LISA Pathfinder - forerunner of a mission that, it is hoped, will detect gravitational waves from space - lifted off at 4:04 GMT (12:04 a.m. EST) on on December 3, 2015.
An analysis of the cosmic microwave background revealed bright spots, possible imprints left when an alternate universe bumped ours shortly after the Big Bang.
Theoretical calculations by a JPL astronomer suggest that streams of dark matter - passing through Earth - would emerge as ultra-dense filaments or "hairs."
Mars’ large moon Phobos is slowly falling toward the planet. In 20-40 million years, it'll shatter, and its pieces will form a Saturn-like ring around Mars.
Jupiter's gravity slings long-period comets out of harm's way, while nudging some asteroids closer to Earth. And, in 1770, Jupiter took aim on Earth - but missed.