The invention of the telescope in the 17th century provided scientists with unprecedented, yet hazy, images of Mars. Some observers saw canals; others saw diagrams drawn for "interplanetary communication."

For all their similarities, Mars possesses unique geophysical traits — traits that early on set Mars on a developmental path distinct from Earth's.

Mercury is the most unusual of the four planets closest to the Sun. It’s also the most neglected. Until MESSENGER, it was the only one of the four that hadn’t been comprehensively imaged.

Discover how scientists are now marrying traditional fieldwork with cutting-edge computer modeling to produce the first animated, theoretical picture of the Basin and Range Province's geological evolution.

In 2004, news of Asteroid MN4 hit the blogosphere: "So, in summary, there's a 1-in-233 chance of the worst disaster in recorded history happening on April 13, 2029, and a 232-in-233 chance of nothing happening." Take a closer, scientific look.

Given the potential for asteroids to literally and figuratively impact life on Earth in a profound way, asteroids have been quite sought after since the first and largest one, Ceres, was discovered in 1801. Learn more.

Meteorite specialist Dr. Denton Ebel talks asteroids bigger than Everest, glass mini-marbles raining from the sky, and dinosaur toast.

The Sloan Telescope has a digital camera the size of a dishwasher that’s sophisticated enough to capture every luminous object in the northern celestial hemisphere. Take a closer look.

Have you ever stumbled upon a discovery while looking for something completely different? See what surprises astronomers found as part of the Sloan Digital Sky Survey.

What is the Universe’s arrangement today? What did it look like at its birth? And how did we get from then to now? These are just some of the “Big Questions” astronomers are making headway answering.