Science Agenda: To the Moons, NASA; July 2012; Scientific American Magazine; by The Editors; 1 Page(s)

Last year, after a lengthy, circuitous journey through the solar system, a NASA probe known as MESSENGER entered into orbit around Mercury. No spacecraft had visited the innermost planet in more than three decades, and none has paid an extended visit. With MESSENGER's arrival, NASA and its international counterparts now have spacecraft stationed at Mercury, Venus, Mars and Saturn—not to mention Earth and the moon. Two more NASA craft are en route to Jupiter and Pluto; yet another ought to reach the dwarf planet Ceres in 2015. Humankind's presence has never stretched so far.

It could stretch farther still, with robots spying down on bizarre moons that might harbor alien life or on the little-understood outermost planets. An even more novel campaign would ferry Martian rocks back to Earth for analysis. NASA had been on track to begin such an ambitious project, but alas, political maneuvering recently forced the space agency to scrap its plans.