Sinuous valley networks like these imaged by Viking 1 led many planetary scientists to think Mars’ climate once was warm and wet, but some researchers aren’t so sure. NASA/JPL Today marked the 114th consecutive day in Orlando in which the temperature never dipped below 70°. I'm currently sweating...

If you've been watching the Moon after sunset this week, you may have noticed it lies lower in the sky than usual (at least if you live at mid-northern latitudes). It's not your imagination — the Moon is figuratively scraping the treetops this week. Although this is no great mystery, it never...

Phoenix's robotic arm digs a trench in the ice-rich martian soil, seeking signs as to whether Mars may be hospitable to life. Corby Waste (JPL) If the weather holds along Florida's Atlantic coast, NASA's Phoenix spacecraft should blast off from Cape Canaveral this Saturday. Its target: the...

On January 14, NASA’s MESSENGER spacecraft will fly past Mercury. MESSENGER — short for MErcury Surface, Space ENvironment, GEochemistry, and Ranging — will be making the first close-up observations of the innermost planet in 33 years. This flyby marks the first of three encounters with the planet, providing...

On January 14, NASA’s MESSENGER spacecraft flies past Mercury. MESSENGER — short for MErcury Surface, Space ENvironment, GEochemistry, and Ranging — will be making the first close-up observations of the innermost planet in 33 years. This flyby marks the first of three encounters with the planet, providing...

On January 14, NASA’s MESSENGER spacecraft flew past Mercury. MESSENGER — short for MErcury Surface, Space ENvironment, GEochemistry, and Ranging — made the first close-up observations of the innermost planet in 33 years. This flyby marked the first of three encounters with the planet, providing gravity...

On January 14, NASA’s MESSENGER spacecraft flew past Mercury. MESSENGER — short for MErcury Surface, Space ENvironment, GEochemistry, and Ranging made the first close-up observations of the innermost planet in 33 years. This flyby marked the first of three encounters with the planet, providing gravity...

On January 14, NASA’s MESSENGER spacecraft flew past Mercury. MESSENGER — short for MErcury Surface, Space ENvironment, GEochemistry, and Ranging — made the first close-up observations of the innermost planet in 33 years. This flyby marked the first of three encounters with the planet, providing gravity...

On November 7, Japan’s SELENE spacecraft captured this high-definition image of Earth rising over the Moon’s north pole. JAXA/NHK If prime-time television, National Geographic specials, and sports programming don’t get you pumped for seeing TV at the highest-possible resolution, then what else is there...

It seems to me that Saturn’s moon Rhea is a leading candidate for Rodney Dangerfield of the solar system. I tell you, it doesn’t get much respect. Even in the Saturn system, where Rhea is the second-largest moon, it ranks pretty low. You hear about Titan, with its thick atmosphere and methane lakes....