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Thread: Exoplanets

  1. #1 Exoplanets 
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    Exoplanets are on the cutting edge of astronomy. These are planets circling stars other than our sun. 853 have been confirmed as of December 1, 2012. There are no doubt billions in the Milky Way galaxy.

    51 Pegasi was the first main-sequence star around which an exoplanet was discovered. That was in 1995.

    Geoff Marcy and his team at the University of California Berkeley are at the forefront of exoplanet research.

    I wonder why everything is a "team" now. What happened to giants like Copernicus and Hubble?

    So far, it has been mostly Super-Earths and large gas planets called Hot Jupiters. But Kepler has found Earth-size planets, and some may be in their star's habitable zone, where it is not too hot and not too cold and liquid water may exist.

    Most exoplanets have elongated, eccentric orbits. Many orbit very close to their stars.

    Scientists are looking for an Earth twin, a rocky planet taking about one Earth year to complete its orbit.

    Scientists at the European Southern Observatory in Chile claim to have found Earth-like planets in Gliese 581 c and d. They lie in or near their star's habitable zone. Gliese 581 in Libra is 20 light years away.

    NASA's Kepler Space Telescope uses the transit method. It measures a star's dimming as planets cross in front of it.

    Kepler 22-b may be an Earth-like planet in terms of size and temperature. It is in the Goldilocks zone at 600 light years.

    Alpha Centauri is the closest star to us at 4.4 light years. It is a triple star, and an exoplanet is orbiting a Centauri B. It is similar to Earth in mass but too near its parent star for life. The planet was spotted at the ESO using the radial velocity method. The star's wobble caused by the planet's gravitational tug was detected. It is analogous to a large man dancing with a small woman. He may whirl her around, but she will also have an effect on him. It makes sense that stars near our sun would be the best candidates for having Earth-like planets.

    It is clear that our solar system is not unique, and the search is already on for extragalactic planets. These would be planets in galaxies such as M31.



    Extraterrestrial life -
    Astronomers and other scientists are in a desperate search for life beyond our own planet. The question "Are we alone?" is more relevant now than at any time in history. Curiosity is looking for signs of life on Mars. The field of astrobiology is opening even though nothing has been found.

    If organic molecules were in the protoplanetary disk surrounding the sun, then life may exist somewhere in the solar system. Jupiter's moon Europa may be suitable for life as well as Saturn's moons Titan and Enceladus. There may be oceans under ice.

    It is thought that liquid water one flowed on Mars and may still exist beneath its surface. Mars may have been warmer in the past. No life has been confirmed.

    NASA scientists want to find extraterrestrial life so bad that they tend to jump to conclusions. I would guess in some cases they even lie.

    SETI (Search for Extraterrestrial Intelligence) uses radio telescopes like Arecibo in Puerto Rico. SETI has failed to detect intelligent radio signals in more than five decades of trying.

    Even if there are advanced ET civilizations, they may not be transmitting in our direction. And if they are, we may not be able to interpret their signals. Also, because of the distances involved, any radio activity would come from the remote past.

    Six elements are basic to life on earth: carbon, hydrogen, nitrogen, oxygen, phosphorus and sulfur. It is assumed that these elements would be at the basis of alien life. Scientists also assume that alien life would be DNA based. Water provides a solvent in which biochemistry takes place.

    Maybe life elsewhere in the Milky Way or in other galaxies would not be based on carbon and DNA. DNA is the hereditary material in cells known for its double helix.

    Microbes were found below ice in Antarctica’s Lake Vida. The discovery of life in this extremely cold habitat makes us ponder the potential for extraterrestrial life on moons like Europa.

    Science fiction depicts aliens with humanoid or reptilian features. Aliens are described as green or grey and having large heads.

    The term UFO was coined in 1947 after the Roswell incident and the alleged sighting of flying saucers by Kenneth Arnold. Conspiracy theories abound. Ufologists claim that the government is involved in a cover-up. They want "disclosure" while citing the secrecy of Nevada's Area 51.

    The White House Office of Science and Technology Policy posted this on the White House website:

    “The U.S. government has no evidence that life exists outside our planet, or that an extraterrestrial presence has contacted or engaged any member of the human race. In addition, there is no credible information to suggest that any evidence is being hidden from the public eye.”

    The ancient aliens of Giorgio Tsoukalos and Erich von Daniken are a mix of space age mythology, folklore and science fiction.


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  3. #2 NASA employees 
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    One thing i would like to talk here about what NASA Scientists say about finding life outside from earth it’s a truth that they are not success yet, It is sure that NASA employees tells things in hyper mood always over excited but these guys are not success in this mission.


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  4. #3  
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    So far, no evidence has been confirmed that there is any life outside of Earth.
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    yep that is true, though there's still the possibility that maybe on far galaxies living things also exists.
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  6. #5  
    Forum Radioactive Isotope cosmictraveler's Avatar
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    The Drake equation states that:
    where:

    N = the number of civilizations in our galaxy with which communication might be possible (i.e. which are on our current past light cone);and
    R* = the average rate of star formation per year in our galaxyfp = the fraction of those stars that have planetsne = the average number of planets that can potentially support life per star that has planetsf = the fraction of the above that actually go on to develop life at some pointfi = the fraction of the above that actually go on to develop intelligent lifefc = the fraction of civilizations that develop a technology that releases detectable signs of their existence into spaceL = the length of time for which such civilizations release detectable signals into space[5][edit] R factor

    One can question why the number of civilizations should be proportional to the star formation rate, though this makes technical sense. (The product of all the factors except L tells how many new communicating civilizations are born each year. Then you multiply by the lifetime to get the expected number. For example, if an average of 0.01 new civilizations are born each year, and they each last 500 years on the average, then on the average 5 will exist at any time.)

    The original Drake Equation can be extended to a more realistic model, where the equation uses not the number of stars that are forming now, but those that were forming several billion years ago. The alternate formulation, in terms of the number of stars in the galaxy, is easier to explain and understand, but implicitly assumes the star formation rate is constant over the life of the galaxy.


    http://www.google.com/url?sa=t&rct=j...55325884,d.eWU
    Last edited by cosmictraveler; December 19th, 2012 at 10:25 AM.
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  7. #6  
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    Quote Originally Posted by Jim Colyer View Post
    Exoplanets are on the cutting edge of astronomy. These are planets circling stars other than our sun. 853 have been confirmed as of December 1, 2012. There are no doubt billions in the Milky Way galaxy.

    51 Pegasi was the first main-sequence star around which an exoplanet was discovered. That was in 1995.

    Geoff Marcy and his team at the University of California Berkeley are at the forefront of exoplanet research.

    I wonder why everything is a "team" now. What happened to giants like Copernicus and Hubble? .
    The case is the same everywhere so its not random.ONE explanation is a "Babel tower effect": science is no longer ONE culture with ONE language, specialists from different cummunities no longer synchronize easily.The effect is hardly noticeable through other damages, since more people than ever become scientists.
    Quote Originally Posted by Jim Colyer View Post
    So far, it has been mostly Super-Earths and large gas planets called Hot Jupiters. But Kepler has found Earth-size planets, and some may be in their star's habitable zone, where it is not too hot and not too cold and liquid water may exist.

    Most exoplanets have elongated, eccentric orbits. Many orbit very close to their stars.

    Scientists are looking for an Earth twin, a rocky planet taking about one Earth year to complete its orbit.

    Scientists at the European Southern Observatory in Chile claim to have found Earth-like planets in Gliese 581 c and d. They lie in or near their star's habitable zone. Gliese 581 in Libra is 20 light years away.

    NASA's Kepler Space Telescope uses the transit method. It measures a star's dimming as planets cross in front of it.

    Kepler 22-b may be an Earth-like planet in terms of size and temperature. It is in the Goldilocks zone at 600 light years.

    Alpha Centauri is the closest star to us at 4.4 light years. It is a triple star, and an exoplanet is orbiting a Centauri B. It is similar to Earth in mass but too near its parent star for life. .
    I think a more careful wordering should be used here...theres extremophiles...theres life deep down in the ground of earth. And the planet need not have been in the same orbit all the time.
    .
    Quote Originally Posted by Jim Colyer View Post
    The planet was spotted at the ESO using the radial velocity method. The star's wobble caused by the planet's gravitational tug was detected. It is analogous to a large man dancing with a small woman. He may whirl her around, but she will also have an effect on him. It makes sense that stars near our sun would be the best candidates for having Earth-like planets. .
    Why? Dont you mean that they are more easily observed?.
    Quote Originally Posted by Jim Colyer View Post
    It is clear that our solar system is not unique, and the search is already on for extragalactic planets. These would be planets in galaxies such as M31. .
    Surprising.
    Quote Originally Posted by Jim Colyer View Post
    Extraterrestrial life -
    Astronomers and other scientists are in a desperate search for life beyond our own planet. The question "Are we alone?" is more relevant now than at any time in history. Curiosity is looking for signs of life on Mars. The field of astrobiology is opening even though nothing has been found.
    No surprise there. We have been taught to believe we are unique! The elementary resoning should go: Life is no accident...no mysterious unique happening only in our solar system. The bigger the universe is the more independent life there should be in it. From the beginning we should have asked other more relevant questions.

    Quote Originally Posted by Jim Colyer View Post

    If organic molecules were in the protoplanetary disk surrounding the sun, then life may exist somewhere in the solar system.
    Indeed! And have stellar clouds empty of organics been found? If life at different places in the system can be shown to be related then life was probably formed before the planets were formed. There must have been "spots" where water was neither ice nor vapour.
    Quote Originally Posted by Jim Colyer View Post

    have Jupiter's moon Europa may be suitable for life as well as Saturn's moons Titan and Enceladus. There may be oceans under ice.

    It is thought that liquid water one flowed on Mars and may still exist beneath its surface. Mars may have been warmer in the past. No life has been confirmed.

    NASA scientists want to find extraterrestrial life so bad that they tend to jump to conclusions. I would guess in some cases they even lie.
    Who doesnt?
    Quote Originally Posted by Jim Colyer View Post
    SETI (Search for Extraterrestrial Intelligence) uses radio telescopes like Arecibo in Puerto Rico. SETI has failed to detect intelligent radio signals in more than five decades of trying.

    Even if there are advanced ET civilizations,.
    How come you doubt? The only reasonable question I see is: How far away are they?
    There is a Zillions to one possibility that we are the ONLY civilisation in the universe.
    Quote Originally Posted by Jim Colyer View Post
    they may not be transmitting in our direction. And if they are, we may not be able to interpret their signals. Also, because of the distances involved, any radio activity would come from the remote past.

    Six elements are basic to life on earth: carbon, hydrogen, nitrogen, oxygen, phosphorus and sulfur. It is assumed that these elements would be at the basis of alien life. Scientists also assume that alien life would be DNA based. Water provides a solvent in which biochemistry takes place.
    To this I add my "speculation" that there in every solar system (except the earliest ones) there are several large volumes, existing for a long time, where conditions are suitable for life to appear.

    Quote Originally Posted by Jim Colyer View Post

    Maybe life elsewhere in the Milky Way or in other galaxies would not be based on carbon and DNA. DNA is the hereditary material in cells known for its double helix.
    This idea was proposed in order to raise the probability that we are not alone... Since that probability is not in need of rising higher I suggest we skip unnecessary speculations... No life on neutron stars and so on Ok?
    Quote Originally Posted by Jim Colyer View Post
    Microbes were found below ice in Antarctica’s Lake Vida. The discovery of life in this extremely cold habitat makes us ponder the potential for extraterrestrial life on moons like Europa.

    Science fiction depicts aliens with humanoid or reptilian features. Aliens are described as green or grey and having large heads.
    And ghosts are white...
    Quote Originally Posted by Jim Colyer View Post

    The term UFO was coined in 1947 after the Roswell incident and the alleged sighting of flying saucers by Kenneth Arnold. Conspiracy theories abound. Ufologists claim that the government is involved in a cover-up. They want "disclosure" while citing the secrecy of Nevada's Area 51.

    The White House Office of Science and Technology Policy posted this on the White House website:

    “The U.S. government has no evidence that life exists outside our planet, or that an extraterrestrial presence has contacted or engaged any member of the human race. In addition, there is no credible information to suggest that any evidence is being hidden from the public eye.”

    The ancient aliens of Giorgio Tsoukalos and Erich von Daniken are a mix of space age mythology, folklore and science fiction.
    This going through Myths you should have skipped. Lets face reality instead: Our picture of the world is a mixture of the religious outlook and science. Science had to fight for each incremental step. The religious reasoning is so deeply tattoed in the cultural mind that its still today one of the strongest cultural forces on earth...Just look at your own formulations!

    The proper thing to do is to start from the diametrically opposite place in the spectrum of possibilities!

    (1) Life is a fundamental consequence of the universe.
    instead of (Life is a wonderful and improbable gift from god)
    (2) There is life in all stellar systems.
    instead of (there is only life on earth)

    (3)Im not gonna go through the whole list... WHY DONT YOU DO IT BY YOURSELF?

    I will instead ask a question: Science is unaffected you say:
    So where is the the Theory of the Consequenses Life will have on the Universe?
    Last edited by sigurdV; December 17th, 2012 at 03:22 PM.
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  8. #7  
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    I like to believe that where ever life can exist in the universe, it either does or it will.

    First, if life on Earth is the example we have to work with, it's a good bet that carbon based life will be the most common form of life through out the universe. Yes I'm leaving open the possibility of other forms of life. For one thing we are almost on the verge of creating machine life and who's to say that hasn't happened else where in the universe.

    But I will point out that machine life might be the natural order of things where ever carbon based life becomes technological.

    What advantages would machine life have over biological life. First and foremost, it would be able to evolve much faster than biological life and it could create and adapt itself to a greater range of extremes and therefore live in a lot of places humans can't or just plain wouldn't want to.

    Can humans an intelligent self aware machines co-exist? I'd like to think so, but it's a bit early to tell.
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