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




EXO WORLDS
NASA Finds Earth-Size Planet Candidates In Habitable Zone
by Michael Mewhinney and Rachel Hoover
Moffett Field CA (SPX) Feb 04, 2011


Kepler's planet candidates by size. Image credit: NASA/Wendy Stenzel. For a larger version of this image please go here.

Is our Milky Way galaxy home to other planets the size of Earth? Are Earth-sized planets common or rare? NASA scientists seeking answers to those questions recently revealed their discovery.

"We went from zero to 68 Earth-sized planet candidates and zero to 54 candidates in the habitable zone - a region where liquid water could exist on a planet's surface. Some candidates could even have moons with liquid water," said William Borucki of NASA's Ames Research Center, Moffett Field, Calif., and the Kepler Mission's science principal investigator.

"Five of the planetary candidates are both near Earth-size and orbit in the habitable zone of their parent stars."

Planet candidates require follow-up observations to verify they are actual planets.

"We have found over twelve hundred candidate planets - that's more than all the people have found so far in history," said Borucki. "Now, these are candidates, but most of them, I'm convinced, will be confirmed as planets in the coming months and years."

The findings increase the number of planet candidates identified by Kepler to-date to 1,235. Of these, 68 are approximately Earth-size; 288 are super-Earth-size; 662 are Neptune-size; 165 are the size of Jupiter and 19 are larger than Jupiter. Of the 54 new planet candidates found in the habitable zone, five are near Earth-sized.

The remaining 49 habitable zone candidates range from super-Earth size - up to twice the size of Earth - to larger than Jupiter. The findings are based on the results of observations conducted May 12 to Sept. 17, 2009 of more than 156,000 stars in Kepler's field of view, which covers approximately 1/400 of the sky.

"The fact that we've found so many planet candidates in such a tiny fraction of the sky suggests there are countless planets orbiting stars like our sun in our galaxy," said Borucki.

"Kepler can find only a small fraction of the planets around the stars it looks at because the orbits aren't aligned properly. If you account for those two factors, our results indicate there must be millions of planets orbiting the stars that surround our sun."

"We're about half-way through Kepler's scheduled mission," said Roger Hunter, the Kepler project manager. "The announcement is very exciting and portends many discoveries to come. It's looking like the galaxy may be littered with many planets."

Among the stars with planetary candidates, 170 show evidence of multiple planetary candidates, including one, Kepler-11, that scientists have been able to confirm that has no fewer than six planets.

"Another exciting discovery has been the tremendous variations in the structure of the confirmed planets - some have the density of Styrofoam and others are denser than iron. The Earth's density is in between."

"The historic milestones Kepler makes with each new discovery will determine the course of every exoplanet mission to follow," said Douglas Hudgins, Kepler program scientist at NASA Headquarters in Washington.

Kepler, a space telescope, looks for planet signatures by measuring tiny decreases in the brightness of stars caused by planets crossing in front of them - this is known as a transit.

Since transits of planets in the habitable zone of sun-like stars occur about once a year and require three transits for verification, it is expected to take three years to locate and verify Earth-size planets orbiting sun-like stars.

The Kepler science team uses ground-based telescope and the Spitzer Space Telescope to perform follow-up observations on planetary candidates and other objects of interest found with the spacecraft.

The star field that Kepler observes in the constellations Cygnus and Lyra can only be seen from ground-based observatories in spring through early fall. The data from these other observations helps determine which of the candidates can be validated as planets.

"The first four months of data have given us an enormous amount of interesting information for the science community to explore and to find the planets among the candidates that we have found," said Borucki. "Keep in mind, in the future, we'll have even more data for small planets in and near the habitable zone for everyone to look at."

Kepler will continue conducting science operations until at least November 2012, searching for planets as small as Earth, including those that orbit stars in a warm habitable zone where liquid water could exist on the surface of the planet.

Since transits of planets in the habitable zone of solar-like stars occur about once a year and require three transits for verification, it is expected to take three years to locate and verify Earth-size planets orbiting sun-like stars.

Borucki predicted that the search using the Kepler spacecraft's continuous and long-duration capability will significantly enhance scientists' ability to determine the distributions of planet size and orbital period in the future.

"In the coming years, Kepler's capabilities will allow us to find Earth-size planets in the habitable zone of other stars," Borucki said. "Future missions will be developed to study the composition of planetary atmospheres to determine if they are compatible with the presence of life. The design for these missions depends of Kepler finding whether Earth-size planets in the habitable zone are common or rare."

The Kepler Mission team has discovered a total of 15 exoplanets, including the smallest known exoplanet, Kepler-10b.

"Kepler is providing data 100 times better than anyone has ever done before," said Borucki.

"It's exploring a new part of phase space, a new part of the universe that could not be explored without this kind of precision, so it's producing absolutely beautiful data. We're seeing the variability of stars like no one has ever seen before. We're finding planets smaller than anyone has ever seen before, because the data quality is extremely good."

"In one generation we have gone from extraterrestrial planets being a mainstay of science fiction, to the present, where Kepler has helped turn science fiction into today's reality," said NASA Administrator Charles Bolden. "These discoveries underscore the importance of NASA's science missions, which consistently increase understanding of our place in the cosmos."

.


Related Links
Kepler Mission Section
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




Memory Foam Mattress Review
Newsletters :: SpaceDaily :: SpaceWar :: TerraDaily :: Energy Daily
XML Feeds :: Space News :: Earth News :: War News :: Solar Energy News





EXO WORLDS
A Six-Planet System
Moffett Field CA (SPX) Feb 04, 2011
A remarkable planetary system discovered by NASA's Kepler mission has six planets around a Sun-like star, including five small planets in tightly packed orbits. Astronomers at the University of California, Santa Cruz, and their coauthors analyzed the orbital dynamics of the system, determined the sizes and masses of the planets, and figured out their likely compositions - all based on Kepl ... read more


EXO WORLDS
NASA's New Lander Prototype Skates Through Integration And Testing

Draper Commits One Million Dollars To Next Giant Leap's Moon Lander

Lunar water may have come from comets - scientists

Moon Has Earth-Like Core

EXO WORLDS
Martian Sand Dunes Re-Sculpted Regularly

Rover Staying Busy While Mars Is Behind The Sun

Rare Meteorites Reveal Mars Collision Caused Water Flow

Fleet Of INL-Designed Mars Hoppers Could Swiftly Explore Other Worlds

EXO WORLDS
Lifting To Space

Shot US lawmaker's husband to return to space

Report warns of wireless radiation risks

Watch Out For Solar Sail Flares

EXO WORLDS
Slow progress in U.S.-China space efforts

China Builds Theme Park In Spaceport

Tiangong Space Station Plans Progessing

China-Made Satellite Keeps Remote Areas In Venezuela Connected

EXO WORLDS
Europe's ATV Space Ferry Ready For Launch

Intensive Preparations For ATV Freighter Launch To ISS

Russian Space Freighter Progress M-09M Docks With ISS

Crew Attaches Japanese Resupply Vehicle To ISS

EXO WORLDS
Activities At Esrange Space Center 2011

Russia Plans To Build Carrier Rocket For Mars Missions

First Delta IV Heavy Launches From Vandenberg

Beaming Rockets Into Space

EXO WORLDS
NASA Finds Earth-Size Planet Candidates In Habitable Zone

Las Cumbres Scientists Play Key Role In New Planetry System Discovery

A Six-Planet System

Earth-Size Planet Candidates Found In Habitable Zone

EXO WORLDS
Verizon reins in data hogs before unleashing iPhone

Air Laser May Sniff Bombs, Pollutants From A Distance

85 percent of US adults own cellphone: survey

New York Times net profit dips 26 percent




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