Science teams from across the United States have submitted 28 proposals for missions to explore the moons of Jupiter and Saturn, touch the asteroid-like satellites orbiting Mars, visit unseen worlds and hunt for objects that could strike Earth one day.

The Rosetta spacecraft neared its comet Saturday, targeting a close flyby within six kilometres of the tiny world’s jagged nucleus to gain new up-close views of the comet and taste the growing vaporous cloud surrounding it.

A concept called Comet Hitchhiker, developed at NASA’s Jet Propulsion Laboratory, puts forth a new way to get into orbit and land on comets and asteroids, using the kinetic energy — the energy of motion — of these small bodies. Masahiro Ono, the principal investigator based at JPL, had Douglas Adams’ “Hitchhiker’s Guide to the Galaxy” in mind when dreaming up the idea.