A planet-size object that possibly once visited the solar system may have permanently changed our cosmic neighborhood by warping the orbits of the four outer planets, a new study suggests.

Space is all around us. We live on planet Earth but there are loads more planets up in space. There are also stars and moons. The closest star to Earth is the Sun. In our solar system there are 8 ...

Shimpei Yamashita via Getty Images The night sky will offer stargazers a special sight for the next several weeks: Right now, all ... if the planets actually aligned with each other in space ...