Nasa's Interstellar Boundary Explorer (Ibex) spacecraft has been launched
into Earth orbit to study the edge of our Solar System.
Ibex was launched on Sunday aboard a Pegasus rocket that was dropped from a
jet flying over the Pacific Ocean.
It is the first probe to study particle interactions at the boundary where
our Solar System meets interstellar space.
The two-year mission should shed light on the decline of the solar wind,
which is at its lowest pressure in 50 years.
The interstellar bounda
