[meteorite-list] WISE Captures Key Image Of Comet Mission's Destination (Comet Hartley 2)

[Ron Baalke]

Oct. 5, 2010

J.D. Harrington 
Headquarters, Washington 
202-358-5241 
j.d.harrington at nasa.gov 

Whitney Clavin 
Jet Propulsion Laboratory, Pasadena, Calif. 
818-354-4673 
whitney.clavin at jpl.nasa.gov 

RELEASE: 10-249

WISE CAPTURES KEY IMAGE OF COMET MISSION'S DESTINATION

WASHINGTON -- NASA's Wide-field Infrared Survey Explorer, or WISE, 
caught a glimpse of the comet that the agency's EPOXI mission will 
visit in November. The WISE observation will help the EPOXI team put 
together a large-scale picture of the comet, known as Hartley 2. 

"WISE's infrared vision provides data that complement what EPOXI will 
see with its visible-light and near-infrared instruments," said James 
Bauer, of NASA's Jet Propulsion Laboratory, Pasadena, Calif. "It's as 
if WISE can see an entire country, and EPOXI will visit its capital." 

WISE's infrared vision will allow the telescope to get a new estimate 
of the size of the comet's nucleus, or core, as well as a more 
thorough look at the sizes of dust particles that surround it. This 
information, when combined with what EPOXI finds as it gets closer to 
Hartley 2, will reveal how the comet has changed over time. 

The WISE image is available at: 

http://www.nasa.gov/mission_pages/WISE/multimedia/gallery/pia13438.html 

On Nov. 4, the EPOXI mission, which uses the already "in flight" Deep 
Impact flyby spacecraft, will reach its closet approach to Hartley 2. 
The spacecraft will examine the dusty, icy body in detail as it flies 
by, providing the best, extended view of a comet in history. WISE and 
several other ground- and space-based telescopes are participating in 
the viewing, working together to tackle mysteries about our solar 
system's origins that are frozen inside comets. 

For stargazers, opportunities to view the comet are possible 
throughout October. On Wednesday, Oct. 20, Hartley 2 will reach its 
closest approach to Earth since it was discovered in 1986. The comet 
will be approximately 11 million miles away and should be visible 
with the naked eye near the constellation Perseus if viewed in dark 
skies. Observers will need binoculars or telescopes from urban areas 
in the Northern Hemisphere. Southern Hemisphere stargazers can see 
the comet later in the month. 

WISE captured its view of the comet during an ongoing scan of the sky 
in infrared light. The mission has been busy cataloging hundreds of 
millions of objects, from comets to distant, powerful galaxies. In 
late September, it used up its frozen cryogen coolant as expected and 
began a new phase of its survey. Called the NEOWISE Post-Cryogenic 
Mission, it primarily focuses on finding additional asteroids and 
comets. To date, the WISE mission has observed more than 150,000 
asteroids and 110 comets, including Hartley 2. 

"Astronomers can reference our catalog to get detailed infrared data 
about their favorite asteroid or comet," said Amy Mainzer, the 
principal investigator of NEOWISE at JPL. "Space missions can also 
use our observations for more information on their targets, as EPOXI 
is doing." 

WISE's view of Hartley 2 was taken on May 10, 2010. It gives 
astronomers a unique look at the comet, complementing what other 
telescopes can see. Because WISE scanned the whole sky, it captured 
the most extensive view of Hartley 2's trail, the dusty path left by 
the comet on its repeated journey around the sun. 

Bauer said, "We want to know how the comet behaves as it comes toward 
the sun and out of deep freeze. The WISE image is one critical puzzle 
piece of many that will give a comprehensive view of the behavior of 
the comet through the time of the encounter." 

The comet started to show signs of activity in the spring, spitting 
out gas and dust. By July, there were clear jets of gas. "Comparing 
the dust early on to what we see later with EPOXI helps us understand 
how the activity started on Hartley 2," said Michael A'Hearn, the 
principal investigator of EPOXI at the University of Maryland in 
College Park. 

The term EPOXI is a combination of the names for the two extended 
mission components: the Extrasolar Planet Observations and 
Characterization (EPOCh), and the Hartley 2 flyby, called the Deep 
Impact eXtended Investigation (DIXI). The name NEOWISE comes from 
combining WISE and the acronym for near-Earth object, NEO. 

For more information about EPOXI, visit: 

http://www.nasa.gov/epoxi 

http://epoxi.umd.edu/ 

For more information about WISE, visit: 

http://www.nasa.gov/wise 

http://wise.astro.ucla.edu/ 
	
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