NASA : NASA's Hubble Space Telescope Spots Mars-Bound Comet Sprout Multiple Jets

The images above show -- before and after filtering -- comet C/2013 A1, also known as Siding Spring, as captured by Wide Field Camera 3 on NASA's Hubble Space Telescope.

Image Credit:

NASA, ESA, and J.-Y. Li (Planetary Science Institute)

NASA released Thursday an image of a comet that, on Oct. 19, will pass within 84,000 miles of Mars -- less than half the distance between Earth and our moon.

The image on the left, captured March 11 by NASA's Hubble Space Telescope, shows comet C/2013 A1, also called Siding Spring, at a distance of 353 million miles from Earth. Hubble can't see Siding Spring's icy nucleus because of its diminutive size. The nucleus is surrounded by a glowing dust cloud, or COMA, that measures roughly 12,000 miles across.

The right image shows the comet after image processing techniques were applied to remove the hazy glow of the coma revealing what appear to be two jets of dust coming off the location of the nucleus in opposite directions. This observation should allow astronomers to measure the direction of the nucleus’s pole, and axis of rotation.

Hubble also observed Siding Spring on Jan. 21 as Earth was crossing its orbital plane, which is the path the comet takes as it orbits the sun. This positioning of the two bodies allowed astronomers to determine the speed of the dust coming off the nucleus.

"This is critical information that we need to determine whether, and to what degree, dust grains in the coma of the comet will impact Mars and spacecraft in the vicinity of Mars," said Jian-Yang Li of the Planetary Science Institute in Tucson, Arizona.

Discovered in January 2013 by Robert H. McNaught at Siding Spring Observatory, the comet is falling toward the sun along a roughly 1 million year orbit and is now within the radius of Jupiter's orbit. The comet will make its closest approach to our sun on Oct. 25, at a distance of 130 million miles – well outside of Earth's orbit. The comet is not expected to become bright enough to be seen by the naked eye.

The Hubble Space Telescope is a project of international cooperation between NASA and the European Space Agency. NASA's Goddard Space Flight Center in Greenbelt, Md., manages the telescope. The Space Telescope Science Institute (STScI) in Baltimore conducts Hubble science operations. STScI is operated for NASA by the Association of Universities for Research in Astronomy, Inc., in Washington.

For images and more information about Hubble, visit:

http://www.nasa.gov/hubble

NASA

Guillermo Gonzalo Sánchez Achutegui

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ASTRONOMY: Comet Hartley 2 Leaves a Bumpy Trail

Hi my Friends: A VUELO DE UN QUINDE EL BLOG.,The comet, known officially as 103P/Hartley was discovered fairly recently, in 1986, by Malcolm Hartley in Siding Spring, Australia. It probably originated from an icy orbit close to that of Jupiter's, before something knocked it on a path toward the sun. The comet circles the sun every 6.46 years -- its upcoming closest approach to the sun, called perihelion, will take place on Oct. 28, 2011. EPOXI, which utilizes the already "in flight" Deep Impact flyby spacecraft, will reach the comet on Nov. 4.

Icy Visitor from Beyond
This visitor from deep space, seen here by NASA's Wide-field Infrared Survey Explorer, or WISE, is comet Hartley 2 -- the destination for NASA's EPOXI mission.

The comet, known officially as 103P/Hartley was discovered fairly recently, in 1986, by Malcolm Hartley in Siding Spring, Australia. It probably originated from an icy orbit close to that of Jupiter's, before something knocked it on a path toward the sun. The comet circles the sun every 6.46 years -- its upcoming closest approach to the sun, called perihelion, will take place on Oct. 28, 2011. EPOXI, which utilizes the already "in flight" Deep Impact flyby spacecraft, will reach the comet on Nov. 4.

The WISE observations are helping the EPOXI team gain a more comprehensive picture of the comet's behavior over time. This image, taken on May 10, 2010, provides the most extensive look yet at the comet's dusty trail -- a path of particles, sort of like a trail of crumbs, that the comet leaves during each of its trips through the inner solar-system. The extent of the trail seen in this view, behind the comet, is 1.8 million kilometers, or 1.1 million miles.

WISE's infrared vision also makes it good at studying the range of dust particle sizes in the trail, as well as the comet's tail, seen here as a fuzzy streak to the right of the comet, in line with the trail. Infrared observations are also useful for measuring the comet's nucleus and rotation rate.

Comet Hartley 2 is about 1.2 kilometers in diameter, or .8 miles. It was approximately 2.3 astronomical units away from the sun when this picture was taken (an astronomical unit is the distance between Earth and the sun). When EPOXI reaches the comet on Nov. 4, it will be nearly 1.1 astronomical units away from the sun and only 0.15 astronomical units from Earth.

The fuzzy background in this picture is noise, primarily from dust in our own solar system. Stars cannot be seen because they are subtracted out during the process of averaging multiple WISE pictures together into this one view.
Infrared light of 4.6, 12 and 22 microns is colored blue, green and red, respectively.
Image 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. An abstract of the scientific paper is online at http://arxiv.org/abs/1107.2637, with the option of downloading a full PDF.

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 .

Guillermo Gonzalo Sanchez Achutegui
ayabaca@gmail.com
ayabaca@hotmail.com
ayabaca@yahoo.com
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