On Tuesday evening, April 8, you can experience one of the most beautiful events the sky can deliver. Head outside no later than an hour or so after sunset (around 8:30 P.M. local daylight time) and look to the west. Your eyes should land immediately on the slender crescent Moon, oriented with its cusps standing nearly straight up from the horizon. Point your binoculars at the Moon to reveal a stunning sight: the bright Pleiades star cluster (M45...

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. Enceladus is known for its liquid-water geysers and Iapetus for its strange black and white hemispheres. Even tiny Mimas, with its cute “Death Star” crater...

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? Television may not be the “vast wasteland” it once was claimed to be, but you could make a good case that seeing incredible detail in TV’s moving...

“Slow down, you move too fast.” Paul Simon wrote those lyrics to open “The 59th Street Bridge Song,” from Simon and Garfunkel’s classic 1966 album Parsley, Sage, Rosemary & Thyme . As the title suggests, Simon was referring to what New Yorkers’ know better as the Queensboro Bridge. But he could just as easily have been feelin’ groovy about how our calendar runs faster than Earth’s revolution around the Sun. Today — February 29 — marks the day...

Among life’s many mysteries, the answer to the question above has to rank pretty low. Higher on my list: Why are woodchucks also called groundhogs? After all, wood and ground are hardly synonymous, and a “chuck” has nothing to do with a “hog.” But the biggest question about woodchucks and groundhogs has to be why these furry rodents became associated with weather forecasting. Tomorrow is Groundhog Day, and tradition holds that if the groundhog sticks...

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 assists necessary to place the probe in orbit around Mercury in March 2011. January 25, 2008 As Mercury fades in the distance, MESSENGER continues...

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 assists necessary to place the probe in orbit around Mercury in March 2011. January 16, 2008 The first close-up images of Mercury have made their way...

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 assists necessary to place the probe in orbit around Mercury in March 2011. January 15, 2008 It’s okay to exhale. Everyone involved with the MESSENGER...

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 gravity assists necessary to place the probe in orbit around Mercury in March 2011. January 14, 2008 This afternoon, NASA’s MESSENGER spacecraft...

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 gravity assists necessary to place the probe in orbit around Mercury in March 2011. January 11, 2008 This morning, NASA’s MESSENGER spacecraft...