These two recent discoveries show that the Pluto system is more crowded than scientists had thought.

MSN: New Pluto moon hints at perilous journey for spacecraft

Stern and his colleagues are inventorying the Pluto system with Hubble to get a better handle on the risks New Horizons faces, and to help design the safest possible trajectory for the spacecraft.

MSN: New Pluto moon hints at perilous journey for spacecraft

And water would be all the more exciting on Ganymede because it is the largest moon in the solar system (larger even than the planets Mercury and Pluto) and, like earth, it has a permanent magnetic field that protects part of its surface from bombardment by certain sorts of life-destroying radiation.

ECONOMIST: Blue moon

This periodic reappearance of fresh frost takes place every Pluto-year (248 Earth-years) and is the reason that Pluto is one of the most reflective surfaces in the Solar System.

BBC: Scientists plan Pluto flyby

But most of the history of the solar system--this is why the comet is so important--most of the history of this comet was spent out beyond Neptune, out where Pluto is at the very edge of the solar system, what we call the Kuiper belt.

NPR: Stardust Set to Deliver Comet Samples

But first, we haven't heard the last about the ignominious vote last month to strip Pluto of its place in our solar system - kicked out of the planetary lineup by a group of astronomers because it doesn't fit the new definition of what a planet is.

NPR: Astronomers Prepare to Fight Pluto Demotion

But part of the problem with the definition - I mean, as an example - is that if you look at Mars - if Mars - if we discovered a Mars-sized object out beyond the orbit of Pluto, it couldn't be a planet, because over the age of the solar system it wouldn't have time to clear its orbit.

NPR: Astronomers Prepare to Fight Pluto Demotion

The "new" Solar System agreed at the IAU's General Assembly has eight planets - Mercury to Neptune - and at least three dwarf planets: Pluto, Eris and the largest asteroid in the Solar System, Ceres.

BBC: NEWS | Science/Nature | Astronomers name 'world of chaos'

At a time when rovers are exploring Mars, a satellite is looping around Saturn's rings and a body larger than Pluto was recently found in the far reaches of the solar system, the reader who wants to catch up on developments could have done with a book of more uniform quality.

ECONOMIST: Twirls and swirls from outer space

The suburbs of the solar system are filled with small, icy objects, including Pluto.

NPR: Pluto, the Un-Planet?