Supercomputer simulations of galaxies show that Einstein’s general theory of relativity might not be the only way to explain how gravity works or how galaxies form. Read more.
Binoculars or a small telescope would reveal Jupiter's 4 major moons, called Io, Europa, Ganymede and Callisto. They're all as big or bigger than Earth's moon. Find out the present positions of Jupiter's 4 big moons, and read more.