In 2009, a pair of astronomers at the Paris Observatory announced a startling discovery. After building a detailed computational model of our solar system, they ran thousands of numerical simulations, ...

A new study suggests that a close encounter with a massive interstellar object, possibly eight times the mass of Jupiter, may have significantly altered the orbits of the four outer planets in our ...

For the inner four planets in this solar system, each planet orbits the sun three times for every two orbits of the planet immediately to its outside. For the fourth, fifth and sixth planets, they ...