Astronomers Find First Earth-like Planet in Habitable Zone

     Related Videos
Astronomers Confirm Star Survives Supernova Blast - DEM L241
First pictures of a black hole - gravity telescopes Astronomy Astronomers antimatter
Astronomers and NASA Detect Mysterious Signal coming from Deep Space

     More from this user

     Related Groups


     More on Sciencestage.com


 
  • Video url:                           Embed code: 

  • physicians  status
    (75%) (4 Votes)
    Views: (21501)   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
  • New Hubble Telescope images show star exploding 4 times
    New Hubble Telescope images show star exploding 4 times Astronomers observed the exciting and rare cosmic spectacle of a star exploding four times at different points across the galaxy, thanks to images produced by the Hubble Telescope. RT's Anya.... From: Bannet Bantey Views: 0 0 ratings Time: 02:25 More in News & Politics
  • Astronomers Discover Ring system 200 times bigger than Saturn
    Astronomers Discover Ring system 200 times bigger than Saturn Please Like And Subscribed to my channel for daily updates :) From: News Hitz Views: 0 0 ratings Time: 02:14 More in News & Politics
  • Astronomers Find Dark Matter Even Darker than Previously Thought
    Astronomers Find Dark Matter Even Darker than Previously Thought Astronomers using observations from NASA's Hubble Space Telescope and +NASA's Chandra X-ray Observatory have found that dark matter interacts with itself even less than previously thought... From: Hubble Space Telescope Views: 2903 103 ratings Time: 58:36 More in Education
  • #astroHangout #4: Weekly Live Chat with Adler Astronomers
    #astroHangout #4: Weekly Live Chat with Adler Astronomers Weekly live chat with Adler Planetarium astronomers, exploring the weird, beautiful, and intriguing moments in astronomy and space news this week. Drs. Laura Trouille (@windycityastro),... From: Adler Planetarium Views: 0 0 ratings Time: 00:00 More in Entertainment
  • #astroHangout #3: Weekly Live Chat with Adler Astronomers
    #astroHangout #3: Weekly Live Chat with Adler Astronomers Weekly live chat with Adler Planetarium astronomers, exploring the weird, beautiful, and intriguing moments in astronomy and space news this week. Drs. Laura Trouille (@windycityastro),... From: Adler Planetarium Views: 1 0 ratings Time: 33:11 More in Entertainment
  • How To Pronounce astronomers
    How To Pronounce astronomers How To Pronounce astronomers. From: OnychaHazel Views: 0 0 ratings Time: 00:04 More in Education
  • [BBC Space Documentary 2014 HD] Finding the new Earth - New Science Full Length
    [BBC Space Documentary 2014 HD] Finding the new Earth - New Science Full Length [BBC Space Documentary 2014 HD] Finding the new Earth - New Science Full Length Join astronomers in a race to find a planet that can sustain life. Amid all the space in the universe, is there... From: Kriste Custi Views: 0 0 ratings Time: 04:16:56 More in People & Blogs
  • Pioneers of Science Astronomers and Physicists, inc Newton, Galilei, etc , Audiobook
    Pioneers of Science Astronomers and Physicists, inc Newton, Galilei, etc , Audiobook From: karam07 Views: 0 0 ratings Time: 11:12:03 More in People & Blogs
  • Haleakala Amateur Astronomers facility
    Haleakala Amateur Astronomers facility From: Alex Dzierba Views: 1 1 ratings Time: 01:14 More in People & Blogs
  • [BBC Space Documentary 2014 HD] Finding the new Earth - New Science Full Length
    [BBC Space Documentary 2014 HD] Finding the new Earth - New Science Full Length [BBC Space Documentary 2014 HD] Finding the new Earth - New Science Full Length Join astronomers in a race to find a planet that can sustain life. Amid all the space in the universe, is there... From: Hugo Goines Views: 0 0 ratings Time: 03:01:03 More in People & Blogs
  • Astronomers In China (Extended Version)
    Astronomers In China (Extended Version) VA - From Russia With Italo Disco Vol II (2012) From: Mix Channel Music Views: 0 0 ratings Time: 07:02 More in Music
  • Astronomers find an Ancient Earth! 1 pixel science is amazing!
    Astronomers find an Ancient Earth! 1 pixel science is amazing! The Kepler-444 star system is ancient and has 5 Earth like planets so come along with me and the blue beetle on this most excellent adventure where I ask how much can you REALLY know from 1... From: thornews Views: 3784 185 ratings Time: 12:13 More in Science & Technology
  • #AstroHangout #2: Adler Astronomers & Friends on Exoplanets & Atmospheres
    #AstroHangout #2: Adler Astronomers & Friends on Exoplanets & Atmospheres Weekly live chat with Adler Planetarium astronomers. This week's chat will be all about exoplanets (planets around other stars) and exoplanet & stellar atmospheres. Drs. Laura Trouille (@windycity... From: Adler Planetarium Views: 29 0 ratings Time: 30:41 More in Entertainment
  • Nibiru and Dozens of Dead Astronomers/ A Coincidence?
    Nibiru and Dozens of Dead Astronomers/ A Coincidence? Music By Globus Have made no accusations or asserted any motives. Just the facts. None of these men died from the number one killer of men over 60. I don't know what it means. But it certainly...... From: Tomoyo yamamoto Views: 1 0 ratings Time: 13:17 More in Film & Animation
  • Pioneers of Science Astronomers and Physicists, inc Newton, Galilei, etc , Audiobook
    Pioneers of Science Astronomers and Physicists, inc Newton, Galilei, etc , Audiobook From: milton 17HHhii03 Views: 0 0 ratings Time: 11:12:03 More in People & Blogs
  • Seeing Stars Amateur Astronomers Aim Thousands of Eyes at the Universe YouTube
    Seeing Stars Amateur Astronomers Aim Thousands of Eyes at the Universe YouTube From: Tự Học Tiếng Anh Views: 0 0 ratings Time: 03:36 More in People & Blogs
  • Astronomers Tracking Nibiru & Leaking its secrets!
    Astronomers Tracking Nibiru & Leaking its secrets! Astronomers Tracking Nibiru & Leaking its secrets! Astronomers Tracking Nibiru & Leaking its secrets! Subscribe: https://www.youtube.com/channel/UCUb6CP8V3x6TtaAwLV8U9Yg The new planet, ... From: SCIENCE TV Views: 114 2 ratings Time: 15:12 More in People & Blogs
  • Contact In The Desert - Alejandro T. Rojas - Astronomers, UFOs, ET's, Religion, Roswell In
    Contact In The Desert - Alejandro T. Rojas - Astronomers, UFOs, ET's, Religion, Roswell In Robert Perala Interviews; Erich von Daniken, Mike Bara, Daniel Sheehan, Nick Redfern and Travis Walton PLAYLIST (Click Here) 2014 Contact In The Desert Conference. 2014 Contact In The... From: unarb inaeumn Views: 4 0 ratings Time: 02:39:04 More in Film & Animation
  • #astroHangout #1 with Adler Planetarium Astronomers
    #astroHangout #1 with Adler Planetarium Astronomers Weekly live chat with Adler Planetarium astronomers, recapping the week in astronomy and space news. Drs. Laura Trouille (@windycityastro), Lucianne Walkowicz (@shaka_lulu), Alissa Bans, and... From: Adler Planetarium Views: 29 0 ratings Time: 24:26 More in Entertainment
  • How can astronomers “observe the past”?
    How can astronomers “observe the past”? From our Series: Science Discovers the Universe Had a Beginning. From: John Ankerberg Views: 169 4 ratings Time: 04:19 More in Nonprofits & Activism
  • Potentially Hazardous Asteroid Surprises Astronomers
    Potentially Hazardous Asteroid Surprises Astronomers First Pictures From WISE Spacecraft - The NASA/JPL Wide-field Infrared Survey Explorer. --- Please SUBSCRIBE to Science... NASA's Near-Earth Object Wide-field Survey Explorer (NEOWISE)... From: documentaryy economy Views: 10 0 ratings Time: 04:31 More in Autos & Vehicles
  • Astronomers Discover Ancient Solar System with 5 Earth-Like Planets.mp4
    Astronomers Discover Ancient Solar System with 5 Earth-Like Planets.mp4 From: dahboo777 Views: 3 0 ratings Time: 01:59 More in News & Politics
  • Synopsis | From Hubble To Hubble: Astronomers And Outer Space
    Synopsis | From Hubble To Hubble: Astronomers And Outer Space THE SYNOPSIS OF YOUR FAVORITE BOOK =--- Where to buy this book? ISBN: 9780743905640 Book Synopsis of From Hubble to Hubble: Astronomers and Outer Space by Readers Science If... From: Maminha Books Views: 0 0 ratings Time: 00:39 More in Education
  • Are Alien Astronomers Key To Finding Extra-Terrestrial Life?
    Are Alien Astronomers Key To Finding Extra-Terrestrial Life? Alien Astronomers (2012): Astronomers at the Keck telescope have an exciting new method in the hunt for ET Subscribe to Journeyman for daily uploads: http://www.youtube.com/journeymanpictures... From: Journeyman Pictures Views: 6498 135 ratings Time: 08:00 More in News & Politics
  • Can astronomers see evidence of design by looking at the universe
    Can astronomers see evidence of design by looking at the universe Can astronomers see evidence of design when they look at the beginning of the universe? From our Series: Science Discovers the Universe Had a Beginning. From: John Ankerberg Views: 339 15 ratings Time: 04:00 More in Nonprofits & Activism

  •      Related Answers Results



























       

      Powered free by PHPmotion