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




IRON AND ICE
WISE Mission Finds First Trojan Asteroid Sharing Earth Orbit
by Staff Writers
Pasadena CA (JPL) Jul 28, 2011


Asteroid 2010 TK7 is circled in green, in this single frame taken by NASA's Wide-field Infrared Survey Explorer, or WISE. The majority of the other dots are stars or galaxies far beyond our solar system. Astronomers discovered this object - the first known Earth Trojan asteroid - after sifting through asteroid candidates identified by WISE. This image was taken in infrared light at a wavelength of 4.6 microns in Oct. 2010. Image credit: NASA JPL-Caltech UCLA.

Astronomers studying observations taken by NASA's Wide-field Infrared Survey Explorer (WISE) mission have discovered the first known "Trojan" asteroid orbiting the sun along with Earth.

Trojans are asteroids that share an orbit with a planet near stable points in front of or behind the planet. Because they constantly lead or follow in the same orbit as the planet, they never can collide with it. In our solar system, Trojans also share orbits with Neptune, Mars and Jupiter. Two of Saturn's moons share orbits with Trojans.

Scientists had predicted Earth should have Trojans, but they have been difficult to find because they are relatively small and appear near the sun from Earth's point of view.

"These asteroids dwell mostly in the daylight, making them very hard to see," said Martin Connors of Athabasca University in Canada, lead author of a new paper on the discovery in the July 28 issue of the journal Nature.

"But we finally found one, because the object has an unusual orbit that takes it farther away from the sun than what is typical for Trojans. WISE was a game-changer, giving us a point of view difficult to have at Earth's surface."

The WISE telescope scanned the entire sky in infrared light from January 2010 to February 2011. Connors and his team began their search for an Earth Trojan using data from NEOWISE, an addition to the WISE mission that focused in part on near-Earth objects, or NEOs, such as asteroids and comets.

NEOs are bodies that pass within 28 million miles (45 million kilometers) of Earth's path around the sun. The NEOWISE project observed more than 155,000 asteroids in the main belt between Mars and Jupiter, and more than 500 NEOs, discovering 132 that were previously unknown.

The team's hunt resulted in two Trojan candidates. One called 2010 TK7 was confirmed as an Earth Trojan after follow-up observations with the Canada-France-Hawaii Telescope on Mauna Kea in Hawaii.

The asteroid is roughly 1,000 feet (300 meters) in diameter. It has an unusual orbit that traces a complex motion near a stable point in the plane of Earth's orbit, although the asteroid also moves above and below the plane. The object is about 50 million miles (80 million kilometers) from Earth.

The asteroid's orbit is well-defined and for at least the next 100 years, it will not come closer to Earth than 15 million miles (24 million kilometers).

An animation showing the orbit is available here.

"It's as though Earth is playing follow the leader," said Amy Mainzer, the principal investigator of NEOWISE at NASA's Jet Propulsion Laboratory in Pasadena, Calif. "Earth always is chasing this asteroid around."

A handful of other asteroids also have orbits similar to Earth. Such objects could make excellent candidates for future robotic or human exploration. Asteroid 2010 TK7 is not a good target because it travels too far above and below the plane of Earth's orbit, which would require large amounts of fuel to reach it.

"This observation illustrates why NASA's NEO Observation program funded the mission enhancement to process data collected by WISE," said Lindley Johnson, NEOWISE program executive at NASA Headquarters in Washington. "We believed there was great potential to find objects in near-Earth space that had not been seen before."

NEOWISE data on orbits from the hundreds of thousands of asteroids and comets it observed are available through the NASA-funded International Astronomical Union's Minor Planet Center at the Smithsonian Astrophysical Observatory in Cambridge, Mass.

.


Related Links
WISE
Asteroid and Comet Mission News, Science and Technology






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





IRON AND ICE
MIT students to build imaging instrument to fly aboard mission to an asteroid
Boston MA (SPX) Jul 27, 2011
The asteroid 1999 RQ36 may not be a household name, but astronomers predict that in less than 200 years, it may make an unforgettable impact. According to radar and optical observations, the space rock, measuring some five football fields in diameter, has a 1 in 1,000 chance of crashing into Earth in the year 2182. Astronomers are also interested in the asteroid's potential to reveal clues ... read more


IRON AND ICE
Unique volcanic complex discovered on Lunar far side

Moon Express Announces Dr. Alan Stern as Chief Scientist

Northrop Grumman Honored by IEEE for Development of Lunar Module

Two NASA Probes Tackle New Mission: Studying The Moon

IRON AND ICE
NASA's Next Mars Rover to Land at Gale Crater

Opportunity Closing In On Spirit Point At Endeavour Crater

MAVEN Mission Completes Major Milestone

NASA says Mars mountain will read like 'a great novel'

IRON AND ICE
SwRI suborbital astronaut payload specialists move to flight planning phase, release mission patch

Graybiel Lab poised for next chapter of space exploration

Space Program Mavens Comment on the Future of Space Exploration

This Time It's Both Rocket Science AND Surgery

IRON AND ICE
Spotlight Time for Tiangong

China launches new data relay satellite

Time Enough for Tiangong

China launches experimental satellite

IRON AND ICE
New uses for Space Station

ISS to be sunk after 2020: Russian space agency

Certification for ISS onboard astronaut

NASA and International Partners Discuss New Uses for Space Station

IRON AND ICE
Russia sends observation satellite into space

NASA inks agreement with maker of Atlas V rocket

Russia launches 2 foreign satellites into orbit

ILS Proton Successfully Launches the SES-3 Satellite for SES

IRON AND ICE
Exoplanet Aurora Makes For An Out-of-this-World Sight

Distant planet aurorae modeled

Exoplanet Aurora: An Out-of-this-World Sight

Ten new distant planets detected

IRON AND ICE
Turksat turns to GMV for control of its satellites

Lockheed Martin's Multi-Mission Signal Processor Completes Tracking Test

Sharper deeper faster 3D imaging

Rare Coupling of Magnetic and Electric Properties in a Single Material




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