MELISSA BLOCK, host:
Those rovers are only two of six spacecraft either on the surface of Mars or in orbit around it and Mars is only one of many planets with mechanical visitors from Earth right now.
Commentator Kelly Beatty is executive editor of Sky and Telescope magazine. He says that space exploration in 2006 is more exciting than it's ever been.
KELLY BEATTY reporting:
For anyone coming of age in the 1960s as I did, space exploration was pretty much all about the race to the moon. The U.S. and Soviet Union slugging it out for bragging rights.
Who'd be the first to crash into the moon? The first to orbit it? And of course the first to set foot on its surface? In the end we won by what turned out to be a landslide.
But back then the planets were still distant and almost completely unknown. Even at the tender age of 12, when I peered at small peach colored Mars through my backyard telescope, I was free to imagine what it'd be like to stand on its wind-swept plains.
I wondered whether I could float in the dense clouds of Jupiter. Would sunlight still feel warm from as far away as Pluto? I didn't have the answers, but then neither did astronomers and I figured that my guesses probably weren't much crazier than theirs. But soon we stopped guessing. In just a fraction of a lifetime, spacecraft dispatched from planet Earth traveled the depth and breadth of the sun's realm.
As the late Carl Sagan liked to say, ours is the only generation in human history to explore the solar system for the first time. Never before has interplanetary space bristled with so much activity. Spacecraft are on their way to Mercury, Jupiter, Pluto and a comet. NASA's CUSeeme has been circling Saturn for nearly two years. The Japanese recently scored a touchdown on an asteroid and a European craft is orbiting the moon.
Last July 4th we attacked one comet then a capsule landed in Utah with samples from another. Whew! I follow this stuff for a living and my brain, like NASA's tracking system, is completely topped out.
Frankly, part of me wishes that we didn't know so much about the solar system. When I head outside to observe a planet, I still want it to be a little mysterious. Then again I'm equally glad that we live in such enlightened times. Now I know that Mars looks red because its rocks are, well, rusty.
Nowadays gazing at nearby worlds through my telescope offers the double joy of knowing them and imagining them in the same satisfying glimpse.
BLOCK: Kelly Beatty is executive editor of Sky and Telescope magazine. Transcript provided by NPR, Copyright NPR.