The Cassini spacecraft snapped this shot in February as it swooped past Calypso, which trails behind the larger moon Tethys in roughly the same orbit around Saturn.
Equally puzzling are observations of the same boundary region with an instrument on the Cassini spacecraft, which recorded the density of atoms at higher energies, above 6,000 electron volts.
On the basis of these experiments and of field observations, the so-called law of competitive exclusion was formulated, according to which no two species can occupy the same niche.
Studio heads realized that they couldn't make virtually the same film over and over again with the same cast of stars and still expect to keep turning a profit.
Finally, this raises the question — prior to 2010, when was the last time that we had a total lunar eclipse occur on the same calendar date as the winter solstice?