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Comet Hartley 2 leaves a bumpy trail

Date:
July 18, 2011
Source:
NASA/Jet Propulsion Laboratory
Summary:
New findings from NEOWISE, the asteroid- and comet-hunting portion of NASA's Wide-field Infrared Survey Explorer mission, show that comet Hartley 2 leaves a pebbly trail as it laps the sun, dotted with grains as big as golf balls.
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Comet Hartley 2 as seen by WISE. Data from the infrared telescope revealed that the comet's trail, seen here as the long, thin yellow line, consists of particles as large as golf balls.
Credit: NASA/JPL-Caltech/UCLA

New findings from NEOWISE, the asteroid- and comet-hunting portion of NASA's Wide-field Infrared Survey Explorer mission, show that comet Hartley 2 leaves a pebbly trail as it laps the sun, dotted with grains as big as golf balls.

Previously, NASA's EPOXI mission, which flew by the comet on Nov. 4, 2010, found golf ball- to basketball-sized fluffy ice particles streaming off comet Hartley 2. NEOWISE data show that the golf ball-sized chunks survive farther away from the comet than previously known, winding up in Hartley 2's trail of debris. The NEOWISE team determined the size of these particles by looking at how far they deviated from the trail. Larger particles are less likely to be pushed away from the trail by radiation pressure from the sun.

The observations also show that the comet is still actively ejecting carbon dioxide gas at a distance of 2.3 astronomical units from the sun, which is farther away from the sun than where EPOXI detected carbon dioxide jets streaming from the comet. An astronomical unit is the average distance between Earth and the sun.

"We were surprised that carbon dioxide plays a significant role in comet Hartley 2's activity when it's farther away from the sun," said James Bauer, the lead author of a new paper on the result in the Astrophysical Journal.

JPL manages and operates the Wide-field Infrared Survey Explorer for NASA's Science Mission Directorate, Washington. The principal investigator, Edward Wright, is at UCLA. The mission was competitively selected under NASA's Explorers Program managed by the Goddard Space Flight Center, Greenbelt, Md. The science instrument was built by the Space Dynamics Laboratory, Logan, Utah, and the spacecraft was built by Ball Aerospace & Technologies Corp., Boulder, Colo. Science operations and data processing take place at the Infrared Processing and Analysis Center at the California Institute of Technology in Pasadena. Caltech manages JPL for NASA.

More information is online at http://www.nasa.gov/wise , http://wise.astro.ucla.edu and http://jpl.nasa.gov/wise .


Story Source:

The above post is reprinted from materials provided by NASA/Jet Propulsion Laboratory. Note: Materials may be edited for content and length.


Journal Reference:

  1. James M. Bauer, Russell G. Walker, A. K. Mainzer, Joseph R. Masiero, Tommy Grav, John W. Dailey, Robert S. McMillan, Carey M. Lisse, Yan R. Fernández, Karen J. Meech, Jana Pittichova, Erin K. Blauvelt, Frank J. Masci, Michael F. A'Hearn, Roc M. Cutri, James V. Scotti, David J. Tholen, Emily DeBaun, Ashlee Wilkins, Emma Hand, Edward L. Wright, the WISE Collaboration. WISE/NEOWISE observations of comet 103P/Hartley 2. Astrophysical Journal, 2011; (accepted) [link]

Cite This Page:

NASA/Jet Propulsion Laboratory. "Comet Hartley 2 leaves a bumpy trail." ScienceDaily. ScienceDaily, 18 July 2011. <www.sciencedaily.com/releases/2011/07/110718001336.htm>.
NASA/Jet Propulsion Laboratory. (2011, July 18). Comet Hartley 2 leaves a bumpy trail. ScienceDaily. Retrieved July 28, 2015 from www.sciencedaily.com/releases/2011/07/110718001336.htm
NASA/Jet Propulsion Laboratory. "Comet Hartley 2 leaves a bumpy trail." ScienceDaily. www.sciencedaily.com/releases/2011/07/110718001336.htm (accessed July 28, 2015).

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