Photobucket - Video and Image Hosting Photobucket - Video and Image Hosting Photobucket - Video and Image Hosting "Bold is the ship bound for Alpha Centauri, nothing can turn it around..." Since Star Trek has not yet become a reality, we must ride the bold spaceship of our imagination and view the wonders of the universe through pictures taken by telescopes. Thanks to Hubble and others, we can emulate Captain Picard and say, "Let's see what's out there." Glories and Wonders! How great Thou art!
  • Mad is the Captain of Alpha Centauri; We must be out of our minds. Still we are shipmates bound for tomorrow, and everyone here's flying blind. Mad is the crew bound for Alpha Centauri, Dreamers and poets and clowns. Bold is the crew bound for Alpha Centauri; nothing can turn it around. Oh, we must believe in magic; we must believe in the guiding hand. If you believe in magic, you'll have the universe at your command. Artist:Crystal Gayle; album UNKNOWN
  • Saturday, October 31, 2009


    Do We Have Neighbors?

    32 exoplanets found

    A planet six times as massive as Earth orbits the star Gliese 667 C (not pictured) while two companion stars lie in the distance in an artist's conception.

    The low-mass planet is one of 32 planets found outside our solar system over the past five years, astronomers announced in October 2009. The find increases the number of known "exoplanets" to more than 400.

    New-planet picture courtesy ESO/L. Calçada

    32 New Planets Found Outside Our Solar System

    October 19, 2009

    Astronomers have added 32 new planets to the list of planets found orbiting stars outside our solar system.

    The discoveries, announced today at a press briefing in Portugal, increase to more than 400 the number of known extrasolar planets, or "exoplanets."

    The 32 previously unseen planets range from five times the mass of Earth up to eight times the mass of Jupiter, scientists said.

    In addition, the new planets were found around different types of stars, challenging existing theories for where and how planets form.

    Overall, the research suggests that 40 to 60 percent of all planetary systems in the universe contain low-mass planets.

    Since lower masses most likely mean Earthlike sizes, such planets are considered to be the best candidates in the search for extraterrestrial life. (Related pictures: "3 Worlds Most Likely to Harbor Life Named.")

    "The models are predicting even larger numbers of low-mass planets like Earth, so I am pretty confident that there are Earth-type planets everywhere," said team member Stephane Udry of the Observatory of Geneva in Switzerland.

    "Nature doesn't like a vacuum," he added, "so if there is space to put a planet, it will put the planet there."

    New Planets: Super-Earths, Gas Giants

    The 32 new planets were found over the past five years using an instrument called a spectrograph at the European Southern Observatory in La Silla, Chile.

    Known as HARPS, for High Accuracy Radial velocity Planetary Searcher, the spectrograph detects wobbles in a star's orbit caused by the pull of an unseen exoplanet.

    The HARPS team selected stars like our sun, as well as lower-mass dwarf stars, to watch for wobbles.

    Red dwarf stars were targets because they are dimmer, low-mass stars, which makes it easier to detect wobbles from low-mass satellite planets, said team member Nuno Santos, of the University of Porto, Portugal.

    The 32 newfound exoplanets include several super-Earths, such as two planets no more than five times Earth's mass and two about six times Earth's mass, the Observatory of Geneva's Udry said.

    The largest newly discovered exoplanet is a monster at seven to eight times Jupiter's mass, he estimated.

    In addition, several Jupiter-mass planets were found around stars that don't have many metals.

    Previous theories had stated that planets wouldn't tend to form around metal-poor stars, since planets are thought to take shape inside the metal-filled disks of debris left over from stellar birth.

    The new finds suggest that astronomers might need to revise theories of planet formation—and may increase the number of possible star systems in the universe.

    (Related: "Turbulence Key to Planet Formation, New Study Suggests.")

    Exact details about each of the 32 new planets have yet to be published, Udry said, but "a bunch of the new planets will be described in the next six months."

    Planets and Habitability: The Next Step

    Counting the 32 new planets, the HARPS instrument has so far helped astronomers find 75 of the roughly 400 known exoplanets.

    For example, a team using HARPS had previously found several low-mass planets orbiting Gliese 581, a red dwarf star some 20.5 light-years away.

    One of these planets, Gliese 581 c, has been touted as the first Earthlike planet yet found outside the solar system.

    But for most of the newly revealed exoplanets, appraisals of their habitability will probably have to wait, the team said.

    "It will be very difficult to confirm a planet detected [by HARPS] is the size of the Earth and that it would also be in the habitable zone," Udry said.

    "We need the next generation of radio-velocity machine to do that," he said, adding that such a device should be ready in the next five years.



    Comments: Post a Comment

    Links to this post:

    Create a Link

    << Home


    June 2006   July 2006   September 2006   November 2006   December 2006   January 2007   February 2007   March 2007   April 2007   May 2007   June 2007   July 2007   November 2007   December 2007   January 2008   February 2008   March 2008   April 2008   May 2008   June 2008   July 2008   September 2008   October 2008   November 2008   December 2008   January 2009   February 2009   March 2009   April 2009   July 2009   August 2009   September 2009   October 2009   November 2009   December 2009  

    This page is powered by Blogger. Isn't yours?