Subscribe free to our newsletters via your
. 24/7 Space News .




EXO WORLDS
New Planet Orbits Backwards
by Staff Writers
Moffett Field CA (SPX) Aug 17, 2009


Planets are thought to form from disks of gas and dust orbiting stars, and typically orbit in the same direction that the star is spinning. Credit: NASA/JPL-Caltech

A team of scientists has found a new planet which orbits the wrong way around its host star. The planet, named WASP-17, and orbiting a star 1000 light years away, was found by the UK's WASP project in collaboration with Geneva Observatory. The discovery, which casts new light on how planetary systems form and evolve, was announced August 12 in a paper submitted to Astrophysical Journal.

Since planets form out of the same swirling gas cloud that creates a star, they are expected to orbit in the same direction that the star spins. Graduate students David Anderson, of Keele University, and Amaury Triaud, of Geneva Observatory, were surprised to find that WASP-17 is orbiting the wrong way, making it the first planet known to have a "retrograde" orbit. The likely explanation is that WASP-17 was involved in a near collision with another planet early in its history.

WASP-17 appears to have been the victim of a game of planetary billiards, flung into its unusual orbit by a close encounter with a "big brother" planet. Professor Coel Hellier, of Keele University, remarks: "Shakespeare said that two planets could no more occupy the same orbit than two kings could rule England; WASP-17 shows that he was right."

David Anderson added "Newly formed solar systems can be violent places. Our own moon is thought to have been created when a Mars-sized planet collided with the recently formed Earth and threw up a cloud of debris that turned into the moon. A near collision during the early, violent stage of this planetary system could well have caused a gravitational slingshot, flinging WASP-17 into its backwards orbit."

The first sign that WASP-17 was unusual was its large size. Though it is only half the mass of Jupiter it is bloated to nearly twice Jupiter's size, making it the largest planet known.

Astronomers have long wondered why some extra-solar planets are far bigger than expected, and WASP-17 points to the explanation. Scattered into a highly elliptical, retrograde orbit, it would have been subjected to intense tides. Tidal compression and stretching would have heated the gas-giant planet to its current, hugely bloated extent.

"This planet is only as dense as expanded polystyrene, seventy times less dense than the planet we're standing on", notes Hellier.

Professor Keith Mason, Chief Executive of the Science and Technology Facilities Council, which funded the research, said, "This is a fascinating new find and another triumph for the WASP team. Not only are they locating these far flung and mysterious planets but revealing more about how planetary systems, such as our own solar system, formed and evolved. The WASP team has proved once again why this project is currently the World's most successful project searching for transiting exoplanets."

WASP-17 is the 17th new exoplanet (planet outside our solar system) found by the Wide Area Search for Planets (WASP) consortium of UK universities. The WASP team detected the planet using an array of cameras that monitor hundreds of thousands of stars, searching for small dips in their light when a planet transits in front of them.

Geneva Observatory then measured the mass of WASP-17, showing that it was the right mass to be a planet. The WASP-South camera array that led to the discovery of WASP-17 is hosted by the South African Astronomical Observatory.

.


Related Links
Keele University
Lands Beyond Beyond - extra solar planets - news and science
Life Beyond Earth






Comment on this article via your Facebook, Yahoo, AOL, Hotmail login.

Share this article via these popular social media networks
del.icio.usdel.icio.us DiggDigg RedditReddit GoogleGoogle








EXO WORLDS
Huge New Planet Tells Of Game Of Planetary Billiards
London UK (SPX) Aug 13, 2009
A team of scientists has found a new planet which orbits the wrong way around its host star. The planet, named WASP-17, and orbiting a star 1000 light years away, was found by the UK's WASP project in collaboration with Geneva Observatory. The discovery, which casts new light on how planetary systems form and evolve, was announced in a paper submitted to Astrophysical Journal August 12. Si ... read more


EXO WORLDS
Moon May Light Man's Future

India Mulls Using Nuclear Energy To Power Chandrayaan II

Orbiting The Moon With Orion

Germany Shoots For The Moon By 2015

EXO WORLDS
Martian Dust Devil With Track And Shadow

Mars Orbiter Shows Angled View Of Martian Crater

Orbiter Safe After Computer Swap

Meteorite Found On Mars Yields Clues About Planet's Past

EXO WORLDS
NASA Completes Assembly Of Ares I-X Test Rocket

Rocket To Launch Inflatable Re-entry Capsule

First NASTAR Suborbital Space Scientist Training Course

TankHab: Living In A Gas Station

EXO WORLDS
Russia launches China communications satellite: report

China Conducts Stringent Tests Of Would-Be Spacemen

Chinese Astronauts Must Be Super Human

China bans bad breath in space: report

EXO WORLDS
Astronomy Question Of The Week: Why Do The Planets Break Ranks?

ESA Astronaut Andre Kuipers To Spend Six Months On The ISS Starting In 2011

Finnish President Receives Phone Call From Space

Name And Logo Unveiled For Christer Fuglesang Mission To The ISS

EXO WORLDS
Bad Weather Remains Main Obstacle To Timely Launch Of KSLV-1

Preparations Continue With The JCSAT-12 And Optus D3 Payloads For Next Ariane 5 Launch

ILS Proton Successfully Launches AsiaSat 5 Satellite

AsiaSat 5 Set For Launch

EXO WORLDS
New Planet Orbits Backwards

Huge New Planet Tells Of Game Of Planetary Billiards

Planet Smash-Up Sends Rock And Lava Flying

'Stunning' images of distant planet sent by Kepler scope

EXO WORLDS
Sony adopting industry standard for e-books

College e-textbooks go to class in iPhones

MEADS Receives Hardware Design Approvals, Enters System-Level CDR

Raytheon Develops World's Largest Infrared Light-Wave Detector




The content herein, unless otherwise known to be public domain, are Copyright 1995-2014 - Space Media Network. AFP, UPI and IANS news wire stories are copyright Agence France-Presse, United Press International and Indo-Asia News Service. ESA Portal Reports are copyright European Space Agency. All NASA sourced material is public domain. Additional copyrights may apply in whole or part to other bona fide parties. Advertising does not imply endorsement,agreement or approval of any opinions, statements or information provided by Space Media Network on any Web page published or hosted by Space Media Network. Privacy Statement