Over 100 Planet Solar System?

Pluto’s status as a non-planet may be coming to an end. Professor Mike Brown of Caltech ended Pluto’s planetary status in 2006. But now, Kirby Runyon, a doctoral student at Johns Hopkins University, thinks it’s time to cancel that demotion and restore it as our Solar System’s ninth planet. Pluto’s rebirth as a planet is…

Cycles of the Galactic Plane

How often does the Sun pass through a spiral arm in the Milky Way? Knowing that our solar system does not just stay in one place as it revolves around the center of the galaxy, how long will it take for our solar system to move out of the spiral arm it is currently in…