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: (18892)   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
  • Finally Some Truth About Nibiru For Once
    Finally Some Truth About Nibiru For Once Finally Some Truth About Nibiru For Once Follow me on Astronomers reject the idea of Nibiru, and have made efforts to inform the public that there is no threat to Earth. They point out that... From: Alfonso Mills Views: 0 0 ratings Time: 02:22:46 More in Education
  • Astronomers Keeping an Eye on the Biggest Solar Flare in Nearly a Quarter Century #2| October 31
    Astronomers Keeping an Eye on the Biggest Solar Flare in Nearly a Quarter Century #2| October 31 While the flare poses no threat to Earth, it could cause radio wave blackouts. From abcNews While the flare poses no threat to Earth, it could cause radio wave blackouts. From: Hot News Of The World Views: 1 0 ratings Time: 00:34 More in People & Blogs
  • Astronomers Keeping an Eye on the Biggest Solar Flare in Nearly a Quarter Century #1| October 31
    Astronomers Keeping an Eye on the Biggest Solar Flare in Nearly a Quarter Century #1| October 31 While the flare poses no threat to Earth, it could cause radio wave blackouts. From abcNews While the flare poses no threat to Earth, it could cause radio wave blackouts. From: Hot News Of The World Views: 2 0 ratings Time: 00:37 More in People & Blogs
  • Astronomers Keeping an Eye on the Biggest Solar Flare in Nearly a Quarter Century
    Astronomers Keeping an Eye on the Biggest Solar Flare in Nearly a Quarter Century OSMANSA NEWS. From: DORUKSA NEWS 12 Views: 0 0 ratings Time: 01:36 More in News & Politics
  • Here I will teach you how to pronounce 'astronomers' with Zira.mp4
    Here I will teach you how to pronounce 'astronomers' with Zira.mp4 Here I will teach you how to pronounce 'astronomers' with Zira.mp4. From: Pronounce words Views: 0 0 ratings Time: 00:15 More in Entertainment
  • Astro Locator · App Preview
    Astro Locator · App Preview Astro Locator makes it simple for astronomers to get polar aligned both quickly and easily. It is of particular benefit to new astronomers who set up and break down each session, so is of... From: Progress Concepts Views: 1 0 ratings Time: 00:30 More in Science & Technology
  • Astro Locator · Astronomy Polaris polar alignment made quick & easy
    Astro Locator · Astronomy Polaris polar alignment made quick & easy Astro Locator makes it simple for astronomers to get polar aligned both quickly and easily. It is of particular benefit to new astronomers who set up and break down each session, so is of... From: Progress Concepts Views: 3 0 ratings Time: 00:30 More in Science & Technology
  • Astronomers Keeping an Eye on the Biggest Solar Flare in Nearly a Quarter Century
    Astronomers Keeping an Eye on the Biggest Solar Flare in Nearly a Quarter Century While the flare poses no threat to Earth, it could cause radio wave blackouts. Keep your Eye on the Biggest Solar Flare in Nearly a Quarter Century. Don't Miss the Biggest Solar Flare in... From: CatchTheAction Views: 1 0 ratings Time: 01:29 More in People & Blogs
  • Dear Astronomers! Take Note!
    Dear Astronomers! Take Note! Description. From: Higher Truth Channel Views: 3966 210 ratings Time: 05:03 More in News & Politics
  • Finding the new Earth [Full]
    Finding the new Earth [Full] Join astronomers in a race to find a planet that can sustain life. Amid all the space in the universe, is there another world like ours? Astronomers studying. Join astronomers in a race... From: BestFreeDocumentary DailyFreeDocumentary Views: 0 0 ratings Time: 45:01 More in Film & Animation
  • Bolide Fireball, a rare event that astronomers wait decades Video
    Bolide Fireball, a rare event that astronomers wait decades Video From: truevidoes Views: 0 0 ratings Time: 00:04 More in People & Blogs
  • Spanish astronomers discover two new planets in solar system
    Spanish astronomers discover two new planets in solar system From: Arglanodr Views: 0 0 ratings Time: 01:23 More in News & Politics
  • Astronomers discover most Earth like planet
    Astronomers discover most Earth like planet From: Arglanodr Views: 0 0 ratings Time: 00:58 More in News & Politics
  • Junior Astronomers | Live | 6th Annual Birthday Bash | Part 1 |HD|
    Junior Astronomers | Live | 6th Annual Birthday Bash | Part 1 |HD| Part 1 of Junior Astronomers at the Neighborhood Theater in Charlotte. Directed & Edited by Will Jones Junior Astronomers: Terrence Richard Philip Wheeler Co... From: Amplifier Video Views: 38 1 ratings Time: 07:12 More in People & Blogs
  • Georgia State astronomers image the exploding fireball stage of a nova
    Georgia State astronomers image the exploding fireball stage of a nova Georgia State astronomers image the exploding fireball stage of a nova. From: Ve3443 Views: 3 0 ratings Time: 03:26 More in People & Blogs
  • Freak frequency from outside the Milky Way baffles astronomers
    Freak frequency from outside the Milky Way baffles astronomers Are these mystery radio bursts messages from ALIENS? Freak frequency from outside the Milky Way baffles astronomers In 1967 British astronomer Jocelyn Bell B... From: Lorena Blake Views: 0 0 ratings Time: 00:53 More in People & Blogs
  • Asteroid to Pass Close to Earth as Astronomers Watc
    Asteroid to Pass Close to Earth as Astronomers Watc 150-foot asteroid to pass Friday, reminder that Earth could someday get hit. everything new on our channel, watch and subscribe https://www.youtube.com/channel/UChbqxKh5mM79zevZ8w5Xvqw. From: News 01 Views: 8 0 ratings Time: 02:04 More in News & Politics
  • Nibiru warning THE NIBIRU PAYOFF SCIENTISTS & ASTRONOMERS GAGGED WITH THREATS GOLDEN TICKETS & BRIBE
    Nibiru warning THE NIBIRU PAYOFF SCIENTISTS & ASTRONOMERS GAGGED WITH THREATS GOLDEN TICKETS & BRIBE Thanks for watching! Like===========Share===========Subscribe this links for more videos: https://www.youtube.com/channel/UC5dvQo7a0f0BYgVlDA9grjw **********... From: NIBIRU WARNING!!! Views: 18 0 ratings Time: 26:45 More in People & Blogs
  • ScienceCasts Andromeda vs the Milky Way Astronomers Predict a Titanic Collision SD
    ScienceCasts Andromeda vs the Milky Way Astronomers Predict a Titanic Collision SD From: Q3 Net Views: 0 0 ratings Time: 03:27 More in Science & Technology
  • Science Bulletins Backyard Astronomers Are Pros at Observing Jupiter
    Science Bulletins Backyard Astronomers Are Pros at Observing Jupiter From: Q3 Net Views: 0 0 ratings Time: 02:03 More in Science & Technology
  • Astronomers spot massive 'stellar quakes' ripping stars apart 15,000 light years away
    Astronomers spot massive 'stellar quakes' ripping stars apart 15,000 light years away Violent pulses are rocking the Milky Way: Astronomers spot massive 'stellar quakes' ripping stars apart 15000 light years away http://www.dailymail.co.uk/sc... From: All News Views: 4 0 ratings Time: 00:45 More in News & Politics
  • Astronomers discover two new families of alien comets
    Astronomers discover two new families of alien comets More videos at: http://adf.ly/t0vIN Read more at: http://news.sciencemag.org/space/2014/10/astronomers-discover-two-new-families-alien-comets. From: NewsNow Views: 0 0 ratings Time: 02:49 More in News & Politics
  • Astronomers accidentally discover brightest pulsar%2
    Astronomers accidentally discover brightest pulsar%2 CINCINNATI (WKRC) -- A pulsar is a rotating neutron star in space that beams with electromagnetic radiation. Although it may not look like much, a pulsar can... From: LOCAL 12 Views: 1 0 ratings Time: 00:42 More in News & Politics
  • Instruments Used By Astronomers
    Instruments Used By Astronomers Save Money on Amazon using this link! http://www.amazon.com/?tag=camcam0a8-20. From: More Jobs Views: 0 0 ratings Time: 01:22 More in Howto & Style
  • Ringed Asteroid Stuns Astronomers Space News
    Ringed Asteroid Stuns Astronomers Space News From: Madelyn1 Views: 0 0 ratings Time: 07:56 More in Entertainment

  •      Related Answers Results



























       

      Powered free by PHPmotion