relatively flat. It led some scientists to speculate that the Gamburtsevs might be old “hot spot” volcanoes that had punched their way through the Earth’s crust, much like the Hawaiian islands have done in the middle of the Pacific.
The international team spent two months in 2008/9 surveying the Gamburtsevs in Antarctica - a series of peaks totally buried under the ice cap. The shrounded Alp-like range is some 750 miles long, with jagged peaks the mountains are believed to be 8,900 ft high, completely covered by over 600 2,000 feet of ice and snow. The Gamburtsev Mountain Range is currently believed to be about the same size as the European Alps, and it is still unknown how the mountains were formed, though the current speculated age of the range is over 34 million years and possibly 500 million years.[
The range is being mapped by the Antarctica's Gamburtsev Province project,which has produced some awesome science often at brutal –80C conditions. AGAP aircraft flew a total of 120,000 miles in 2007-8 to map the area, gathering gravity, radar, magnetic and ice layer information.
The survey data revealed a very rugged landscape with high peaks and deeply incised valleys which have been worked in the past by both river and ice processes. "Before we had this data we couldn't see the valleys and therefore we had no way of being able to quantify the role of glacial and fluvial processes which is key to understanding cryosphere and climate evolution," said Dr Fausto Ferraccioli from the British Antarctic Survey.Studying what happened in these valleys could give clues as to how fast the Gamburtsevs became encased in ice.
"We're really excited about being able to use this dataset to see how valleys that were carved by rivers and then overprinted by glaciers are now driving waters underneath the ice sheet."
In addition, Dr Ferraccioli said it was possible a location could be found where ices might be drilled to retrieve information on the ancient climate of Antarctica. "There could be ice that is older than 1.2 million years - somewhere between 1.2 and 1.5 million years," he told BBC News. "We will have to do an analysis of the ice layers. But I think it's going to be quite a challenge because the topography is very rough and the layers are quite buckled."
Two instrumented Twin-Otter aircraft were flown out of remote field camps and collected a range of data. They crisscrossed the hidden peaks, flying a total of 120,000km. They gathered gravity, magnetic and ice thickness information, took radar images of the rock bed and the layers within the ice; and made a map of the ice-sheet's surface with a laser.
"We have now reached a point in the data processing that allows us to start scientific work with the data," Dr Studinger told BBC News. The science and mapping team has discovered ice that reaches down 4800 metres compared to Mount Everest's 6193.6 metres.
The mountains appear to be are filling in some major gaps in the understanding of the history of the continent. Antarctica was a standard-model continent in the days of the dinosaurs. Before Australia broke off, it's believed that the Antarctic was like modern-day Scandinavia, with cold seasons and long days and nights. The mountains are thought to have acted as the areas of formation of the modern ice sheets, which are only 30 million years old.
One of the more interesting in a long list of interesting discoveries is the finding of some free water within the deep ice. The geophysical properties of these areas aren't clear, and there's likely to be some new science involved in explaining their structure and formation.
These discoveries are only the beginning. AGAP's scientists have a lot of work to do, just analyzing this data. The AGAP survey represents a new benchmark in earth sciences, a truly tough piece of work which has redefined both the capabilities and the importance of geological survey and science.
Casey Kazan
http://www.digitaljournal.com/article/284141
Stunning images of an unstable fusion reactor so vast it can only be kept in space. It’s not the next disaster movie (though they’re bound to run out of Earth landmarks son enough) but a glimpse of the far future: a sun-like star going through its death throes under observation by astronomers. Let’s hope they’ve got popcorn.
Chi Cygni is a wildly variable star: hundreds of light years away, it can range from visible with the naked eye to undetectable without a large telescopes, and it’s got a very good excuse for such unstable behaviour. It’s dying. Having expended its hydrogen core the star is now being crushed by the force of gravity. But stars don’t go quietly into the night, with the increased pressure and temperature triggering intense fusion reactions of other materials in areas around the core - blasting pieces of the star into space and creating an an extremely asymmetrical pulsating surface.
Chi Cygni is only five billion (plus a few hundred) years ahead of our own Sun - it’s at the point where it would have eaten Mars, had we been careless enough to live in a Chi Cygni-lar system instead of a solar one. Scientists of the Observatoire de Paris are studying the breakdown using the infra-red interferometric IOTA telescope in Arizona. The star will eventually explode, blasting off most of its outer mass into a nebula when the core collapses into a white dwarf.
It’s the ultimate in mortality; never mind men dying left and right, this is a spectacular study in how even the very symbol of life will violently expire. Though if man last long enough to deal with Sol’s slow death, we’ll be doing far better than we expect - in fact, if we even make it long enough to see Chi’s final death we’ll beat of the odds.
Luke McKinney
Imagine being roused by an attendant floating in zero gravity from a years-long sleep just before landing on a distant inhabited moon, Pandora. What you would soon discover is an exotic DNA carbon-based alien world.
In the new blockbuster Avatar, director James Cameron places his bet squarely on the “life as carbon-based DNA” camp. With NASA’s Kepler mission showing the potential to detect Earth-sized objects, habitable moons may soon become science fact. If we find them nearby, a new paper by Smithsonian astronomer Lisa Kaltenegger shows that the James Webb Space Telescope (JWST) will be able to study their atmospheres and detect key gases like carbon dioxide, oxygen, and water vapor.
“If Pandora existed, we potentially could detect it and study its atmosphere in the next decade,” said Lisa Kaltenegger of the Harvard-Smithsonian Center for Astrophysics (CfA).
So far, planet searches have spotted hundreds of Jupiter-sized objects in a range of orbits. Gas giants, while easier to detect, could not serve as homes for life as we know it. However, scientists have speculated whether a rocky moon orbiting a gas giant could be life-friendly, if that planet
orbited within the star’s habitable zone (the region warm enough for liquid
water to exist).
“All of the gas giant planets in our solar system have rocky and icy moons,” said Kaltenegger. “That raises the possibility that alien Jupiters will also have moons. Some of those may be Earth-sized and able to hold onto an atmosphere.”
Kepler looks for planets that cross in front of their host stars, which creates a mini-eclipse and dims the star by a small but detectable amount. Such a transit lasts only hours and requires exact alignment of star and planet along our line of sight. Kepler will examine thousands of stars to
find a few with transiting worlds.
Once they have found an alien Jupiter, astronomers can look for orbiting moons, or exomoons. A moon’s gravity would tug on the planet and either speed or slow its transit, depending on whether the moon leads or trails the planet. The resulting transit duration variations would indicate the moon’s existence.
Once a moon is found, the next obvious question would be: Does it have an atmosphere? If it does, those gases will absorb a fraction of the star’s light during the transit, leaving a tiny, telltale fingerprint to the atmosphere’s composition.
The signal is strongest for large worlds with hot, puffy atmospheres, but an Earth-sized moon could be studied if conditions are just right. For example, the separation of moon and planet needs to be large enough that we could catch just the moon in transit, while its planet is off to one side of the star.
Kaltenegger calculated what conditions are best for examining the atmospheres of alien moons. She found that alpha Centauri A, the system featured in Avatar, would be an excellent target.
“Alpha Centauri A is a bright, nearby star very similar to our Sun, so it gives us a strong signal” Kaltenegger explained. “You would only need a handful of transits to find water, oxygen, carbon dioxide, and methane on an Earth-like moon such as Pandora.”
“If the Avatar movie is right in its vision, we could characterize that moon with the James Webb Space Telescope in the near future,” she added.
While Alpha Centauri A offers tantalizing possibilities, small, dim, red dwarf stars are better targets in the hunt for habitable planets or moons. The habitable zone for a red dwarf is closer to the star, which increases the probability of a transit.
Astronomers have debated whether tidal locking could be a problem for red dwarfs. A planet close enough to be in the habitable zone would also be close enough for the star’s gravity to slow it until one side always faces the star. (The same process keeps one side of the Moon always facing Earth.) One side of the planet then would be baked in constant sunlight, while the
other side would freeze in constant darkness.
An exomoon in the habitable zone wouldn’t face this dilemma. The moon would be tidally locked to its planet, not to the star, and therefore would have regular day-night cycles just like Earth. Its atmosphere would moderate temperatures, and plant life would have a source of energy moon-wide.
“Alien moons orbiting gas giant planets may be more likely to be habitable than tidally locked Earth-sized planets or super-Earths,” said Kaltenegger. “We should certainly keep them in mind as we work toward the ultimate goal of finding alien life.”
So what about Cameron’s Na’vi? Will our first discovery of life beyond Earth be DNA and carbon-based? At once humanoid and tantalizingly exotic, the 10-foot, blue-skinned Na'vi come with supermodel dimensions; long articulated digits, the better to grip with; and the slanted eyes and ears of a cat.
In his famous lecture, “Life in the Universe,” Stephen Hawking observed that what we normally think of as ‘life’ is based on chains of carbon atoms, with a few other atoms, such as nitrogen or phosphorous. We can imagine that one might have life with some other chemical basis, such as silicon, “but carbon seems the most favorable case, because it has the richest chemistry.”
Several eminent scientists think otherwise, that life in the universe could have a myriad of possible biochemical foundations ranging from life in ammonia to life in hydrocarbons and silicon. Silicates have a rich chemistry with a propensity for forming chains, rings, and sheets. One of the founders on modern genetics, Cairn-Smith, argued that layers of crystalline silicates functioned as a primitive form of life on early Earth, before they evolved into carbon-based life forms.
The Earth (and we’re assuming, Pandora) was formed largely out of the heavier elements, including carbon and oxygen. Somehow, Hawking observes, “some of these atoms came to be arranged in the form of molecules of DNA. One possibility is that the formation of something like DNA, which could reproduce itself, is extremely unlikely. However, in a universe with a very large, or infinite, number of stars, one would expect it to occur in a few stellar systems, but they would be very widely separated.”
Other prominent scientists have warned that we humans may be blinded by our familiarity with carbon and Earth-like conditions. In other words, what we're looking for may not even lie in our version of a "sweet spot" in the Galactic Habitable Zone. After all, even here on Earth, one species "sweet spot" is another species worst nightmare. In any case, it is not beyond the realm of feasibility that our first encounter with extraterrestrial life will not be a solely carbon-based fete.
Alternative biochemists speculate that there are several atoms and solvents that could potentially spawn life. Because carbon has worked for the conditions on Earth, we speculate that the same must be true throughout the universe. In reality, there are many elements that could potentially do the trick. Even counter-intuitive elements such as arsenic may be capable of supporting life under the right conditions. Even on Earth some marine algae incorporate arsenic into complex organic molecules such as arsenosugars and arsenobetaines.
Several other small life forms use arsenic to generate energy and facilitate growth. Chlorine and sulfur are also possible elemental replacements for carbon. Sulfur is capably of forming long-chain molecules like carbon. Some terrestrial bacteria have already been discovered to survive on sulfur rather than oxygen, by reducing sulfur to hydrogen sulfide.
Nitrogen and phosphorus could also potentially form biochemical molecules. Phosphorus is similar to carbon in that it can form long chain molecules on its own, which would conceivably allow for formation of complex macromolecules. When combined with nitrogen, it can create quite a wide range of molecules, including rings.
So what about water? Isn't at least water essential to life?
Not necessarily. Ammonia, for example, as we mentioned above has many of the same properties as water. An ammonia or ammonia-water mixture stays liquid at much colder temperatures than plain water. Such biochemistries may exist outside the conventional water-based “habitability zone”. One example of such a location would be right here in our own solar system on Saturn’s largest moon Titan.
Hydrogen fluoride methanol, hydrogen sulfide, hydrogen chloride, and formamide have all been suggested as suitable solvents that could theoretically support alternative biochemistry. All of these "water replacements" have pros and cons when considered in our terrestrial environment. What needs to be considered is that with a radically different environment, comes radically different reactions. Water and carbon might be the very last things capable of supporting life in some extreme planetary conditions.
While some of these scenarios may seem the stuff of science finction, it’s important to keep in mind that the foundations of life on Earth, the association of a protein with a nucleic acid when view abstractly, does little to convey the endgame wonders such as blue whales and Mozart’s operas.
A billion years from now our descendants may have discovered other systems of physical life such as plasma within stars which would be based on the reciprocal influence of patterns of magnetic force and the ordered motion of charged particles. In fact, such life may well exists within our Sun.
Another form would be based on radiation emitted by isolated atoms and molecules in a dense interstellar cloud similar to the one physicist Fred Hoyle described in his scifi thriller, The Black Cloud. Such clouds can have a long lifetime lasting millions of years before they collapse.
Our personal favorite at The Daily Galaxy is the possibility of life in Neutron stars which would be based on the properties of polymeric atoms which which could form chains that could store and transmit information in a way that bears an uncanny similarity to the functions of nucleic acids -the molecules that carry genetic information or form structures within cells.
In the meantime, you can be sure I’ll be dreaming of the exotic and very sexy carbon-based Neytiri, the slinky Na’vi heroine -tail and all.
Casey Kazan - sourced from materials provided by the Harvard-Smithsonian Center for
Astrophysics (CfA) and New York Times article by Manhola Dargis
Imagine being roused by an attendant floating in zero gravity from a years-long sleep just before landing on a distant inhabited moon, Pandora. What you would soon discover is an exotic DNA carbon-based world on a twin Earth.
In the new blockbuster Avatar, director James Cameron places his be squarely in the “life as carbon-based DNA” camp. With NASA’s Kepler mission showing the potential to detect Earth-sized objects, habitable moons may soon become science fact. If we find them nearby, a new paper by Smithsonian astronomer Lisa Kaltenegger shows that the James Webb Space Telescope (JWST) will be able to study their atmospheres and detect key gases like carbon dioxide, oxygen, and water vapor.
“If Pandora existed, we potentially could detect it and study its atmosphere in the next decade,” said Lisa Kaltenegger of the Harvard-Smithsonian Center for Astrophysics (CfA).
So far, planet searches have spotted hundreds of Jupiter-sized objects in a range of orbits. Gas giants, while easier to detect, could not serve as homes for life as we know it. However, scientists have speculated whether a rocky moon orbiting a gas giant could be life-friendly, if that planet
orbited within the star’s habitable zone (the region warm enough for liquid
water to exist).
“All of the gas giant planets in our solar system have rocky and icy moons,” said Kaltenegger. “That raises the possibility that alien Jupiters will also have moons. Some of those may be Earth-sized and able to hold onto an atmosphere.”
Kepler looks for planets that cross in front of their host stars, which creates a mini-eclipse and dims the star by a small but detectable amount. Such a transit lasts only hours and requires exact alignment of star and planet along our line of sight. Kepler will examine thousands of stars to
find a few with transiting worlds.
Once they have found an alien Jupiter, astronomers can look for orbiting moons, or exomoons. A moon’s gravity would tug on the planet and either speed or slow its transit, depending on whether the moon leads or trails the planet. The resulting transit duration variations would indicate the moon’s existence.
Once a moon is found, the next obvious question would be: Does it have an atmosphere? If it does, those gases will absorb a fraction of the star’s light during the transit, leaving a tiny, telltale fingerprint to the atmosphere’s composition.
The signal is strongest for large worlds with hot, puffy atmospheres, but an Earth-sized moon could be studied if conditions are just right. For example, the separation of moon and planet needs to be large enough that we could catch just the moon in transit, while its planet is off to one side of the star.
Kaltenegger calculated what conditions are best for examining the atmospheres of alien moons. She found that alpha Centauri A, the system featured in Avatar, would be an excellent target.
“Alpha Centauri A is a bright, nearby star very similar to our Sun, so it gives us a strong signal” Kaltenegger explained. “You would only need a handful of transits to find water, oxygen, carbon dioxide, and methane on an Earth-like moon such as Pandora.”
“If the Avatar movie is right in its vision, we could characterize that moon with the James Webb Space Telescope in the near future,” she added.
While Alpha Centauri A offers tantalizing possibilities, small, dim, red dwarf stars are better targets in the hunt for habitable planets or moons. The habitable zone for a red dwarf is closer to the star, which increases the probability of a transit.
Astronomers have debated whether tidal locking could be a problem for red dwarfs. A planet close enough to be in the habitable zone would also be close enough for the star’s gravity to slow it until one side always faces the star. (The same process keeps one side of the Moon always facing Earth.) One side of the planet then would be baked in constant sunlight, while the
other side would freeze in constant darkness.
An exomoon in the habitable zone wouldn’t face this dilemma. The moon would be tidally locked to its planet, not to the star, and therefore would have regular day-night cycles just like Earth. Its atmosphere would moderate temperatures, and plant life would have a source of energy moon-wide.
“Alien moons orbiting gas giant planets may be more likely to be habitable than tidally locked Earth-sized planets or super-Earths,” said Kaltenegger. “We should certainly keep them in mind as we work toward the ultimate goal of finding alien life.”
So what about Cameron’s Na’vi? Will our first discovery of life beyond Earth be DNA and carbon-based? At once humanoid and tantalizingly exotic, the 10-foot, blue-skinned Na'vi come with supermodel dimensions; long articulated digits, the better to grip with; and the slanted eyes and ears of a cat.
In his famous lecture, “Life in the Universe,” Stephen Hawking observed that what we normally think of as ‘life’ is based on chains of carbon atoms, with a few other atoms, such as nitrogen or phosphorous. We can imagine that one might have life with some other chemical basis, such as silicon, “but carbon seems the most favorable case, because it has the richest chemistry.”
Several eminent scientists think otherwise, that life in the universe could have a myriad of possible biochemical foundations ranging from life in ammonia to life in hydrocarbons and silicon. Silicates have a rich chemistry with a propensity for forming chains, rings, and sheets. One of the founders on modern genetics, Cairn-Smith, argued that layers of crystalline silicates functioned as a primitive form of life on early Earth, before they evolved into carbon-based life forms.
The Earth (and we’re assuming, Pandora) was formed largely out of the heavier elements, including carbon and oxygen. Somehow, Hawking observes, “some of these atoms came to be arranged in the form of molecules of DNA. One possibility is that the formation of something like DNA, which could reproduce itself, is extremely unlikely. However, in a universe with a very large, or infinite, number of stars, one would expect it to occur in a few stellar systems, but they would be very widely separated.”
Other prominent scientists have warned that we humans may be blinded by our familiarity with carbon and Earth-like conditions. In other words, what we're looking for may not even lie in our version of a "sweet spot" in the Galactic Habitable Zone. After all, even here on Earth, one species "sweet spot" is another species worst nightmare. In any case, it is not beyond the realm of feasibility that our first encounter with extraterrestrial life will not be a solely carbon-based fete.
Alternative biochemists speculate that there are several atoms and solvents that could potentially spawn life. Because carbon has worked for the conditions on Earth, we speculate that the same must be true throughout the universe. In reality, there are many elements that could potentially do the trick. Even counter-intuitive elements such as arsenic may be capable of supporting life under the right conditions. Even on Earth some marine algae incorporate arsenic into complex organic molecules such as arsenosugars and arsenobetaines.
Several other small life forms use arsenic to generate energy and facilitate growth. Chlorine and sulfur are also possible elemental replacements for carbon. Sulfur is capably of forming long-chain molecules like carbon. Some terrestrial bacteria have already been discovered to survive on sulfur rather than oxygen, by reducing sulfur to hydrogen sulfide.
Nitrogen and phosphorus could also potentially form biochemical molecules. Phosphorus is similar to carbon in that it can form long chain molecules on its own, which would conceivably allow for formation of complex macromolecules. When combined with nitrogen, it can create quite a wide range of molecules, including rings.
So what about water? Isn't at least water essential to life?
Not necessarily. Ammonia, for example, as we mentioned above has many of the same properties as water. An ammonia or ammonia-water mixture stays liquid at much colder temperatures than plain water. Such biochemistries may exist outside the conventional water-based “habitability zone”. One example of such a location would be right here in our own solar system on Saturn’s largest moon Titan.
Hydrogen fluoride methanol, hydrogen sulfide, hydrogen chloride, and formamide have all been suggested as suitable solvents that could theoretically support alternative biochemistry. All of these "water replacements" have pros and cons when considered in our terrestrial environment. What needs to be considered is that with a radically different environment, comes radically different reactions. Water and carbon might be the very last things capable of supporting life in some extreme planetary conditions.
While some of these scenarios may seem the stuff of science finction, it’s important to keep in mind that the foundations of life on Earth, the association of a protein with a nucleic acid when view abstractly, does little to convey the endgame wonders such as blue whales and Mozart’s operas.
A billion years from now our descendants may have discovered other systems of physical life such as plasma within stars which would be based on the reciprocal influence of patterns of magnetic force and the ordered motion of charged particles. In fact, such life may well exists within our Sun.
Another form would be based on radiation emitted by isolated atoms and molecules in a dense interstellar cloud similar to the one physicist Fred Hoyle described in his scifi thriller, The Black Cloud. Such clouds can have a long lifetime lasting millions of years before they collapse.
Our personal favorite at The Daily Galaxy is the possibility of life in Neutron stars which would be based on the properties of polymeric atoms which which could form chains that could store and transmit information in a way that bears an uncanny similarity to the functions of nucleic acids -the molecules that carry genetic information or form structures within cells.
In the meantime, you can be sure I’ll be dreaming of the exotic and very sexy carbon-based Neytiri, the slinky Na’vi heroine -tail and all.
Casey Kazan - sourced from materials provided by the Harvard-Smithsonian Center for
Astrophysics (CfA).
Study of the stars has always driven mankind forward. From the earliest urge to look above ourselves, when Orion’s Belt truly belonged to an immense being above us, through navigation of the seas in exploration of our own planet, to untangling spacetime itself, the sky has always showered us with information. Now some say space could show us the legendary Higgs boson -for free.
The thing about the universe is that it’s indescribably big, and any astrophysical event we can conceive of has probably already happened. This is part of why the anti-LHC crowd are so retro: claiming that a few monkeys bashing rocks together on Earth could tear a hole in a universe which has been blowing things up on unimaginable scales since day one. They defend their mistake by explaining “but we’re slamming energetic particles into each other, and in space that doesn’t happen,” which shows such staggering lack of understanding you’re allowed to pretend you can’t hear them. But don’t do that (it’s their tactic), so simply explain that yes, energetic particles do occasionally encounter each other - even in space! (You may work your way up to explaining especially in space if you make progress.)
One cosmic collision experiment which may already be happening is the production of Higgs bosons. Professor Tim Tait of the University of California and colleagues suggest that this could occur when dark matter particles, which act as their own anti-matter, hit each other and annihilate. According to the model they use most such reactions would generate a pair of equal energy gamma rays, but some would shunt most of the mass energy into the Higgs Boson - leaving a weak gamma ray signal we could see.
The best thing about this experiment is that we can already observe it. The HESS (High Energy Stereoscopic System) telescope, VERITAS (Very Energetic Radiation Imaging Telescope Array System) telescope and FERMI (Not Actually An Acronym) satellite systems would all observe the resulting gamma ray spectra. And since observing the universe is what they do already, it isn’t even any extra work.
It’s such a good sign of mankind’s progress - there is just so much stunning stuff to be found, it’s only a matter of what we know how to look for. When you get to the point of dark-matter annihilation-created standard model particles, we’ve come a long way from thinking giant all-powerful voyeurs were watching us at every moment.
Luke McKinney
Higgs in Space? http://www.newscientist.com/article/mg20427384.100-higgs-in-space-orbiting-telescope-could-beat-the-lhc.html?DCMP=OTC-rss&nsref=cosmology
Saturn’s Titan has been
considered a "unique world in the solar system" since 1908 when, the
Spanish astronomer, José Comas y Solá, discovered that it had an
atmosphere, something non-existent on other moons.
It seems perfectly appropriate that one of the prime candidates for
life in our solar system, Saturn’s largest moon, Titan, should have
surface lakes, lightning, shorelines, relatively thick nitrogen
atmosphere -and seasons. Titan can be viewed as an early-model Earth.
And 100% of all known Earths have awesome life on them. The
significantly lower temperature is a bit of a stumbling block (it’s ten
times as far from the sun as us), but there’s a strong possibility of
subterranean microbial life - or even a prebiotic “Life could happen!”
environment.
If a space traveler ever visits Titan, they will find a world where
temperatures plunge to minus 274 degrees Fahrenheit, methane rains from
the sky and dunes of ice or tar cover the planet’s most arid regions -a
cold mirror image of Earth’s tropical climate, according to scientists
at the University of Chicago.
Titan’s ice is stronger than most bedrock found on earth, yet it is more brittle, causing it to erode more easily, according to new research by San Francisco State University Assistant Professor Leonard Sklar. Sklar and his team developed new measurements from tests on ice as cold as minus 170 degrees Celcius which demonstrate that ice gets stronger as temperature decreases. Understanding ice and its resistance to erosion is critical to answering how Titan’s earth-like landscape formed. Titan has lakes, rivers and dunes, but its bedrock is made of ice as cold as minus 180 degrees Celcius, eroded by rivers of liquid methane.
“You have all these things that
are analogous to Earth. At the same time, it’s foreign and unfamiliar,”
said Ray Pierrehumbert, the Louis Block Professor in Geophysical
Sciences at Chicago.
Titan, one of Saturn’s 60 moons, is the
only moon in the solar system large enough to support an atmosphere.
Pierrehumbert and colleague Jonathan Mitchell, have been comparing
observations of Titan collected by the Cassini space probe and the
Hubble Space Telescope with their own computer simulations of the
moon’s atmosphere.
“One of the things that attracts me about
Titan is that it has a lot of the same circulation features as Earth,
but done with completely different substances that work at different
temperatures,” Pierrehumbert said. On Earth, for example, water forms
liquid and is relatively active as a vapor in the atmosphere. But on
Titan, water is a rock. “It’s not more volatile on Titan than sand is
on Earth.”
Methane-natural gas-assumes an Earth-like role of
water on Titan. It exists in enough abundance to condense into rain and
form puddles on the surface within the range of temperatures that occur
on Titan.
“The ironic thing on Titan is that although it’s much
colder than Earth, it actually acts like a super-hot Earth rather than
a snowball Earth, because at Titan temperatures, methane is more
volatile than water vapor is at Earth temperatures,” Pierrehumbert said.
Pierrehumbert
and Mitchell even go so far as to call Titan’s climate tropical, even
though it sounds odd for a moon that orbits Saturn more than nine times
farther from the sun than Earth. Along with the behavior of methane,
Titan’s slow rotation rate also contributes to its tropical nature.
Earth’s tropical weather systems extend only to plus or minus 30
degrees of latitude from the equator. But on Titan, which rotates only
once every 16 days, “the tropical weather system extends to the entire
planet,” Pierrehumbert said.
Titan’s dense, nitrogen-methane atmosphere responds much more slowly
than Earth’s atmosphere, as it receives about 100 times less sunlight than Earth. Seasons on Titan last more
than seven Earth years. Its clouds form and move much like those on Earth, but in a much slower, more lingering fashion.
Physicists
from the University of Granada and University of Valencia, analyzing
data sent by the Cassini-Huygens probe from Titan, have "unequivocally"
proved that there is natural electrical activity on Titan. The world
scientist community believes that the probability of organic molecules,
precursors of life, being formed is higher on planets or moons which
have an atmosphere with electrical storms.
Scientists
with NASA’s Cassini mission have monitored Titan’s atmosphere for
three-and-a-half years, between July 2004 and December 2007, and
observed more than 200 clouds. They found that the way these clouds are
distributed around Titan matches scientists’ global circulation models.
The only exception is timing — clouds are still noticeable in the
southern hemisphere while fall is approaching.
“Titan’s clouds
don’t move with the seasons exactly as we expected,” said Sebastien
Rodriguez of the University of Paris Diderot, in collaboration with
Cassini visual and infrared mapping spectrometer team members at the
University of Nantes, France. “We see lots of clouds during the summer
in the southern hemisphere, and this summer weather seems to last into
the early fall. It looks like Indian summer on Earth, even if the
mechanisms are radically different on Titan from those on Earth. Titan
may then experience a warmer and wetter early autumn than forecasted by
the models.”
On Earth, abnormally warm, dry weather periods in
late autumn occur when low-pressure systems are blocked in the winter
hemisphere. By contrast, scientists think the sluggishness of
temperature changes at the surface and low atmosphere on Titan may be
responsible for its unexpected warm and wet, hence cloudy, late summer.
Scientists will continue to observe the long-term changes during Cassini’s extended mission, which runs until the fall of 2010,
which will offer plenty of opportunities to monitor climate change on
Titan — the spacecraft makes its next flyby of the moon on June 6.
We’ll learn if the sluggish weather is the result of a slow rate of
temperature change at the surface.
The Cassini-Huygens mission is a cooperative project of NASA, the European Space Agency and the Italian Space Agency.
Titan’s South Polar Cloud Burst The infrared image of Saturn’s moon
Titan shows a large burst of clouds in the moon’s south polar region.
Image credit: NASA/JPL/University of Arizona/University of Nantes
Posted by Casey Kazan.
Image Top: Titan’s vast dune fields may act like weather vanes to determine general wind direction, have been mapped by scientists who compiled four years of radar data collected by the Cassini spacecraft.
Adapted from materials provided by the University of Chicago and the following sources:
http://www1.nasa.gov/mission_pages/cassini/media/cassini-20090603.html
Adapted from materials provided by Plataforma SINC, via AlphaGalileo.
http://www.sciencedaily.com/releases/2008/07/080729075117.htm
http://www.scientificblogging.com/news_releases/confirmed_electrical_activity_on_titan
http://www.centauri-dreams.org/?p=8105
New infrared images showing the global cloud pattern are available at: http://saturn.jpl.nasa.gov and
http://www.nasa.gov/cassini .
Image: Planet GJ 1214b orbiting its red dwarf star. The Hubble telescope will reveal whether it is suitable for life. Artist’s impression: David A. Aguilar/CfA
