It Would Take About 100 Billion Years for Another Star to Pass Close Enough to Make the Solar System Unstable

In 1687, Sir Isaac Newton published his magnum opus, PhilosophiƦ Naturalis Principia Mathematica, which effectively synthesized his theories on motion, velocity, and universal gravitation. In terms of the latter, Newton offered a means for calculating the force of gravity and predicting the orbits of the planets. Since then, astronomers have discovered that the Solar System … Read more

Pluto’s Orbit is Surprisingly Unstable

In 1930, astronomer Clyde Tombaugh discovered the fabled “Ninth Planet” (or “Planet X”) while working at the Lowell Observatory in Flagstaff, Arizona. The existence of this body had been previously predicted based on perturbations in the orbit of Uranus and Neptune. After receiving more than 1,000 suggestions from around the world, and a debate among … Read more