Jangler

NEW HORIZONS: The New Horizons probe, launched by NASA in 2006, is on its way to humankind's first close-up encounter with Pluto. To reach its distant destination, New Horizons left Earth at blinding speed, passing lunar distance in about nine hours and reaching Jupiter in just over a year. The probe should reach Pluto in 2015, and then may head into deeper reaches of the solar system, investigating the Kuiper Belt, the icy debris field where Pluto resides.

MESSENGER: The Mercury Surface, Space Environment, Geochemistry and Ranging (MESSENGER) craft took flight five years ago and in 2011 will become the first probe to orbit Mercury. The closest planet to the sun, Mercury is difficult to study from Earth, and before the first of MESSENGER's flybys of the planet, less than half of its surface had even been photographed. Those flybys are already providing clues to some of Mercury's mysteries by measuring the planet's magnetic field, assessing its chemical composition, and mapping its pockmarked surface in three dimensions.