With this new survey, astronomers have gained a peek inside a stage of exoplanet system formation they have yet to fully ...

Mike Brown is convinced that beyond Neptune, at the far reaches of our solar system, there's an unseen giant planet. "This is the 5th largest planet in our solar system, lurking out there, waiting to ...

Our planet whirls around the sun in an ellipse, rather than a circle. On Thursday the planet reached its farthest point from its star, known as aphelion. By Katrina Miller This article was originally ...

Since the 1990s, scientists have discovered approximately 6,100 planets outside our solar system, called exoplanets.