[meteorite-list] Hubble Space Telescope discovers 4th moon around Pluto

[Matson, Robert D.]

Hi All,

Pluto has a 4th moon!  Here's a link to the CBAT:

http://www.cbat.eps.harvard.edu/cbet/cbet002769.txt

Below is the NASA News release:

July 20, 2011

Trent J. Perrotto 
Headquarters, Washington      
trent.j.perrotto at nasa.gov   
202-358-0321 

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

Karen Randall 
SETI Institute, Mountain View, Calif. 
krandall at seti.org   
650-960-4537 


RELEASE: 11-234

NASA'S HUBBLE DISCOVERS ANOTHER MOON AROUND PLUTO

WASHINGTON -- Astronomers using the Hubble Space Telescope discovered 
a fourth moon orbiting the icy dwarf planet Pluto. The tiny, new 
satellite, temporarily designated P4, was uncovered in a Hubble 
survey searching for rings around the dwarf planet. 

The new moon is the smallest discovered around Pluto. It has an 
estimated diameter of 8 to 21 miles (13 to 34 km). By comparison, 
Charon, Pluto's largest moon, is 648 miles (1,043 km) across, and the 
other moons, Nix and Hydra, are in the range of 20 to 70 miles in 
diameter (32 to 113 km). 

"I find it remarkable that Hubble's cameras enabled us to see such a 
tiny object so clearly from a distance of more than 3 billion miles 
(5 billion km)," said Mark Showalter of the SETI Institute in 
Mountain View, Calif., who led this observing program with Hubble. 

The finding is a result of ongoing work to support NASA's New Horizons 
mission, scheduled to fly through the Pluto system in 2015. The 
mission is designed to provide new insights about worlds at the edge 
of our solar system. Hubble's mapping of Pluto's surface and 
discovery of its satellites have been invaluable to planning for New 
Horizons' close encounter. 

"This is a fantastic discovery," said New Horizons' principal 
investigator Alan Stern of the Southwest Research Institute in 
Boulder, Colo. "Now that we know there's another moon in the Pluto 
system, we can plan close-up observations of it during our flyby." 

The new moon is located between the orbits of Nix and Hydra, which 
Hubble discovered in 2005. Charon was discovered in 1978 at the U.S. 
Naval Observatory and first resolved using Hubble in 1990 as a 
separate body from Pluto. 

The dwarf planet's entire moon system is believed to have formed by a 
collision between Pluto and another planet-sized body early in the 
history of the solar system. The smashup flung material that 
coalesced into the family of satellites observed around Pluto. 

Lunar rocks returned to Earth from the Apollo missions led to the 
theory that our moon was the result of a similar collision between 
Earth and a Mars-sized body 4.4 billion years ago. Scientists believe 
material blasted off Pluto's moons by micrometeoroid impacts may form 
rings around the dwarf planet, but the Hubble photographs have not 
detected any so far. 

"This surprising observation is a powerful reminder of Hubble's 
ability as a general purpose astronomical observatory to make 
astounding, unintended discoveries," said Jon Morse, astrophysics 
division director at NASA Headquarters in Washington. 

P4 was first seen in a photo taken with Hubble's Wide Field Camera 3 
on June 28. It was confirmed in subsequent Hubble pictures taken on 
July 3 and July 18. The moon was not seen in earlier Hubble images 
because the exposure times were shorter. There is a chance it 
appeared as a very faint smudge in 2006 images, but was overlooked 
because it was obscured. 

Hubble 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   

and 

http://hubblesite.org/news/2011/23   
	
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