News From Space: Kepler Finds Many New Worlds!

exoplanets2Late last month, NASA announced the discovery of 715 more exoplanets, nearly doubling the number of planets beyond our Solar System. These newly-verified worlds orbit 305 stars, revealing multiple-planet systems outside of our own, with four of them within their stars habitable zones. It’s the single largest windfall of new confirmations at any one time, and its all thanks to a new verification technique employed by the Kepler space probe’s scientists.

Nearly 95 percent of these planets are smaller than Neptune, which is almost four times the size of Earth. What’s more, this latest batch of exoplanets puts the total number of those confirmed from about 1000 to just over 1700 – and increase of 70% that occurred overnight! This discovery marks a significant increase in the number of known small-sized planets more akin to Earth than previously identified exoplanets.

alien-worldJohn Grunsfeld, associate administrator for NASA’s Science Mission Directorate in Washington, had this to say in a press release:

The Kepler team continues to amaze and excite us with their planet hunting results. That these new planets and solar systems look somewhat like our own, portends a great future when we have the James Webb Space Telescope in space to characterize the new worlds.

Since the discovery of the first planets outside our solar system roughly two decades ago, verification has been a laborious planet-by-planet process. Now, scientists have a statistical technique that can be applied to many planets at once when they are found in the same planetary systems. From NASA’s Ames Research Center in Moffett Field, Calif, the Kepler research team used a technique called verification by multiplicity, which relies in part on the logic of probability.

Kepler78b1The Kepler space probe observes some 150,000 stars and has found a few thousand of those to have planet candidates. If the candidates were randomly distributed among Kepler’s stars, only a handful would have more than one planet candidate. However, Kepler observed hundreds of stars that have multiple planet candidates. Through a careful study of this sample, these 715 new planets were verified.

This method can be likened to the behavior we know of lions and lionesses – where the lions are the Kepler stars and the lionesses are the planet candidates. The lionesses would sometimes be observed grouped together whereas lions tend to roam on their own. If more than two large felines are gathered, then it is very likely to be a lion and his pride. Thus, through multiplicity the lioness can be reliably identified in much the same way multiple planet candidates can be found around the same star.

Kepler-telescope-580x448Jack Lissauer, c0-leader of the Kepler science team at NASA’s Ames Research Center, explains the difference this process ushers in:

Four years ago, Kepler began a string of announcements of first hundreds, then thousands, of planet candidates –but they were only candidate worlds. We’ve now developed a process to verify multiple planet candidates in bulk to deliver planets wholesale, and have used it to unveil a veritable bonanza of new worlds.

Of these planets, the vast majority are small, boosting the number of known small Earth-sized planets by a factor of 400%. Other jumps include a 600% increase is known Super-Earths (or Mini-Neptunes), a 200% boost for Neptune-sized planets, and just 2% for Jupiter-sized planets. The 305 solar systems are also quite similar to our own, with the planets orbiting along a flat plane in tightly-packed, nearly circular orbits.

kepler_graphAs noted, the Kepler scientists confirmed the existence of four planets situated within their solar system’s habitable zone. They are Kepler-174d, Kepler-296f, Kepler-298d and Kepler-309c, are less than 2.5 times the size of Earth, and all orbit around M and K stars. Kepler-296f is especially interesting, in that it orbits a star half the size and 5 percent as bright as our sun, and is either a gaseous planet composed of hydrogen-helium, or a water world surrounded by a deep ocean.

In the meantime, NASA has released this animated graph (shown above) to put all the discoveries into context. And while the discovery of only four potentially habitable planets amongst 715 (a mere 0.0056% of the total) may seem discouraging, each discovery brings us one step closer to a more accurate understanding of our place in the galaxy. The findings papers will be published March 10 in The Astrophysical Journal.

Sources: IO9, (2), nasa.gov

News From Space: Alpha Centauri’s “Superhabitable” World

alpha_centauri_newsScientists and astronomers have learned a great deal about the universe in recent years, thanks to craft like the Kepler space probe and the recently launched Gaian space observatory. As these and other instruments look out into the universe and uncover stars and exoplanets, it not only lets us expand our knowledge of the universe, but gives us a chance to reflect upon the meaning of this thing we call “habitability”.

Basically, our notions of what constitutes a habitable environment are shaped by our own. Since Earth is a life-sustaining environment from which we originated, we tend to think that conditions on another life-giving planet would have to be similar. However, scientists René Heller and John Armstrong contend that there might be a planet even more suitable in this galaxy, and in the neighboring system of Alpha Centauri B.

alpha_centauriBb1For those unfamiliar, Alpha Centauri A/B is a triple star system some 4.3 light years away from Earth, making it the closest star system to Earth. The nice thing about having a hypothetical “superhabitable” planet in this system is that it makes it a lot easier to indulge in a bit of a thought experiment, and will make it that much more easy to observe and examine.

According to the arguments put forward by Heller, of the Department of Physics and Astronomy, McMaster University, Hamilton; and Armstrong, of the Department of Physics, Weber State University in Ogden, this planet may be even more suitable for supporting life than our own. It all comes down to meeting the particulars, and maybe even exceeding them.

habitable_sunsFor example, a habitable planet needs the right kind sun – one that has existed and remained stable for a long time. If the sun in question is too large, then it will have a very short life; and if it’s too small, it might last a long time. But the planet will have to be very close to stay warm and that can cause all sorts of problems, such as a tidally locked planet with one side constantly facing the sun.

Our own sun is a G2-type star, which means it has been alive and stable for roughly 4.6 billion years. However, K-type dwarfs, which are smaller than the Sun, have lives longer than the age of the universe. Alpha Centauri B is specifically a K1V-type star that fits the bill with an estimated age of between 4.85 and 8.9 billion years, and is already known to have an Earth-like planet called Alpha Centauri B b.

alpha_centauriBb2As to the superhabitable planet, assuming it exists, it will be located somewhere between 0.5 and 1.4 astronomical units (46 – 130 million mi, 75 – 209 million km) from Alpha Centauri B. All things being equal, it will have a circular orbit 1. 85 AU (276 million km / 172 million miles) away, which would place it in the middle of the star’s habitable zone.

Also, for a planet to sustain life it has to be geologically active, meaning it has to have a rotating molten core to generate a magnetic field to ward off cosmic radiation and protect the atmosphere from being stripped away by solar winds. A slightly more massive planet with more gravity means more tectonic activity, so a better magnetic field and a more stable climate.

 

PlutoHowever, the most striking difference between the superhabitable world and Earth would be that the former would lack our continents and deep oceans – both of which can be hostile to life. Instead, Heller and Armstrong see a world with less water than ours, which would help to avoid both a runaway greenhouse effect and a snowball planet that an overabundance of water can trigger.

Our superhabitable planet might not even be in the habitable zone. It could be a moon of some giant planet further away. Jupiter’s moon Io is a volcanic hellhole due to tidal heating, but a larger moon that Heller and Armstrong call a “Super Europa” in the right orbit around a gas giant could heat enough to support life even if it’s technically outside the star’s habitable zone.

 

alien-worldAccording to Heller and Armstrong, this world would look significantly different from our own. It would be an older world, larger and more rugged, and would provide more places for life to exist. What water there was would be evenly scattered across the surface in the form of lakes and small, shallow seas. And, it would also be slightly more massive, which would mean more gravity.

This way, the shallow waters would hold much larger populations of more diverse life than is found on Earth, while the temperatures would be more moderated. However, it would be a warmer world than Earth, which also makes for more diversity and potentially more oxygen, which the higher gravity would help with by allowing the planet to better retain its atmosphere.

panspermia1Another point made by Heller and Armstrong is that there may be more than one habitable planet in the Alpha Centauri B system. Cosmic bombardments early in the history of the Solar System is how the Earth got its water and minerals. If life had already emerged on one planet in the early history of the Alpha Centauri B system, then the bombardment might have spread it to other worlds.

But of course, this is all theoretical. Such a planet may or may not exist, and may or may not have triggered the emergence of life on other worlds within the system. But what is exciting about it is just how plausible its existence may prove to be, and how easy it will be to verify once we can get some space probes between here and there.

Just imagine the sheer awesomeness of being able to see it, the images of a super-sized Earth-moon beamed back across light years, letting us know that there is indeed life on worlds besides our own. Now imagine being able to study that life and learning that our conceptions of this too have been limited. What a time that will be! I hope we all live to see it…

 

 

Sources: gizmag.com, universetoday.com

News from Space: Full Model of Exoplanet Created

gliese_581gEver since the Kepler space probe began finding hard evidence of the existence of exoplanets – i.e. planets orbiting suns outside of our Solar System – scientists have been working hard to determine what conditions on these worlds must be like. For instance, it is known that planets that orbit closely to their red dwarf parent suns are tidally locked – meaning they do not rotate on their axis.

This, in turn, has led to the proposal that any watery worlds in the vicinity could form what’s called an “Eyeball Earth.” Being directly under the local star, with one side perpetually facing towards it, the light would be intense enough to melt a circular patch of water, while the rest of the planet would remain locked in a deep freeze. In short, not an ideal situation for supporting life.

eyeball_earthHowever, a new three-dimensional model has been created, thanks to the efforts of two researchers at Peking University. In their research paper, they suggest that ice and oceans on these planets would be dynamic, which is both good and bad. Basically, it means an Eyeball Earth has a narrower habitable zone, but that more of the surface has the potential to support life. It also means that the “eyeball” looks more like a lobster!

This paper represents the next step in scientific analysis of exoplanets. Initially, estimates of habitability – i.e. temperatures that could allow liquid water on the planet surface – were based on a single analysis of the planet’s atmosphere to see how much light reaches the surface. But, in the real world, atmospheres form clouds, distribute heat through winds and convection, and exhibit other sorts of complex behavior.

eyeball_earthThese are the sorts of things that are handled in the full, three-dimensional climate models built to study the Earth. Hence, the Peking research team adapted these same models to handle exoplanets that differed significantly from Earth. But these models didn’t capture a critical part of the distribution of heat on the Earth: the ocean circulation. Instead, it treated the entire ocean as a two-dimensional slab.

The new study corrects for that by using a coupled ocean-atmosphere climate model, the Community Climate System Model version 3. For their study, they used Gliese 581 g, a potentially Earth-like planet orbiting in the habitable zone of an red dwarf star 20 light years away. This planet, coincidentally, is ranked by NASA as being the most Earth-like exoplanet yet seen in the known universe.

Gliese_581_-_2010Critically for the model, it’s close enough to its host star to receive 866 Watts/square meter at the top of its atmosphere (whereas the Earth receives 1,366). Since it is not yet known what Gliese 581 g’s atmosphere looks like, the authors assumed an Earth-like composition, but varied the amount of CO2 to change the intensity of the greenhouse effect. From all this, the planet was assumed to be covered in a deep ocean.

After giving the model 1,100 years to come to equilibrium, the authors sampled a century of its climate. With carbon dioxide concentrations similar to the Earth’s (330 parts per million in the model), the “eyeball” vanished. That’s because ocean currents formed along the equator and brought in ice from the west that split the eyeball into two lobes that flanked the equator – which resemble the claws of the lobster.

eyeball_earth1The currents then transferred heat to the eastern portion of the planet, which melted the ice to form the lobster’s tail. In addition to the ocean current that altered ice distribution, an underwater circulation (similar to the one on Earth) formed, which sent warmer water toward the poles. In the atmosphere, a jet stream also formed over the equator, which also distributed some heat to the unlit side of the planet.

Ultimately, the new model suggests the habitable zone of watery planets near red dwarfs is a bit more narrow than previous studies had suggested. The good news is that, in this model, the ice never got more than 3m thick on the dayside of the planet. That’s thin enough to allow light to reach the water underneath, meaning photosynthesis is a possibility over the entire dayside of the planet.

OceanPlanetAlthough this model is a major improvement, it still lacks a key feature that’s likely to exist on planets – namely continents, or at least features on the seafloor that differ greatly in height. These will radically alter the currents on the planet, and thus radically alter the distribution of heat within the ocean. Unfortunately, this information is even harder to come by at present than atmospheric conditions.

So for the time being, all we really know about Gliese 581 g and other similar exoplanets is that their surfaces are icy, but habitable – not unlike the Jovian moon Europa. However, that is not to say that we won’t have more information in the near future. With Kepler still in operation and the Gaia space observatory now in space, we might be able to construct more detailed models of nearby exoplanets in the near future.

Also a coincidence, Gliese 581 g just happens to be the setting of my writers group’s upcoming anthology, known as Yuva. And with this latest bit of info under our belts (basically, that the entire planet is a big, watery ball), I imagine we’ll have to adjust our stories somewhat!

Source: arstechnica.com

Biggest Scientific Breakthroughs of 2013

center_universe2The new year is literally right around the corner, folks. And I thought what better way to celebrate 2013 than by acknowledging its many scientific breakthroughs. And there were so many to be had – ranging in fields from bioresearch and medicine, space and extra-terrestrial exploration, computing and robotics, and biology and anthropology – that I couldn’t possibly do them all justice.

Luckily, I have found a lovely, condensed list which managed to capture what are arguably the biggest hits of the year. Many of these were ones I managed to write about as they were happening, and many were not. But that’s what’s good about retrospectives, they make us take account of things we missed and what we might like to catch up on. And of course, I threw in a few stories that weren’t included, but which I felt belonged.

So without further ado, here are the top 12 biggest breakthroughs of 2013:

1. Voyager 1 Leaves the Solar System:

For 36 years, NASA’s Voyager 1 spacecraft has travelling father and farther away from Earth, often at speeds approaching 18 km (11 miles) per second. At a pace like that, scientists knew Voyager would sooner or later breach the fringe of the heliosphere that surrounds and defines our solar neighborhood and enter the bosom of our Milky Way Galaxy. But when it would finally break that threshold was a question no one could answer. And after months of uncertainty, NASA finally announced in September that the space probe had done it. As Don Gurnett, lead author of the paper announcing Voyager’s departure put it: “Voyager 1 is the first human-made object to make it into interstellar space… we’re actually out there.”

voyager12. The Milky Way is Filled with Habitable Exoplanets:

After years of planet hunting, scientists were able to determine from all the data gathered by the Kepler space probe that there could be as many as 2 billion potentially habitable exoplanets in our galaxy. This is the equivalent of roughly 22% of the Milky Way Galaxy, with the nearest being just 12 light years away (Tau Ceti). The astronomers’ results, which were published in October of 2013, showed that roughly one in five sunlike stars harbor Earth-size planets orbiting in their habitable zones, much higher than previously thought.

exoplanets23. First Brain to Brain Interface:

In February of 2013, scientists announced that they had successfully established an electronic link between the brains of two rats. Even when the animals were separated by thousands of kms distance, signals from the mind of one could help the second solve basic puzzles in real time. By July, a connection was made between the minds of a human and a rat. And by August, two researchers at the Washington University in St. Louis were able to demonstrate that signals could be transmitted between two human brains, effectively making brain-to-brain interfacing (BBI), and not just brain computer interfacing (BCI) truly possible.

brain-to-brain-interfacing4. Long-Lost Continent Discovered:

In February of this year, geologists from the University of Oslo reported that a small precambrian continent known as Mauritia had been found. At one time, this continent resided between Madagascar and India, but was then pushed beneath the ocean by a multi-million-year breakup spurred by tectonic rifts and a yawning sea-floor. But now, volcanic activity has driven the remnants of the long-lost continent right through to the Earth’s surface.

Not only is this an incredibly rare find, the arrival of this continent to the surface has given geologists a chance to study lava sands and minerals which are millions and even billions of years old. In addition to the volcanic lava sands, the majority of which are around 9 million years old, the Oslo team also found deposits of zircon xenocryst that were anywhere from 660 million to 1.97 billion years old. Studies of these and the land mass will help us learn more about Earth’s deep past.

mauritia5. Cure for HIV Found!:

For decades, medical researchers and scientists have been looking to create a vaccine that could prevent one from being infected with HIV. But in 2013, they not developed several vaccines that demonstrated this ability, but went a step further and found several potential cures. The first bit of news came in March, when researchers at Caltech demonstrated using HIV antibodies and an approach known as Vectored ImmunoProphylaxis (VIP) that it was possible to block the virus.

Then came the SAV001 vaccine from the Schulich School of Medicine & Dentistry at Western University in London, Ontario, which aced clinical trials. This was punctuated by researchers at the University of Illinois’, who in May used the “Blue Waters” supercomputer to developed a new series of computer models to get at the heart of the virus.

HIV-budding-ColorBut even more impressive was the range of potential cures that were developed. The first came in March, where researchers at the Washington University School of Medicine in St. Louis that a solution of bee venom and nanoparticles was capable of killing off the virus, but leaving surrounding tissue unharmed. The second came in the same month, when doctors from Johns Hopkins University Medical School were able to cure a child of HIV thanks to the very early use of antiretroviral therapy (ART).

And in September, two major developments occurred. The first came from Rutgers New Jersey Medical School, where researchers showed that an antiviral foot cream called Ciclopirox was capable of eradicating infectious HIV when applied to cell cultures of the virus. The second came from the Vaccine and Gene Therapy Institute at the Oregon Health and Science University (OHSU), where researchers developed a vaccine that was also able to cure HIV in about 50% of test subjects. Taken together, these developments may signal the beginning of the end of the HIV pandemic.

hiv-aids-vaccine6. Newly Discovered Skulls Alter Thoughts on Human Evolution:

The discovery of an incredibly well-preserved skull from Dmanisi, Georgia has made anthropologists rethink human evolution. This 1.8 million-year old skull has basically suggested that our evolutionary tree may have fewer branches than previously thought. Compared with other skulls discovered nearby, it suggests that the earliest known members of the Homo genus (H. habilis, H.rudolfensis and H. erectus) may not have been distinct, coexisting species, but instead were part of a single, evolving lineage that eventually gave rise to modern humans.

humanEvolution7. Curiosity Confirms Signs of Life on Mars:

Over the past two years, the Curiosity and Opportunity rovers have provided a seemingly endless stream of scientific revelations. But in March of 2013, NASA scientists released perhaps the most compelling evidence to date that the Red Planet was once capable of harboring life. This consisted of drilling samples out of the sedimentary rock in a river bed in the area known as Yellowknife Bay.

Using its battery of onboard instruments, NASA scientists were able to detect some of the critical elements required for life – including sulfur, nitrogen, hydrogen, oxygen, phosphorus, and carbon. The rover is currently on a trek to its primary scientific target – a three-mile-high peak at the center of Gale Crater named Mount Sharp – where it will attempt to further reinforce its findings.

mt_sharp_space8. Scientists Turn Brain Matter Invisible:

Since its inception as a science, neuroanatomy – the study of the brain’s functions and makeup – has been hampered by the fact that the brain is composed of “grey matter”. For one, microscopes cannot look beyond a millimeter into biological matter before images in the viewfinder get blurry. And the common technique of “sectioning” – where a brain is frozen in liquid nitrogen and then sliced into thin sheets for analysis – results in  tissue being deformed, connections being severed, and information being lost.

But a new technique, known as CLARITY, works by stripping away all of a tissue’s light-scattering lipids, while leaving all of its significant structures – i.e. neurons, synapses, proteins and DNA – intact and in place. Given that this solution will allow researchers to study samples of the brains without having to cut them up, it is already being hailed as one of the most important advances for neuroanatomy in decades.


9. Scientists Detect Neutrinos from Another Galaxy:

In April of this year, physicists working at the IceCube South Pole Observatory took part in an expedition which drilled a hole some 2.4 km (1.5 mile) hole deep into an Antarctic glacier. At the bottom of this hole, they managed to capture 28 neutrinos, a mysterious and extremely powerful subatomic particle that can pass straight through solid matter. But the real kicker was the fact that these particles likely originated from beyond our solar system – and possibly even our galaxy.

That was impressive in and off itself, but was made even more so when it was learned that these particular neutrinos are over a billion times more powerful than the ones originating from our sun. So whatever created them would have had to have been cataclysmicly powerful – such as a supernova explosion. This find, combined with the detection technique used to find them, has ushered in a new age of astronomy.

antarctic_expedition

10. Human Cloning Becomes a Reality:

Ever since Dolly the sheep was cloned via somatic cell nuclear transfer, scientists have wondered if a similar technique could be used to produce human embryonic stem cells. And as of May, researchers at Oregon Health and Science University managed to do just that. This development is not only a step toward developing replacement tissue to treat diseases, but one that might also hasten the day when it will be possible to create cloned, human babies.

cloning

11. World’s First Lab Grown Meat:

In May of this year, after years of research and hundred of thousands of dollars invested, researchers at the University of Maastricht in the Netherlands created the world’s first in vitro burgers. The burgers were fashioned from stem cells taken from a cow’s neck which were placed in growth medium, grown into strips of muscle tissue, and then assembled into a burger. This development may prove to be a viable solution to world hunger, especially in the coming decades as the world’s population increases by several billion.

labmeat112. The Amplituhedron Discovered:

If 2012 will be remembered as the year that the Higgs Boson was finally discovered, 2013 will forever be remembered as the year of the Amplituhedron. After many decades of trying to reformulate quantum field theory to account for gravity, scientists at Harvard University discovered of a jewel-like geometric object that they believe will not only simplify quantum science, but forever alters our understanding of the universe.

This geometric shape, which is a representation of the coherent mathematical structure behind quantum field theory, has simplified scientists’ notions of the universe by postulating that space and time are not fundamental components of reality, but merely consequences of the”jewel’s” geometry. By removing locality and unitarity, this discovery may finally lead to an explanation as to how all the fundamental forces of the universe coexist.

amplutihedron_spanThese forces are weak nuclear forces, strong nuclear forces, electromagnetism and gravity. For decades, scientists have been forced to treat them according to separate principles – using Quantum Field Theory to explain the first three, and General Relativity to explain gravity. But now, a Grand Unifying Theory or Theory of Everything may actually be possible.

13. Bioprinting Explodes:

The year of 2013 was also a boon year for bioprinting – namely, using the technology of additive manufacturing to create samples of living tissue. This began in earnest in February, where a team of researchers at Heriot-Watt University in Scotland used a new printing technique to deposit live embryonic stem cells onto a surface in a specific pattern. Using this process, they were able to create entire cultures of tissue which could be morphed into specific types of tissue.

Later that month, researchers at Cornell University used a technique known as “high-fidelity tissue engineering” – which involved using artificial living cells deposited by a 3-D printer over shaped cow cartilage – to create a replacement human ear. This was followed some months later in April when a San Diego-based firm named Organova announced that they were able to create samples of liver cells using 3D printing technology.


And then in August, researchers at Huazhong University of Science and Technology were able to use the same technique create the world first, living kidneys. All of this is pointing the way towards a future where human body parts can be created simply by culturing cells from a donor’s DNA, and replacement organs can be synthetically created, revolutionizing medicine forever.

14. Bionic Machinery Expands:

If you’re a science buff, or someone who has had to go through life with a physical disability, 2013 was also a very big year for the field of bionic machinery. This consisted not only of machinery that could meld with the human body in order to perform fully-human tasks – thus restoring ambulatory ability to people dealing with disabling injuries or diseases – but also biomimetic machinery.

ArgusIIThe first took place in February, where researchers from the University of of Tübingen unveiled the world’s first high-resolution, user-configurable bionic eye. Known officially as the “Alpha IMS retinal prosthesis”, the device helps to restore vision by converted light into electrical signals your retina and then transmitted to the brain via the optic nerve. This was followed in August by the Argus II “retinal prosthetic system” being approved by the FDA, after 20 years of research, for distribution in the US.

Later that same month, the Ecole Polytechnique Federale de Lausanne in Switzerland unveiled the world’s first sensory prosthetic hand. Whereas existing mind-controlled prosthetic devices used nerve signals from the user to control the movements of the limb, this new device sends electrostimulus to the user’s nerves to simulate the sensation of touch.

prosthetic_originalThen in April, the University of Georgia announced that it had created a brand of “smart skin” – a transparent, flexible film that uses 8000 touch-sensitive transistors – that is just as sensitive as the real thing. In July, researchers in Israel took this a step further, showing how a gold-polyester nanomaterial would be ideal as a material for artificial skin, since it experiences changes in conductivity as it is bent.

15. 400,000 Year-Old DNA Confuses Humanity’s Origin Story:

Another discovery made this year has forced anthropologist to rethink human evolution. This occurred in Spain early in December, where a team from the Max Planck Institute for Evolutionary Anthropology in Leipzig, Germany recovered a 400,000 year-old thigh bone. Initially thought to be a forerunner of the Neanderthal branch of hominids, it was later learned that it belonged to the little-understood branch of hominins known as Denisovans.

Human-evoThe discordant findings are leading anthropologists to reconsider the last several hundred thousand years of human evolution. In short, it indicates that there may yet be many extinct human populations that scientists have yet to discover. What’s more, there DNA may prove to be part of modern humans genetic makeup, as interbreeding is a possibility.