The Voyager I spacecraft, 33 years into its mission, "has outrun the solar wind" and is exiting the solar system. This nice article explains what this means, and has a bunch of wonderful details and interviews with the original mission scientists. [more inside]
Where did Venus’s water go? Water may have once been as abundant on Venus as it is on Earth. New data from the Venus Express suggests that the planet's lack of a magnetic field has allowed water in the atmosphere to be stripped apart and carried into space by the solar wind.