[meteorite-list] NASA's Hubble Space Telescope Spots Mars-Bound Comet Sprout Multiple Jets (C/2013 A1)

[Ron Baalke]

March 27, 2014

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

[Images]
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

-end-

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

Ray Villard
Space Science Telescope Institute, Baltimore, Md.
410-338-4493 / 410-338-4514
Villard at stsci.edu