Over the past decade, researchers have been puzzling through Pluto’s mysteries. Meanwhile, the New Horizons probe heads for interstellar space.

On July 4, there will be an uncommonly good opportunity to get a glimpse of Mercury, the smallest, speediest planet in our solar system. Named after the Roman god known for his winged feet and ...

Republicans want to add work requirements for Americans to get Medicaid. Is that a necessary step to fight "waste, fraud, and abuse" or a sneaky way of cutting the social safety net?