Comets and asteroids preserve the building blocks of our solar system and should help explain its origin. But there are unsolved puzzles. For example, how did icy comets obtain particles that formed ...

Astronomers say they have figured out the true chemical makeup of our solar system, revealing that it contained much more carbon, oxygen and nitrogen than previously thought. Chiefly, the finding ...

Shortly after discovering the law of gravity, Isaac Newton wondered whether it would allow our Solar System to remain stable. At face value, the problem seems trivial. The gravitational perturbations ...

About 4.5 million years ago, a great cosmic dog kicked past our Solar System – and its effects may still be seen today.

This close-up view of comet Hartley 2 was taken by NASA's EPOXI mission during its flyby of the comet on November 4, 2010,and was captured by the spacecraft's Medium-Resolution Instrument. Image ...

Over short time scales, the solar system is a beautifully predictable dance, with each planet behaving in a ways that astronomers can calculate — but over long enough periods, it's not such an orderly ...

"We have been calling Uranus an ice giant, but we don't really know its nature." When you purchase through links on our site, we may earn an affiliate commission. Here’s how it works. Astronomers say ...

Washington, D.C.— Comets and asteroids preserve the building blocks of our Solar System and should help explain its origin. But there are unsolved puzzles. For example, how did icy comets obtain ...