Neptune, one of our most distant planetary neighbors, may not be the color we've always thought it was. Previous images of far-off planets showed Neptune as being a deep electric blue, while ...

For the first time in history, we now have real, high-resolution images of Neptune that go beyond artist impressions and telescope visuals. Captured by advanced space telescopes and spacecraft ...

The hypothetical Planet Nine is imagined as an ice giant in this artist’s conception. Neptune’s orbit is shown as the ellipse around the distant Sun (upper right).

Our Solar System, a sprawling collection of planets, moons, asteroids, and comets bound together by the Sun’s gravity, has long been thought to hold hidden secrets beyond Neptune. Planet Nine ...

Astronomers have always felt uncertain about Pluto, the outermost planet in the solar system. It is suspiciously small, with less than half of the earth's diameter, and its orbit is peculiar.

Neptune and Uranus, ... These experiments give scientists strong evidence that the wild idea of diamonds falling from the skies on icy planets might actually be real. 6 / 6.

If Planet Nine is real, “my instant reaction might be relief,” Brown says. He admits that should he not be the one to first cast eyes on it, he would feel an initial gut punch of frustration ...