In the time Pluto was found, classified as a planet and reclassified as a dwarf planet, it has not completed one orbit. One ...

There may be an undiscovered planet in the outer solar system whose presence is revealed by the strange orbit of objects beyond the eighth planet Neptune. The tantalizing prospect of a ninth ...

3 min read Solar energy is the technology used to harness the sun's energy and make it useable. As of 2011, the technology produced less than one tenth of one percent of global energy demand.