Our Sun May Have Been Born With a Trouble-Making Twin Called ‘Nemesis’

A recent model on how stars are formed adds weight to the hypothesis that most – if not all – stars are born in a litter with at least one sibling. Our own star at the center of the Solar System is probably no exception, and some astronomers suspect that the Sun’s estranged twin might … Read more

Scientists Say We Should Rethink Moons as Planets… And Reinstate Pluto

The International Astronomical Union (IAU) has a very strict definition of the word “planet”. According to the definition – drafted, tweaked, and agreed upon in August 2006 – an astronomical body is officially a planet if it orbits the Sun, has sufficient mass to be spherical, and has cleared the neighborhood around its orbit.   … Read more