The enormous visitor to our solar system may have been about 8 times the mass of Jupiter, and come nearly as close to the sun ...

"Chemical rockets that we use today, even with the extra speed boost from flying by planets, or from swinging by the sun for ...

An object eight times the mass of Jupiter may have swooped around the sun, coming superclose to Mars' present-day orbit ...

Scientists suggest an interstellar visitor may have altered planetary orbits in our Solar System, reshaping trajectories of ...

The research, yet to be peer-reviewed, sheds light on what could have changed the orbits of several planets in the solar ...

While an antimatter engine is very far off, researching it could yield other discoveries as well.

A new study suggests that a planet-sized object may have passed through the solar system billions of years ago.

An interstellar visitor To tackle this puzzle, Malhotra and colleagues considered a less-examined scenario: that a visiting star-size object tweaked these planets' paths around 4 billion years ago.