For decades, we believed our Solar System ended with Neptune, followed only by icy debris and distant dwarf planets. But recent observations hint that something much larger could be lurking in the darkness beyond everything we know.

How did the first solids that made up planets, moons and asteroids form from the "hot soup" that characterized our solar system's earliest years? New research from Caltech analyzing pieces of a meteorite has found that,

Oh, we humans do love a cleanly defined boundary, don’t we? They make things easier, after all. If we’re trying to categorize something, knowing what labeled bin to put it in is handy. If we’re looking for trends, then sharp boundaries are even ...

This is HOPS-315, a baby star where astronomers have observed evidence for the earliest stages of planet formation. The image was taken with the Atacama Large Millimeter/submillimeter Array (ALMA). In a groundbreaking observation, astronomers have detected ...

And the earth was without form and void, and darkness was upon the face of the deep. Sometimes, if the night is dark and clear enough, you can look up and see the Milky Way in its arc across the sky. That's our galaxy, and so are most of the other stars ...

Spiral Galaxy from Kirkland et al. CREDIT Chris Kirkland and colleagues. A new study of zircon crystals from two of Earth’s oldest continents indicates that the formation of Earth’s continental crust goes through cycles, with periods of increased crust ...

Forbes contributors publish independent expert analyses and insights. An award-winning reporter writing about stargazing and the night sky. An object has been discovered orbiting the sun far beyond Pluto, calling into question theories about a possible ...

Our solar system is a smashing success. A new study suggests that from its earliest period — even before the last of its nebular gas had been consumed — Earth’s solar system and its planets looked more like a bin of well-used LEGO blocks than slowly ...

Add Yahoo as a preferred source to see more of our stories on Google. Are planets in the solar system that are closer to the Sun older than the ones further away? – Gavriel, age 10, Paducah, Kentucky A cloud of collapsing gas created our Sun, the first ...

A distant 'exomoon' the size of Jupiter is changing how we think about the cosmos.

Based on the composition of gases spewed by the icy space rock, researchers estimate that our guest might be up to 12 billion years old—about three times the age of the solar system