Astronomers Find First Earth-like Planet in Habitable Zone


     Related Videos
First pictures of a black hole - gravity telescopes Astronomy Astronomers antimatter

     More from this user

     Related Groups


     More on Sciencestage.com


 
  • Video url:                           Embed code: 

  • physicians  status
    (75%) (4 Votes)
    Views: (14946)   Date: (02-04-09)   Time: (00:04:37)
  • Description: Astronomers have discovered the most Earth-like planet outside our Solar System to date, an exoplanet with a radius only 50% larger than the Earth and capable of having liquid water. Using the ESO 3.6-m telescope, a team of Swiss, French and Portuguese scientists discovered a super-Earth about 5 times the mass of the Earth that orbits a red dwarf, already known to harbour a Neptune-mass planet. The astronomers have also strong evidence for the presence of a third planet with a mass about 8 Earth masses.

    Extrasolar planet:

    An extrasolar planet, or exoplanet, is a planet beyond the Solar System, orbiting a star other than the Sun. As of March 2009, 344 exoplanets are listed in the Extrasolar Planets Encyclopaedia. The vast majority have been detected through radial velocity observations and other indirect methods rather than actual imaging. Most announced exoplanets are massive gas giant planets thought to resemble Jupiter, but this is a selection effect due to limitations in detection technology. Projections based on recent detections of much smaller worlds suggest that lightweight, rocky planets will eventually be found to outnumber extrasolar gas giants.

    Extrasolar planets became a subject of scientific investigation in the mid-19th century. Many astronomers supposed that such planets existed, but they had no way of knowing how common they were or how similar they might be to the planets of the Solar System. The first confirmed radial velocity detection was made in 1995, revealing a gas giant planet in a four-day orbit around the nearby G-type star 51 Pegasi. The frequency of detections has tended to increase on an annual basis since then. It is estimated that at least 10% of sun-like stars have planets, and the true proportion may be much higher. The discovery of extrasolar planets sharpens the question of whether some might support extraterrestrial life.

    Currently Gliese 581 d, the third planet of the red dwarf star Gliese 581 (approximately 20 light years from Earth), appears to be the best example yet discovered of a possible terrestrial exoplanet that orbits close to the habitable zone surrounding its star. Although Gliese 581 d appears to reside outside the so-called "Goldilocks Zone", a potential greenhouse effect might raise the planet's surface temperature high enough to support liquid water. Retracted discoveries

    Unconfirmed until 1988, extrasolar planets have long been assumed as plausible, and speculation on planets circling around the fixed stars dates to at least the early 18th century, with Isaac Newton's "General Scholium" (1713), which has "And if the fixed Stars are the centers of other like systems, these, being form'd by the like wise counsel, must be all subject to the dominion of One" (trans. Motte 1729). Our solar system compared with the system of 55 Cancri

    Claims about detection of exoplanets have been made from the 19th century. Some of the earliest involve the binary star 70 Ophiuchi. In 1855 Capt. W. S. Jacob at the East India Company's Madras Observatory reported that orbital anomalies made it "highly probable" that there was a "planetary body" in this system. In the 1890s, Thomas J. J. See of the University of Chicago and the United States Naval Observatory stated that the orbital anomalies proved the existence of a dark body in the 70 Ophiuchi system with a 36-year period around one of the stars. However, Forest Ray Moulton soon published a paper proving that a three-body system with those orbital parameters would be highly unstable. During the 1950s and 1960s, Peter van de Kamp of Swarthmore College made another prominent series of detection claims, this time for planets orbiting Barnard's Star. Astronomers now generally regard all the early reports of detection as erroneous.

    In 1991, Andrew Lyne, M. Bailes and S.L. Shemar claimed to have discovered a pulsar planet in orbit around PSR 1829-10, using pulsar timing variations. The claim briefly received intense attention, but Lyne and his team soon retracted it.

    Confirmed discoveries Our inner solar system superimposed behind the orbits of the planets HD 179949 b, HD 164427 b, Epsilon Reticuli Ab, and Mu Arae b (all parent stars are in the center)

    The first published discovery to have received subsequent confirmation was made in 1988 by the Canadian astronomers Bruce Campbell, G. A. H. Walker, and S. Yang. Their radial-velocity observations suggested that a planet orbited the star Gamma Cephei. They remained cautious about claiming a true planetary detection, and widespread skepticism persisted in the astronomical community for several years about this and other similar observations. It was mainly because the observations were at the very limits of instrumental capabilities at the time. Another source of confusion was that some of the possible planets might instead have been brown dwarfs, objects that are intermediate in mass between planets and stars.

    The following year, additional observations were published that supported the reality of the planet orbiting Gamma Cephei, though subsequent work in 1992 raised serious doubts. Finally, in 2003, improved techniques allowed the planet's existence to be confirmed.

    In early 1992, radio astronomers Aleksander Wolszczan and Dale Frail announced the discovery of planets around another pulsar, PSR 1257+12. This discovery was quickly confirmed, and is generally considered to be the first definitive detection of exoplanets. These pulsar planets are believed to have formed from the unusual remnants of the supernova that produced the pulsar, in a second round of planet formation, or else to be the remaining rocky cores of gas giants that survived the supernova and then spiralled into their current orbits.

    On October 6, 1995, Michel Mayor and Didier Queloz of the University of Geneva announced the first definitive detection of an exoplanet orbiting an ordinary main-sequence star (51 Pegasi). This discovery was made at the Observatoire de Haute-Provence and ushered in the modern era of exoplanetary discovery. Technological advances, most notably in high-resolution spectroscopy, led to the detection of many new exoplanets at a rapid rate. These advances allowed astronomers to detect exoplanets indirectly by measuring their gravitational influence on the motion of their parent stars. Several extrasolar planets were eventually also detected by observing the variation in a star's apparent luminosity as a planet passed in front of it.

    To date, 344 exoplanets have been found, including a few that were confirmations of controversial claims from the late 1980s. The first system to have more than one planet detected was Ï… And. Twenty such multiple-planet systems are now known. Among the known exoplanets are four pulsar planets orbiting two separate pulsars. Infrared observations of circumstellar dust disks also suggest the existence of millions of comets in several extrasolar systems.

    Detection methods Main article: Methods of detecting extrasolar planets

    Planets are extremely faint light sources compared to their parent stars. At visible wavelengths, they usually have less than a millionth of their parent star's brightness. In addition to the intrinsic difficulty of detecting such a faint light source, the parent star causes a glare that washes it out.

    For those reasons, current telescopes can only directly image exoplanets under exceptional circumstances. Specifically, it may be possible when the planet is especially large (considerably larger than Jupiter), widely separated from its parent star, and hot so that it emits intense infrared radiation.

    The vast majority of known extrasolar planets have been discovered through indirect methods: Diagram showing how an exoplanet orbiting a larger star could produce changes in position and velocity of the star as they orbit their common center of mass.

    * Astrometry: Astrometry consists of precisely measuring a star's position in the sky and observing the ways in which that position changes over time. If the star has a planet, then the gravitational influence of the planet will cause the star itself to move in a tiny circular or elliptical orbit about their common center of mass (see animation on the right).

    * Radial velocity or Doppler method: Variations in the speed with which the star moves towards or away from Earth — that is, variations in the radial velocity of the star with respect to Earth — can be deduced from the displacement in the parent star's spectral lines due to the Doppler effect. This has been by far the most productive technique used.

    * Pulsar timing: A pulsar (the small, ultradense remnant of a star that has exploded as a supernova) emits radio waves extremely regularly as it rotates. Slight anomalies in the timing of its observed radio pulses can be used to track changes in the pulsar's motion caused by the presence of planets.

    * Transit method: If a planet crosses (or transits) in front of its parent star's disk, then the observed brightness of the star drops by a small amount. The amount by which the star dims depends on its size and on the size of the planet.

    * Gravitational microlensing: Microlensing occurs when the gravitational field of a star acts like a lens, magnifying the light of a distant background star. Possible planets orbiting the foreground star can cause detectable anomalies in the lensing event light curve.

    * Circumstellar disks: Disks of space dust surround many stars, and this dust can be detected because it absorbs ordinary starlight and re-emits it as infrared radiation. Features in dust disks may suggest the presence of planets.

    * Eclipsing binary: In an eclipsing double star system, the planet can be detected by finding variability in minima as it goes back and forth. It is the most reliable method for detecting planets in binary star systems.

    * Orbital phase: Like the phase of the Moon and Venus, extrasolar planets also have phases. Orbital phases depends on inclination of the orbit. By studying orbital phases scientists can calculate particle sizes in the atmospheres of planets.

    * Polarimetry: Stellar light becomes polarized when it interacts with atmospheric molecules, which could be detected with a polarimeter. So far, one planet has been studied by this method.

    Not counting a few exceptions, all known extrasolar planet candidates have been found using ground-based telescopes. However, many of the methods can yield better results if the observing telescope is located above the restless atmosphere. COROT (launched in December 2006) and Kepler, (launched in March 2009) are the only active space mission dedicated to extrasolar planet search. Hubble Space Telescope has also found or confirmed a few planets. There are many planned or proposed space missions such as New Worlds Mission, Darwin, Space Interferometry Mission, Terrestrial Planet Finder, and PEGASE.

    SOURCE: WIKIPEDIA (http://en.wikipedia.org/wiki/Extrasolar_planet)

     Related Documents

     Related Wikipedia Results

     Related Pubmed Results

     Related Nature.com Results

     Related on Youtube Results
  • Southern Oregon Astronomers Fly With NASA on SOFIA Infrared Telescope Aircraft Apr 22nd, 2014
    Southern Oregon Astronomers Fly With NASA on SOFIA Infrared Telescope Aircraft Apr 22nd, 2014 From: ZP ZAP Views: 0 0 ratings Time: 02:01 More in Science & Technology
  • Southern Oregon Astronomers Fly With NASA - Apr 22nd, 2014
    Southern Oregon Astronomers Fly With NASA - Apr 22nd, 2014 For more, visit http://kobi5.com. From: KOBI Tee-Vee Views: 0 0 ratings Time: 02:00 More in News & Politics
  • Astronomers Find the Most Distant Galaxy Yet
    Astronomers Find the Most Distant Galaxy Yet Astronomers working together from several international institutions have discovered the most distant galaxy ever, using data from the Hubble Space Telescope... From: ProBig Views: 0 0 ratings Time: 01:07 More in News & Politics
  • FIFA 14 iPhone/iPad - Astronomers vs. Manchester Utd
    FIFA 14 iPhone/iPad - Astronomers vs. Manchester Utd http://smarturl.it/FIFA14_Ytube_WW WE ARE FIFA 14! The most popular sports franchise is back in your hands with all new ways to play on mobile. And this year... From: Astroboy_900 Views: 0 0 ratings Time: 00:09 More in Gaming
  • Planet Found Covered in Lava, Similar in Size to Earth
    Planet Found Covered in Lava, Similar in Size to Earth Astronomers have found an exoplanet 400 light years from Earth that has a similar density to our own planet, but is orbiting a hundredth of the distance from... From: ProBig Views: 0 0 ratings Time: 01:07 More in News & Politics
  • Newly Found Asteroid To Fly Between Earth and Moon | Orbit Animation
    Newly Found Asteroid To Fly Between Earth and Moon | Orbit Animation Newly Found Asteroid To Fly Between Earth and Moon | Orbit Animation hd The space rock, named 2013 RZ53, was discovered on September 13th, 2013, by astronome... From: Thomas C. Preuss Views: 0 0 ratings Time: 04:35 More in News & Politics
  • How to pronounce astronomers
    How to pronounce astronomers Learn how to say astronomers correctly with our pronounciation tutorials. From: Bret Liang Views: 0 0 ratings Time: 00:13 More in Entertainment
  • 'Most Earth like planet yet' may be habitable, NASA scientists say
    'Most Earth like planet yet' may be habitable, NASA scientists say Scientists have discovered there may be life on an Earth-like planet in a far off solar system. It's the first time such a find has been made of a planet tha... From: Shasti Verdicia Views: 0 0 ratings Time: 00:51 More in News & Politics
  • Asteroid Found with Rings! First-of-Its-Kind Discovery Stuns Astronomers
    Asteroid Found with Rings! First-of-Its-Kind Discovery Stuns Astronomers A team of astronomers is puzzling over an unprecedented discovery--the first ever observed asteroid with its own ring system. The asteroid Chariklo, which is... From: BARBIESOWW Views: 0 0 ratings Time: 07:56 More in Film & Animation
  • Astronomers Discover Weird Six-Tailed Asteroid
    Astronomers Discover Weird Six-Tailed Asteroid The Hubble telescope has caught a glimpse of a strange six-tailed asteroid spinning in space. The Hubble telescope has caught a glimpse of a strange six-tail... From: ProBig Views: 0 0 ratings Time: 01:07 More in News & Politics
  • Sun's Magnetic Poles Reverse
    Sun's Magnetic Poles Reverse The magnetic poles of the sun are getting ready to switch upside down, making the positive side negative and vice versa. The magnetic poles of the sun are ge... From: HugBig Views: 0 0 ratings Time: 01:08 More in News & Politics
  • Kepler-186f : First Earth-size Planet Discovered in the Habitable Zone of Another Star [HD
    Kepler-186f : First Earth-size Planet Discovered in the Habitable Zone of Another Star [HD April 17, 2014. Using NASA's Kepler Space Telescope, astronomers have discovered the first Earth-size planet orbiting a star in the habitable zone -- the . N... From: idris midis Views: 0 0 ratings Time: 00:55 More in Film & Animation
  • NASA finds most Earth like planet to date
    NASA finds most Earth like planet to date NASA's Kepler Space Telescope has found an Earth-sized planet within the habitable zone of the star it orbits, the space agency announced Thursday. The plane... From: powerviness Views: 0 0 ratings Time: 00:59 More in News & Politics
  • Kepler astronomers discover new rocky planet that may have liquid water
    Kepler astronomers discover new rocky planet that may have liquid water Kepler astronomers discover new rocky planet that may have liquid water. From: Kadin Lott Views: 0 0 ratings Time: 06:57 More in People & Blogs
  • FIFA 14 iPhone/iPad - Astronomers vs. Sogndal
    FIFA 14 iPhone/iPad - Astronomers vs. Sogndal http://smarturl.it/FIFA14_Ytube_WW WE ARE FIFA 14! The most popular sports franchise is back in your hands with all new ways to play on mobile. And this year... From: Astroboy_900 Views: 2 0 ratings Time: 00:07 More in Gaming
  • FIFA 14 iPhone/iPad - Astronomers vs. FC Lausanne
    FIFA 14 iPhone/iPad - Astronomers vs. FC Lausanne http://smarturl.it/FIFA14_Ytube_WW WE ARE FIFA 14! The most popular sports franchise is back in your hands with all new ways to play on mobile. And this year... From: Astroboy_900 Views: 0 0 ratings Time: 00:10 More in Gaming
  • Kepler astronomers discover new rocky planet that may have liquid water
    Kepler astronomers discover new rocky planet that may have liquid water Kepler astronomers discover new rocky planet that may have liquid water. From: Suraj Panchal Views: 0 0 ratings Time: 06:57 More in People & Blogs
  • Astronomers discover Earth-sized planet in habitable zone
    Astronomers discover Earth-sized planet in habitable zone Astronomers discover Earth-sized planet in habitable zone. From: Ganganam Aarya Views: 0 0 ratings Time: 03:20 More in People & Blogs
  • Astronomers Peer Into Supermassive Black Hole Jets | Video
    Astronomers Peer Into Supermassive Black Hole Jets | Video Using the Atacama Large Millimeter/submilimeter Array in Chile, astronomers probed the supermassive black holes that are at the center of most galaxies, prin... From: BackSpace Views: 0 0 ratings Time: 02:21 More in Science & Technology
  • Giant Planet Forming Solar System Discovered By Japanese Astronomers | Animation
    Giant Planet Forming Solar System Discovered By Japanese Astronomers | Animation Astronomers from the Osaka University and Ibaraki University have found evidence of dust particles colliding to form protoplanets around a young star named H... From: BackSpace Views: 0 0 ratings Time: 01:24 More in Science & Technology
  • Giant Planet Forming Solar System Discovered By Japanese Astronomers | Animation
    Giant Planet Forming Solar System Discovered By Japanese Astronomers | Animation Astronomers from the Osaka University and Ibaraki University have found evidence of dust particles colliding to form protoplanets around a young star named H... From: BackSpace Views: 0 0 ratings Time: 01:24 More in Science & Technology
  • Astronomers confirmed First Earth Size Planet in Habitable Zone Kepler 186 f
    Astronomers confirmed First Earth Size Planet in Habitable Zone Kepler 186 f LEGAL DISCLAIMER: Regarding Copyright Law Any video from our channel may or may not at any time contain in full or in part, a series or multiple series of de... From: lordfec6 Views: 22 0 ratings Time: 01:52 More in News & Politics
  • Astronomers detect Earth like planet
    Astronomers detect Earth like planet From: worldnews24/7 Views: 2 0 ratings Time: 01:02 More in News & Politics
  • NASA astronomers discuss Kepler-186f
    NASA astronomers discuss Kepler-186f Elisa Quintana and Thomas Barclay are both research scientists at the SETI Institute at NASA's Ames Research Center and the astronomers who discovered the pl... From: Kanim Kanin Views: 254 0 ratings Time: 01:34 More in News & Politics
  • Planet Similar to Earth Found by Astronomers to Be Hotter and Puffier
    Planet Similar to Earth Found by Astronomers to Be Hotter and Puffier An exoplanet that has a mass similar to Earth has been observed by astronomers using NASA's Kepler space telescope. An exoplanet that has a mass similar to E... From: ProBig Views: 0 0 ratings Time: 01:13 More in News & Politics

  •      Related Answers Results



























     

    Powered free by PHPmotion