Astronomers using the Hubble Space Telescope think they may have identified two previously unknown moons orbiting Pluto.
The candidate moons are around 5,000 times fainter than Pluto, and appear to orbit the planet at a distance of around 27,000 miles, two to three times as far away as Pluto's confirmed moon Charon. The possible satellites were first imaged on 15 May 2005 with follow up images taken three days later.
http://www.theregister.co.uk/2005/11/01/pluto_moons/
see also http://science.nasa.gov/headlines/y2005/01nov_moonsofpluto.htm?list193774
http://blogs.discovermagazine.com/badastronomy/2008/10/28/amateur-astronomers-capture-jupiter-charon/
That'd make an interesting astrophotography challenge. ;)
Getting an image of Pluto is relatively easy to do. However, getting Charon as well would need a very long focal length, a large aperture, a damn good camera and excellent seeing. 0.7" would need a superb resolution and conditions to take a picture of it.
Pluto, the runt of the solar system, is still a mystery to astronomers in many ways. But thanks to a new study of the dwarf planet's atmosphere, this misunderstood place is a little more known to us now.
Using the European Southern Observatory's (ESO) Very Large Telescope in Chile, researchers made the first ever quantitative measurement of the chemical composition of the atmosphere around Pluto. The study revealed that the dwarf planet's air is warmer, and contains more methane, than previously thought
More: http://www.space.com/scienceastronomy/090304-pluto-atmosphere.html (http://www.space.com/scienceastronomy/090304-pluto-atmosphere.html)
The icy dwarf planet Pluto undergoes dramatic seasonal changes, according to images from the Hubble Space Telescope.
The pictures from Hubble revealed changes in the brightness and the colour of Pluto's surface.
Mike Brown, from the California Institute of Technology, suggested Pluto had the most dynamic surface of any object in the Solar System.
MORE...... http://news.bbc.co.uk/1/hi/sci/tech/8498455.stm
Hubble Discovers a Fifth Moon Orbiting Pluto
A team of astronomers using NASA's Hubble Space Telescope is reporting the discovery of another moon orbiting the icy dwarf planet Pluto.
The moon is estimated to be irregular in shape and 6 to 15 miles across. It is in a 58,000-mile-diameter circular orbit around Pluto that is assumed to be co-planar with the other satellites in the system.
"The moons form a series of neatly nested orbits, a bit like Russian dolls," said team lead Mark Showalter of the SETI Institute in Mountain View, Calif.
The discovery increases the number of known moons orbiting Pluto to five.
More: http://hubblesite.org/newscenter/archive/releases/2012/32/full/
The International Astronomical Union (IAU) is announcing that the names Kerberos and Styx have officially been recognised for the fourth and fifth moons of Pluto, which were discovered in 2011 and 2012. The names were submitted to the IAU by the leader of the team responsible for the discovery, who had called for the help of the general public in an open contest that attracted a substantial number of participants.
The IAU is pleased to announce that today it has officially recognised the names Kerberos and Styx for the fourth and fifth moons of Pluto respectively (formerly known as P4 and P5). These names were backed by voters in a recently held popular contest, aimed at allowing the public to suggest names for the two recently discovered moons of the most famous dwarf planet in the Solar System.
The new moons were discovered in 2011 and 2012, during observations of the Pluto system made with the NASA/ESA Hubble Space Telescope Wide Field Camera 3, and increasing the number of known Pluto moons to five. Kerberos lies between the orbits of Nix and Hydra, two bigger moons discovered by Hubble in 2005, and Styx lies between Charon, the innermost and biggest moon, and Nix. Both have circular orbits assumed to be in the plane of the other satellites in the system. Kerberos has an estimated diameter of 13 to 34 kilometres, and Styx is thought to be irregular in shape and is 10 to 25 kilometres across.
MORE (http://www.iau.org/public_press/news/detail/iau1303/)
should have called one Vulcan...
Vulcan Loses In Pluto Moons Name Game. Did the IAU Choose Wisely?
It looks like Vulcan was not the logical choice for the International Astronomical Union when it came to naming Pluto's new moons.
The internationally recognized body for astronomy names selected Kerberos and Styx as the new names for Plutonian moons P4 and P5, respectively. While these names were popular in a public vote last year concerning Pluto's new moons, Vulcan — the overwhelming favorite, and backed by none other than Star Trek's Captain Kirk (William Shatner) — was not selected.
More: http://www.universetoday.com/103241/vulcan-loses-out-in-pluto-moon-name-game/
...and an APOD: http://apod.nasa.gov/apod/ap130708.html
SwRI study finds that Pluto satellites' orbital ballet may hint of long-ago collisions
A large impact 4 billion years ago may account for the puzzling orbital configuration among Pluto's five known satellites, according to a new model developed by planetary scientists from Southwest Research Institute (SwRI).
Starting with Charon, Pluto's nearest and largest moon, each of the successively more distant — and much smaller — moons orbits Pluto according to a steadily increasing factor of Charon's own orbital period. The small satellites, Styx, Nix, Kereberos and Hydra, have orbital periods that are almost exactly 3, 4, 5 and 6 times longer than Charon's.
"Their distance from Pluto and the orbital arrangement of the satellites has been a challenge for theories of the small satellites' formation," said lead investigator Dr. Harold "Hal" Levison, an Institute scientist in SwRI's Planetary Science Directorate at Boulder, Colo.
Models for the formation of Charon leave plenty of small satellites, but all of them are much closer to Pluto than the current system that we see today," said Levison. A major problem has been understanding how to move these satellites outward, but not lose them from the Pluto-Charon system or have them crash into Charon. He said, "This configuration suggests that we have been missing some important mechanism to transport material around in this system."
More: http://www.swri.org/9what/releases/2013/pluto-moon.htm
Hubble Finds Pluto's Moons Tumbling in Absolute Chaos
If you lived on one of Pluto's moons, you might have a hard time determining when, or from which direction, the sun will rise each day. Comprehensive analysis of data from NASA's Hubble Space Telescope shows that two of Pluto's moons, Nix and Hydra, wobble unpredictably.
"Hubble has provided a new view of Pluto and its moons revealing a cosmic dance with a chaotic rhythm," said John Grunsfeld, associate administrator of NASA's Science Mission Directorate in Washington. "When the New Horizons spacecraft flies through the Pluto system in July we'll get a chance to see what these moons look like up close and personal."
More from NASA (http://www.nasa.gov/press-release/nasa-s-hubble-finds-pluto-s-moons-tumbling-in-absolute-chaos)