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  • richardmitnick 8:52 am on June 21, 2016 Permalink | Reply
    Tags: , , CosmosUp, , Why Doesn't Venus Have Water? Blame Electric Wind   

    From CosmosUp: “Why Doesn’t Venus Have Water? Blame Electric Wind” 

    CosmosUp bloc

    CosmosUp

    21, Jun 2016
    No writer credit found

    Venus, our nearest neighbor, is one of the most inhospitable places in the solar system, it’s surface is often said to resemble the classical images of Hell, a really awful place that will kill you in less than 10 seconds.

    Right now, Venus is more than 800°F (426&deg:C) on a normal day, that is hot enough to melt lead; with an atmosphere composed primarily of carbon dioxide (96.5%) — about 90 times denser than Earth’ is — and much higher surface atmospheric pressure, Venus is a place of extremes, definitely not a friendly planet for humanity.

    But at some point in the past, more than 4 billion years ago, Venus wasn’t a desolate wasteland but actually a cool place as some scientists believe.

    Venus is often thought of as Earth’s twin sister because of its size, mass and gravity and there’s evidence that once it contained oceans of water.

    But, as the surface’ temperature of the planet rose to 470°C, all the water boiled away presumably as vapor, into the atmosphere.

    Nowadays, the atmosphere of the planet has 10,000 to 100,000 times less water than Earth’s atmosphere.. Something had to remove all that steam, so where is that water today?

    Previous studies theorized that the solar wind as the likely suspect, but now, a new research reveal that Venus is far more hellish than we previously thought.

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    Venus is the planet most like Earth in terms of its size and gravity, and evidence suggests it once had oceans of water that boiled away to steam long ago, with surfaces temperatures of around 460°C (860°F)

    Electric Wind to blame?

    According to a new study published in the journal Geophysical Research Letters, unexpectedly strong electric wind sucked oxygen out into space, thus stripped Venus of its oceans.

    “We found that the electric wind, which people thought was just one small cog in a big machine, is in fact this big monster that’s capable of sucking the water from Venus by itself,

    said Glyn Collinson.

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    When water molecules rise into the upper atmosphere, sunlight breaks the water into hydrogen ions

    It’s amazing, shocking,

    added Collinson

    We never dreamt an electric wind could be so powerful that it can suck oxygen right out of an atmosphere into space. This is something that has to be on the checklist when we go looking for habitable planets around other stars.”

    Just as every planet has a gravity field, the force that holds together everything in the universe, some scientists suspect that every planet with an atmosphere is also surrounded by a weak electric field.

    While the force of gravity is responsible of holding down the atmosphere of the planet, the electric force can help to push the upper layers of the atmosphere off into space.

    So far, we have not been able to detect it even in our own planet, but scientists believe its there, but these electric fields are very, very weak.

    Venus is different. Its electric field is enormous, so strong that it can accelerate even the heavier ions to speeds fast enough to escape the planet’s gravity.

    “If you were unfortunate enough to be an oxygen ion in the upper atmosphere of Venus then you have won a terrible, terrible lottery.”

    said Collinson.

    Hunting for other worlds

    These new results may have implications and information that could help us to understand other worlds around the solar system and beyond.

    “We’ve been studying the electrons flowing away from Titan [a moon of Saturn] and Mars as well as from Venus, and the ions they drag away to space,”

    said Andrew Coates, who leads the electron spectrometer team at University College London in the U.K.

    Astronomers will also have to take the electric field of a planet into account when trying to figure out a star’s habitable zone

    “Even a weak electric wind could still play a role in water and atmospheric loss at any planet,

    co-author on the study Alex Glocer said in the statement.

    It could act like a conveyor belt, moving ions higher in the ionosphere where other effects from the solar wind could carry them away.”

    See the full article here .

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  • richardmitnick 9:41 am on June 8, 2016 Permalink | Reply
    Tags: , , CosmosUp,   

    From CosmosUp: “Hunting Extraterrestrial Life On Exomoons” 

    CosmosUp bloc

    CosmosUp

    08, Jun 2016
    No writer credit found

    In the past two decades, astronomers have detected more than 2000 exoplanets, the first of these detections were gas giants as massive as Jupiter that are so close to the host that they are heated to high temperature in order of 2,000°C; but now, for the first time, astronomers are getting down to the regime of potentially habitable Earth-like worlds.

    The goal of space exploration has always been the same, to try to answer the oldest scientific question: are we alone in the universe?

    Why limit ourselves to exoplanets? The search for alien life doesn’t end with them; Increasingly, astrobiologists watch the moons in our own solar system for the hint of biology, if the so-called exomoons can also have potential life then it will be more habitable moons than planets within the cosmos.

    But first, just as a reminder: an exomoon is simply a moon which orbits an exoplanet and remember, an exoplanet is a planet which orbits other star than the sun, so these exomoons are just moons going around planets around stars other than the sun.

    So far, we haven’t discovered and confirmed exomoons but we know thousands of exoplanets, so we are sure exomoons are there, we simply lack the sensitivity to detect them — to date, there are only three exomoon candidates.

    Exomoons’ idea is really interesting, there is no reason why you couldn’t have an Earth-like world as moon going around a massive planet as Jupiter and, don’t forget, exomoons doesn’t depend on how far away from the heat of their star they are.

    Remember the world of Pandora in the epic movie Avatar? Well, that wasn’t an exoplanet, it was in fact a moon orbiting a massive exoplanet.

    Our solar system has some fascinating moons orbiting Jupiter and Saturn that, may not look like the SF rain-forest moon of Pandora, but they do have vast sub-surface oceans beneath their frozen crusts — the water is heated to a liquid by tidal forces squeezing the insides of the moon creating a heat source — no sunlight required!

    “Moons have separate energy sources,

    René Heller, an astrophysicist at the Origins Institute at McMaster University, said.

    While the habitability of terrestrial planets is mostly determined by stellar illumination, moons also receive reflected stellar light from the planet as well as thermal emission from the planet itself.”

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    The first challenge in studying exomoons is to actually find one. For detection, current techniques mostly focus on light curve analysis. The concept is that the exomoon alters the light curve in a specific and identifiable way.

    Other methods also have been proposed, such as direct imaging, radial velocity measurements, microlensing, or pulsar timing.

    Today, scientists use Kepler to search for moons orbiting alien planets, with a project called the Hunt for Exomoons with Kepler (HEK), the first systematic search for exomoons. Astronomers simulate billions of possible star-planet-moon arrangements using NASA’s Pleiades Supercomputer.

    NASA Advanced Supercomputing Center Pleiades Supercomputer
    NASA SGI Advanced Supercomputing Center Pleiades Supercomputer

    They then compare the results with actual data taken with Kepler telescope, if one of the simulated combinations matches the Kepler data, that area warrants further exploration.

    “For each planet where we don’t discover an exomoon, we are able to say how massive a moon is excluded by the current data, telling us about our sensitivity,

    said David Kipping at the Harvard-Smithsonian Center for Astrophysics, lead astronomer of HEK.

    Signs of life on an exomoon could be as simple as some form of primitive biology. And life on one moon could mean life on many more. If such habitable moons are possible, then there could even be more habitable moons than habitable planets.”

    New perspective for alien life on exomoons

    Occultation light curves of exomoons may give information on their albedo, or reflection coefficient, and hence indicate the presence of ice cover on the surface. Icy moons might have subsurface oceans thus these may potentially be habitable.

    In a new work, uploaded on arxiv servers, astronomers applied some simple calculations for different stellar masses and compared the flux drop caused by the moon’s occultation and thus they found that the albedo estimation by their method is not feasible for moons of solar-like stars, but small M dwarfs are better candidates for such measurements.

    Although most search projects focus on solar-like stars, M dwarfs as targets should also be considered, because of more than 70% of the stars are of M spectral type.

    But in theory, red dwarf stars, which are smaller and cooler than the sun, tend not to produce particularly massive gas giant planets so it is possible that no large exomoons are present around them.

    But based on the discovered exoplanets currently 68 M dwarfs are known to have 96 exoplanets, from which the heaviest planet’s mass is 62 Jupiter masses (Mj), 20 other exoplanets have at least 10 Jupiter-masses, and there are 13 other planets that are heavier than 1 MJ (source: exoplanet.eu, January 2016). So, the average mass of the exoplanets of the 68 M dwarfs is 4.8 MJ.

    Moons of smaller stars seem to be easier to detect, if their stellar distance is smaller. In addition, the smaller the star, the closer the snowline located, meaning that rocky bodies can stay icy even if they are orbiting the star in a closer orbit.

    The vicinity to the star makes the body brighter, thus an icy exomoon is easier to detect in occultation close to the snowline of an M dwarf, than at the snowline of a solar-like star.

    So, based on these observations, astronomers assume that geometric albedo above around 0.7 (for reference, Europa with 1.02 and Enceladus with 1.38 geometric albedo) indicates some ice, often water ice, with relatively young surface, and higher albedo might suggest freshly fallen water ice crystals — thus may potentially be habitable or at least could be considered as favorable environments for life.

    “We predict that the first albedo estimations of exomoons will probably be made for large icy moons around the snowline of M type main sequence stars.”

    concluded astronomers.

    With the next generation of telescopes expected soon to be launched, the exomoons might not be able to hide for much longer.

    See the full article here .

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  • richardmitnick 11:47 am on May 31, 2016 Permalink | Reply
    Tags: , , CosmosUp, HD140283 or Methuselah Star   

    From CosmosUp: “HD140283 or Methuselah Star: The Object that Baffles Scientists’ 

    CosmosUp bloc

    CosmosUp

    31, May 2016

    In the constellation Libra about 190 light years away from our planet, reside one of the most mysterious objects in our galaxy, the impossible star which appears to be older than the universe itself.

    This Methuselah star, cataloged as HD 140283, is a metal poor sub-giant star, neither on the main sequence nor a red giant, has been known to astronomers for more than 100 years as a high-velocity star — it cruises across the sky at a relatively rapid clip.

    HD 140283 moves through our galactic neighborhood at astonishing speed of 800,000 mph (1.3 million km/h) relative to our solar system; with such speed, its cover the width of the full moon in the sky every 1,500 years or so.

    This high rate of motion is evidence that the star is just passing through our region of space thus it will eventually rocket back out to our galaxy’s halo — the region of space where the Milky Way’s oldest stars reside.

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    The Methuselah star catch our attention back in 2000 when a team of scientists calculate its age and got a shocking result, the stars appeared to be 16 billion years old, which is more than two billion years older than the universe.

    This is an absurdity, obviously somebody’s got something wrong here, and it’s almost certainly the age of Methuselah star, not our supposed age of the Universe, which is measured to be 13.78 ± 0.037 billion years old. But here’s a surprise!

    In 2014, A team of astronomers using NASA’s Hubble Space Telescope refine the distance to HD 140283 and estimated its age: Methuselah star could be as old as (14.5 ± 0.8) billion years, that, barely, gets the star into the realm of being possible — it still older than the universe, which is a dilemma for cosmologists.

    ” We have found that this is the oldest known star with a well-determined age,

    said Howard Bond.

    Maybe the cosmology is wrong, stellar physics is wrong, or the star’s distance is wrong. So we set out to refine the distance.”

    So, the question is what did we do wrong? Well, there are still many things that we do not know about star formation and their aging process and everyone is confident that HD 140283 is not, in fact, older than the Universe.

    But what we are pretty sure, the Methuselah star is one of the elder statesmen of the universe. Considering the uncertainty of 800 million years, the star could be as young as 13.6 billion years, which is within the age of the universe.

    The extreme age of this star is nonetheless fascinating and can tell us many interesting things: it is likely that HD 140283 formed when the universe was less than 170 million years old and it’s a second generation star.

    The first stars in the universe were the so called population III stars, stars believed to have formed from the primordial “molecular” clouds, 100 million years after the Big Bang.

    These stars were super-giant stars — 100 to 1,000 times more massive than the Sun, hot and bright, exploding as supernovae after only about 2 million years. Population III stars produced and dispersed the first heavy elements, paving the way for the eventual formation of pop II stars.

    Methuselah must have been of the second generation of stars, and its age being so close to the birth of the Universe indicates that the space between the formation of the first and second generations of stars was only a few tens of millions of years.

    explained scientists.

    Is Methuselah Star the oldest star in the universe?

    Well, we don’t know but after six months (2014) when the media told us about HD 140283, the “Methuselah Star”, Australian scientists announced the discovery of SMSS J031300.36-670839.3, an easy name to catch, a star at a distance of 6000 light years from Earth, with an age of approximately 13.6 billion years, the oldest star ever seen in the Universe.

    This latest discovery, of SMSS J031300.36-670839.3, may be the oldest star we know in the universe, but given the uncertainties involved, maybe it isn’t, nobody knows for certain.

    At this moment, HD 140283 is one of the oldest known stars in the Universe, and while that’s not quite as impressive as being older than the Universe, it’s still a pretty cool superlative.

    See the full article here .

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  • richardmitnick 1:08 pm on May 30, 2016 Permalink | Reply
    Tags: , , CosmosUp, , The Promise of Kepler-62f: A Distant Earth-like World   

    From CosmosUp: “The Promise of Kepler-62f: A Distant Earth-like World” 

    CosmosUp bloc

    CosmosUp

    30, May 2016

    On April 18, 2013, NASA’ astronomers announced the discovery of a new planetary system composed of five worlds orbiting a star somewhat cooler and smaller than the Sun, approximately 1,200 light-years away from us in the constellation Lyra.

    The outermost of them, named Kepler-62f, looks hopeful for supporting life. Around 40% larger than our planet, Kepler-62f is likely a solid planet within the star’s habitable zone, where conditions may be just right for liquid water to form.

    Giving its good shape and size, the unique planet may even possess surface oceans, but back then, NASA’s Kepler mission failed to gather sufficient information about Kpler-62f’ composition, atmosphere or orbit.

    At that size, Kepler-62f is within the range of planets that are likely to be rocky and possibly could have oceans,

    said Aomawa Shields, lead author of the study published* in the May 13 issue of the journal Astrobiology.

    So, to determine whether Kepler-62f could harbor life, Aomawa Shields ran computer simulations and thus came up with various scenarios of possible atmospheric conditions and orbital shape of the planet.

    “We found there are multiple atmospheric compositions that allow it to be warm enough to have surface liquid water. This makes it a strong candidate for a habitable planet.”

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    Kepler 62f. NASA

    NASA/Kepler Telescope
    NASA/Kepler Telescope

    On Earth, carbon dioxide makes up about 0.04% of the atmosphere. Because Kepler-62f is much farther from its parent star than Earth is to the Sun, it would need a thick carbon dioxide-rich atmosphere to stop its water from freezing — it needs to have three to five times a thicker atmosphere than the Earth’s in order to be considered consistently habitable during the entire year.

    But, what if the carbon-dioxide levels are low or closer to those found on Earth? Shields estimated the temperature on the planet rises above freezing during certain times of the year which may result in melting of the ice sheets to form liquid water – enough to sustain life.

    Though astronomers don’t know for sure whether life could exist on Kepler-62f, but Dr Shields is optimistic about finding life in the universe.

    “This technique will help us understand how likely certain planets are to be habitable over a wide range of factors, for which we don’t yet have data from telescopes,

    she said.

    And it will allow us to generate a prioritized list of targets to follow up on more closely with the next generation of telescopes that can look for the atmospheric fingerprints of life on another world.”

    Kepler-62f and Kepler’ Legacy

    To date, NASA’ Kepler Telescope has discovered more than 2300 exoplanets and more than twice are as-yet unconfirmed planetary candidates, but only few are considered to belong in the “habitable zone” — the range of orbits around a star within which a planetary surface can support liquid water.

    The most habitable planet to date is Kepler-452b but it is located 1,400 light-years away from us, so unless we invent a way of prolonging our lives drastically, it might remain a pipe dream for now.

    But there are others relatively close planets to us that could be habitable, like Gliese 581d which is just 20 light years away; who knows, maybe soon we could detect exoplanets even closer than Gliese 581d, maybe there’s a planet in Alpha Centauri star system waiting for us to be discovered, or within the range of 10 ly from us.

    Whether or not intelligent life actually exists in our universe, we know for sure there is life out there and we are getting closer and closer to find it.

    Science paper:
    The Effect of Orbital Configuration on the Possible Climates and Habitability of Kepler-62f

    See the full article here .

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  • richardmitnick 10:21 am on May 29, 2016 Permalink | Reply
    Tags: , , CosmosUp, , There's a Giant Coronal Hole In the Sun Right Now   

    From CosmosUp: “There’s a Giant Coronal Hole In the Sun Right Now” 

    CosmosUp bloc

    CosmosUp

    29, May 2016

    This week, NASA’ Solar Dynamics Observatory (SDO) captured a remarkable phenomenon on the sun’s surface, a giant hole known as coronal hole taking up more than 10% of our sun’s surface.

    NASA/SDO
    NASA/SDO

    From here, our sun seems eerily calm but it is actually a red-hot ball of violence capable of spewing powerful blasts of radioactive particles towards Earth.

    These powerful blast could be extremely dangerous, messing up with our communication systems and satellites and would be dangerous to unshielded astronauts, large doses could be even fatal; thankfully, Earth’s magnetosphere is there to keep us safe — these blast cannot harm our human bodies as long as we remain on the surface of Earth.

    Magnetosphere of Earth, original bitmap from NASA. SVG rendering by Aaron Kaase
    Magnetosphere of Earth, original bitmap from NASA. SVG rendering by Aaron Kaase

    So, what causes these violent streams? The solar wind emanates from the Sun in all directions, but one of the sun’ lesser-known weather phenomena, called coronal holes, emanate most readily these stream of particles.

    Coronal holes are low-density regions of the sun’s atmosphere known as the corona – the aura of plasma surrounding the sun,

    explained NASA scientists.

    Because they contain little solar material, they have lower temperatures and thus appear much darker than their surroundings. Coronal holes are visible in certain types of extreme ultraviolet light, which is typically invisible to our eyes, but is colorized here in purple for easy viewing.
    Such phenomenon are being investigated by NASA’ Solar Dynamics Observatory, a spacecraft launched on February 11, 2010, that scientists use to understand the causes of solar variability and its impacts on Earth.

    From May 17-19, SDO spotted a colossal coronal hole covering the northern hemisphere of our star, so huge that scientists aren’t quite sure how to explain it, but it is clear that the sun is going through something very strange; this is the first time such a massive hole has been found or at least captured on the video, let’s take a look:

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    In this image, you can see something very unusual is happening with our sun, something that we have yet to fully understand; usually holes have been seen but nothing at the size of the whole recently found.

    Though NASA says the recent holes in our sun, even the large ones like this one, is actually not of great concern, it is totally normal but some researchers said that something is clearly happens with our sun, such large hole have never seen before.

    So, guys what do you think? Is our sun is going dark? Or NASA is telling us the truth and we have nothing to worry about?

    2

    See the full article here .

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  • richardmitnick 8:25 am on May 29, 2016 Permalink | Reply
    Tags: , , CosmosUp,   

    From CosmosUp: “May 30: Mars to Make The Closest Approach to Earth In 11 Years” 

    CosmosUp bloc

    CosmosUp

    27, May 2016
    Editors

    Don’t miss!!! On Monday, May 30, Mars will be closer to Earth than it has been in 11 years and it will shine 10 times brighter than it did at the start of 2016.

    1
    2016 – Planet MARS

    Last week on May 22, Mars reached opposition with the sun, meaning the Earth was between Mars and the Sun, but that phenomena did not mark Mars’ closest approach to Earth. On May 30, Mars Will be 47.2 million miles (75.3 million kilometers) from Earth, that’s more than 500,000 miles closer to our planet than at opposition.

    So, it is a great opportunity to stargazer to catch a glimpse of Mars as will appear bigger and brighter than usual to us until June 3.

    Mars is easy to view with the naked eye, you don’t need a telescope or binoculars to see it, probably you will be able to find it easily without a star chart or an astronomy app.

    “The size of Mars varies more than any other planet, and we’ve waited a full decade for it to come this close and appear this large,

    said Slooh astronomer Bob Berman in a statement.

    Throw in the fact that it’s the only other planet on which humans will ever walk and you can understand why everyone will be turning in to this rare occasion.”

    In 2018, the next time their orbits line up, Mars and the Earth will be even closer, 36 million miles. The modern-day record, 34.6 million miles, was set in 2003. That won’t be surpassed until the year 2287 – that was the nearest Earth and Mars have been in almost 60,000 years according to NASA.

    “I observed (Mars) through quite a small five inch reflecting telescope at the beginning of the month and could see a surprising amount of detail.”

    Robin Scagell, vice-president of the Society for Popular Astronomy, said to skynews.

    Mars is now quite large in the sky, about 18 seconds of arc across (0.3 degrees). It looks very red because it’s so low in the sky, scraping the rooftops really.

    If you want to see some detail you need a telescope with 75 – 100 times magnification. The best time to see it is around 1am. Saturn is next to Mars at the moment and you can see the difference between the two planets. Saturn looks yellowish.

    Don’t miss this close approach of Mars thus you’ll have to wait until July of 2018 !!!

    1

    See the full article here .

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  • richardmitnick 1:53 pm on May 26, 2016 Permalink | Reply
    Tags: , , CosmosUp, Gliese 581d   

    From CosmosUP: “Gliese 581d: Earth-like World Within Our Reach” 

    CosmosUp bloc

    CosmosUp

    25, May 2016
    NASA astronomers said they’ve discovered a planet that they believe has a 100% chance of having life on it and its relatively close to us, just in our cosmic neighborhood — meet Gliese 581d.

    Gliese 581 is a red dwarf star located about 20 light-years away from Earth in the constellation Libra — One light-year is about 6 trillion miles (10 trillion km); Out of the billions of stars in the sky, Gliese 581 is the 89th closest known star to the Sun.

    In 2005, astronomers found six exoplanets orbiting their star in nearly circular paths and they were named as Gliese b, c, d, f and g; they used the indirect method to found these planets, which mean that the planets cannot be viewed with a telescope; Astronomers used radial velocity data on the star. This method looks at a star’s tiny movements due to the gravitational tug from orbiting bodies. The subtle tugs let researchers estimate the planet’s mass and how long it takes to circle its star.

    It was calculated that Gliese 581d is in the perfect not-too-hot not-too-cold Goldilocks zone, just the ideal distance away from the start to be able to support life; in fact, some astronomers are 100% certain that they do:

    “Personally, given the ubiquity and propensity of life to flourish wherever it can, I would say, my own personal feeling is that the chances of life on this planet are 100 percent,

    said Steven Vogt, a professor of astronomy and astrophysics at the University of California, Santa Cruz.

    I have almost no doubt about it.”

    But are we sure abut this planet? Well, many so called habitable exoplanets have been found and later discredited so there’s still a chance that further observations will dismiss this planet. Actually, in 2014 there was a study that claimed the super-Earth planets GJ 581d does not exist, but is actually an artifact of noise and stellar activity, but reanalysis suggests that it does in fact exist, despite stellar variability.

    Gliese 581d’ mass is thought to be 6.98 Earths and its radius is thought to be 2.2 Earth’s radius. It is considered to be a super-Earth with a solid surface allowing for any water present on its surface to form liquid oceans and an atmosphere and even landmasses characteristic of Earth’s surface.

    “The Gliese system is particularly exciting to us as it’s very close to Earth, relatively speaking. So with future generations of telescopes, we’ll be able to search for life on Gliese 581d directly.”

    said Robin Wordsworth.

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    Gliese 581d is a key target for the upcoming James Webb Space Telescope (JWST). The infrared James Webb Space Telescope (JWST), due to launch in 2018, is predicted to dramatically change our understanding of exoplanet atmospheres.

    JWST might provide the atmospheric data for Gliese 581d and determine whether this planet may be in the liquid water habitable zone of its star and thus if its capable of supporting life.

    “This technology we are using to explore exoplanets is real,

    added John Grunsfeld, astronaut and associate administrator for NASA’s Science Mission Directorate.

    The James Webb Space Telescope and the next advances are happening now. These are not dreams — this is what we do at NASA.”

    NASA/ESA/CSA Webb Telescope annotated
    “NASA/ESA/CSA Webb Telescope annotated
    “It’s within our grasp to pull off a discovery that will change the world forever,

    he said in a statement.

    Just imagine the moment, when we find potential signatures of life. Imagine the moment when the world wakes up and the human race realizes that its long loneliness in time and space may be over – the possibility we’re no longer alone in the Universe.”

    Since its discovery, a massive campaign went into beaming a message from Earth to Gliese system including over 500 messages selected from over half a million entries, using the RT-70 radar telescope of Ukraine’s National Space Agency.

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    RT-70 radar telescope of Ukraine’s National Space Agency

    Gliese 581d a World of possibilities

    Could this actually be our closest life supporting neighbor… only 20 light years away? If so, what might life there be like?

    “Any discussion about alien life on Gliese 581g is purely speculative at this point,

    according to co-discoverer Paul Butler of the Carnegie Institution of Washington.

    But anywhere you find water on Earth, you find life. A similar condition should hold for almost anywhere in the universe, including Gliese 581g if it does hold water.”

    Beside this planet, scientists estimates that there are tens of billions of potentially habitable planets may exist, waiting to be found.

    “I would venture to say that most of my colleagues here today say it is improbable that in the limitless vastness of the Universe we humans standalone.”

    See the full article here .

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    • Richard Mallett 5:31 pm on June 15, 2016 Permalink | Reply

      The article starts off talking about 581d and then starts talking about 581g. AFAIK they are both potentially habitable if they exist.

      Liked by 1 person

    • richardmitnick 3:02 pm on June 16, 2016 Permalink | Reply

      Please define “AFAIK”.

      Like

    • Richard Mallett 12:22 pm on June 19, 2016 Permalink | Reply

      ‘As far as I know’ in this context means that Wikipedia says that “Gliese 581 g is thought to be in the middle of the habitable zone.” and “Analysis suggests that it [Gliese 581 d] orbits within the star’s habitable zone, where the temperatures are just right to support life.”

      Liked by 1 person

  • richardmitnick 12:23 pm on May 17, 2016 Permalink | Reply
    Tags: , , CosmosUp, Red Giant Stars Could Host Exoplanets With Alien Life   

    From CosmosUp: “Red Giant Stars Could Host Exoplanets With Alien Life” 

    CosmosUp bloc

    CosmosUp

    17, May 2016

    Everything in the universe comes to an end, and our sun is no exception. In five billion years from now, the sun will become a huge orange giant star, so large that it will engulf the orbits of Mercury and Venus.

    In this dramatic process, the Earth will not survive the sun’s expansion, it will no longer be within the habitable zone. It’ll be the end for life on Earth but don’t worry, our solar system could give us a second chance.

    In the new paper* published in Astrophysical Journal, astronomers Ramses Ramirez and Lisa Kaltenegger, from Cornell’s Carl Sagan Institute, suggest that when giant stars begin to die out, they could warm up frozen planets enough to have liquid water on their surface.

    “When a star ages and brightens, the habitable zone moves outward and you’re basically giving a second wind to a planetary system,

    said lead author Ramirez.

    Currently objects in these outer regions are frozen in our own solar system, and Europa and Enceladus — moons orbiting Jupiter and Saturn — are icy for now.”

    1
    © CosmosUp

    “Long after our own plain yellow Sun expands to become a red giant star and turns Earth into a sizzling hot wasteland, there will still be regions in our solar system — and other solar systems as well — where life might thrive,”

    said Kaltenegger.

    Red giant stars demise is a New Beginning

    Some red giant stars, smaller mass stars, in the universe remain that way for billions of years, in some cases, they still red giants even 9 billion years; so planets can remain habitable around these stars twice Earth’s current age. That’s sufficiently long for life to form from scratch, or to flourish in a newer, more welcoming environment.

    “This is basically breaking the idea that habitable means stars like our own, and suns with ages like our own,”

    Kaltenegger said.

    “We’re basically providing observers with a navigational map of the habitable zone for any star,” he said. “It’s a tool for finding all potentially habitable planets.

    In the far future, a distant frozen world like Saturn’ moon Enceladus could become habitable around our suns for billions of years, maybe even starting life, just like on Earth. That makes me very optimistic about the chances for life in the long run,”

    said Kaltenegger.

    2

    In their study, the team has already identified 23 red giant stars within 100 light-years of Earth, and a hundred more that are close to the red giant phase; which could be warming up new habitats for life as we speak.

    “It would be fascinating to discover signatures of a life on a world that we knew had to be completely frozen initially, but that is now within the evolved habitable zone,

    Kaltenegger said.

    That would, in a way, help answer the question of whether you could have life in a subsurface ocean. No matter what we find on Europa and Enceladus, it’ll be a really interesting part of the puzzle.”

    *Science paper:
    Habitable Zones of Post-Main Sequence Stars

    See the full article here .

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  • richardmitnick 5:51 pm on May 12, 2016 Permalink | Reply
    Tags: , , CosmosUp,   

    From CosmosUp: “[Info and Images] The Crab Pulsar And Its Nebula” New Take on an Old Subject, Worth Your Time 

    CosmosUp bloc

    CosmosUp

    The Crab Pulsar was born with supernova explosion which was widely observed on Earth in the year 1054. The Crab Nebula is located 6,500-light-years away from us in the direction of Constellation Taurus. Here, in this article, we will present this amazing object, once thought to be the most energetic light in universe.

    A brief history of stars

    When a massive star, with a mass several times that of the Sun, reach the end of its live, it compresses and explodes as supernovae, leaving behind a good-looking corpse, a neutron star. Neutron stars are the smallest and densest stars known to exist in the Universe.

    1

    They are only a few miles across, with a large fraction of the star’s original mass, composed almost entirely of neutrons — subatomic particles with no net electrical charge. Neutron stars are very hot and spins spectacularly fast on its axis emitting beams of electromagnetic radiation that are detected as pulsars.

    The Crab Nebulae

    After a massive explosion powerful enough to turn a huge star into cloud of dust, the crab nebula took shape- the eye of the storm, a speeding pulsating star, a pulsar. The gravity squeezed the giant star’s core into an object with 10km diameter, rotating 30 times per second.

    Scientists estimate the crab pulsar’s mass to that of 1.5 solar masses. It’s so dense that one pint of this will weigh thousands maybe millions of tons. Two beams of light, energy and radiation, spinning 30 time per second power the huge cloud of dust, the crab nebula.

    There’s so much radiations there, more even on the Sun, that’s could easily be considered one of the deadliest things in the universe.

    2
    Chandra image of the Crab Nebula

    3
    Crab Nebula in Multiple Wavelengths
    Based on File:Crab Nebula in multiwavelength.png by Torres997

    The Crab Pulsar

    In Jan 2016 MAGIC, a ground-based gamma-ray instrument located on the Canary island of La Palma, Spain, discovered unexpected very energetic photons, the most energetic pulsed emission radiation ever detected to date coming from the center of the supernova of 1054 A.D., the Crab pulsar.

    MAGIC Cherenkov gamma ray telescope
    MAGIC Cherenkov gamma ray telescope on the Canary island of La Palma, Spain

    “We performed deep observation of the Crab pulsar with MAGIC to understand this phenomenon, expecting to measure the maximum energy of the pulsating photons,”

    Roberta Zanin from (ICCUB-IEEC, Barcelona) continues:

    The new observations extend this tail to much higher, above TeV energies, that is, several times more energetic than the previous measurement, violating all the theory models believed to be at work in neutron stars.”

    4
    Crab pulsar, astro.uu.nl/ jleeuwen

    6
    This is a mosaic image, one of the largest ever taken by NASA’s Hubble Space Telescope of the Crab Nebula, a six-light-year-wide expanding remnant of a star’s supernova explosion. Japanese and Chinese astronomers recorded this violent event nearly 1,000 years ago in 1054, as did, almost certainly, Native Americans.

    The orange filaments are the tattered remains of the star and consist mostly of hydrogen. The rapidly spinning neutron star embedded in the center of the nebula is the dynamo powering the nebula’s eerie interior bluish glow. The blue light comes from electrons whirling at nearly the speed of light around magnetic field lines from the neutron star. The neutron star, like a lighthouse, ejects twin beams of radiation that appear to pulse 30 times a second due to the neutron star’s rotation. A neutron star is the crushed ultra-dense core of the exploded star.

    The Crab Nebula derived its name from its appearance in a drawing made by Irish astronomer Lord Rosse in 1844, using a 36-inch telescope. When viewed by Hubble, as well as by large ground-based telescopes such as the European Southern Observatory’s Very Large Telescope, the Crab Nebula takes on a more detailed appearance that yields clues into the spectacular demise of a star, 6,500 light-years away.
    The newly composed image was assembled from 24 individual Wide Field and Planetary Camera 2 exposures taken in October 1999, January 2000, and December 2000. The colors in the image indicate the different elements that were expelled during the explosion. Blue in the filaments in the outer part of the nebula represents neutral oxygen, green is singly-ionized sulfur, and red indicates doubly-ionized oxygen.

    See the full article here .

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  • richardmitnick 8:15 am on May 8, 2016 Permalink | Reply
    Tags: , , CosmosUp,   

    From CosmosUp: “A Nearby Supernovae Stripped Mars Atmosphere” 

    CosmosUp bloc

    CosmosUp

    08, May 2016
    Editors

    Today’ Mars is very cold, very dry and very inhospitable, practically a dead place but this wasn’t always the case, things were very different in the ancient past. Scientists believe early Mars had a substantial atmosphere in the past than it does today, an atmosphere much more similar to Earth’s.

    More than 3.6 billion years ago, climatic conditions appear to have been favorable for the presence of liquid water on Mars’ surface, this in turn gave rise to speculation that Mars was capable of supporting life and even a home to a native civilization.

    But over time, the Red Planet lost most of its carbon dioxide-dominated atmosphere; this atmospheric loss led to depressurization and cooling, and is thought to be the primary driving force responsible for the loss of liquid water from its surface.

    “We think that all of the action took place between about 4.2 to 3.7 billion years ago,”

    MAVEN principal investigator Bruce Jakosky, said.

    NASA/Mars MAVEN
    NASA/Mars MAVEN

    The present atmospheric surface pressure is about 6 millibars on an average, which is about 0.6% of Earth’s, and is composed of 95.32% CO2, 2.7% N2 and 1.6% argon by volume. Mars’ dramatic transition is tied to the loss of its atmosphere, so the big question is, how did Mars lose its atmosphere?

    One of the main differences between the Earth and Mars is the lack of a significant magnetic field and smaller surface gravity on Mars.

    Magnetic field in a geodynamo simulation, created by Hiroaki Matsui using Calypso code
    Magnetic field in a geodynamo simulation, created by Hiroaki Matsui using Calypso code

    A global magnetic field provides shielding from incoming charged particles and also prevents escape of outgoing ions.

    Mars is too small, has only half Earth’s diameter, 11% its mass and 38% its gravity thus making it easy for upper layers to escape into the vacuum of space.

    “All of these [factors] point to the loss of the Martian atmosphere in the earliest stages,”

    Jakosky said. In 2015, Jakosky and his colleagues suggest that the solar wind was a major driver of Martian atmosphere loss:

    “That stripping would then have proceeded very quickly, “within a few hundred million years after the shutoff of the magnetic field,”

    Jakosky said.

    2
    An artist’s rendition depicts a solar storm hitting Mars and stripping ions from the upper atmosphere. (Courtesy NASA GSFC)

    “Our observations show unambiguously that a planet with no global magnetic field can [be] exposed to the full force of the solar wind and solar storms,

    he said.

    Mars’ atmosphere took a beating.”

    Nearby Supernovae contribute to Mars atmosphere loss?

    In a new study*, uploaded on arxiv servers on May 3, astronomer Dimitra Atri suggest that in addition to solar storms and radiations, it is likely that Mars atmosphere has been exposed to radiation bursts from high-energy astrophysical sources which become highly probable on timescales of billion years and beyond.

    The idea that nearby supernovae can inject energy and damage planetary atmospheres was given by Ruderman (1974). Recent reports based on the on measurements of 60Fe deposition on the ocean floor provide evidence of a 2.2 million years old supernova located at a distance between 20-430 light years away from Mars.

    Other studies also report the possibility of 16 events in the past 13 million years within 320 light years in the Local Bubble.

    So, supernovae explosion are not rare, scientists calculated this frequency of such nearby explosions, with at least one event occurring every 2-4 million year. On timescales of billion of years, such events become important.

    “On longer timescales of billion years, one can assume that a large number of such events would have deposited energy in the Martian atmosphere.”

    Atri remarks.

    Atri team’ calculations suggest a significant probability of a Galactic GRB beaming towards the Red Planet in the past 1 billion years. Atri’ models appears to be the most effective in Mars atmosphere depletion due to long duration of the event.

    “It’s incredibly satisfying to get to this point and realize that we really are answering the questions we set out to when we started the mission,

    Jakosky said.

    We’re beginning to understand what drives climate change on Mars, and to try to generalize to planets more generally.”

    *Science paper:
    Did high energy astrophysical sources contribute to Martian atmospheric loss?

    See the full article here .

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