A nice op-ed piece by Timothy Ferris in New York Times: The Mix Tape of the Gods
Thirty years ago today, the Voyager 1 space probe — a one-ton robotic craft whose long antennas make it look rather like a spider the size of a school bus — was launched from Cape Canaveral, Fla., on a mission to reconnoiter Jupiter and Saturn. To succeed, Voyager would have to survive five years in the vacuum of space, where it would encounter cosmic rays, solar flares, the hurtling rocks and sand of the asteroid belt, and Jupiter’s intense radiation bands.
The probe did all that, transmitting back reams of scientific data and memorable color photos: of the sputtering red and yellow volcanoes of Jupiter’s moon Io; of the shimmering blue ice that shrouds Io’s fellow satellite Europa, beneath which a liquid ocean is suspected to dwell; of Saturn’s myriad rings and the murky mysteries of its orange satellite, Titan, whose hazy atmosphere is thought to approximate that of the early Earth.
Having accomplished its mission, Voyager 1 might have quietly retired. Instead it remains active to this day, faithfully calling home from nearly 10 billion miles away — so great a distance that its radio signals, traveling at the speed of light, take more than 14 hours to reach Earth. From Voyager’s perch, the Sun is just another star, south of Rigel in the constellation Orion, and the Sun’s planets have faded to invisibility.
Its twin, Voyager 2, explored all the outer planets (we can now say "all" after the sad demotion of Pluto - no no, I'm not upset about it at all :o) ) and is also reaching the edge of our solar system:
That limit is defined by a teardrop-shaped bubble called the heliosphere, where the solar wind (particles blown off the Sun’s outer atmosphere) comes to a halt.
If all continues to go well, Voyager should pierce the heliosphere’s outer skin by around 2015. It will then depart into the void of interstellar space, where it is destined to wander among the stars forever.
This is truly awesome:
Forty thousand years will elapse before Voyager 1, departing the realm of the Sun at a speed of 38,000 miles per hour, passes anywhere near another star. (It will drift within 1.7 light years of a dim bulb called AC+79 3888.) And 358,000 years will elapse before Voyager 2 approaches the bright star Sirius.
Out there, our concepts of velocity become provincial. The stars are moving, too, in gigantic orbits around the center of the Milky Way galaxy. Voyager, a toy boat on this dark sea, will not so much approach Sirius as watch it sail by, bobbing in its mighty wake.
Contemplation of Voyager’s billion-year future among the stars may make us feel small and the span of our history seem insignificant. Yet the very existence of the two spacecraft and the gold records they carry suggests that there is something in the human spirit able to confront vast sweeps of space and time that we can only dimly comprehend.
If some recoil from the brink of space, others find it liberating. Our perspective was aptly expressed by the 18th-century science writer Bernard de Fontenelle, in his fictional dialogue “A Plurality of Worlds.” “You have made the universe so large that I know not where I am, or what will become of me,” complains a lovely young marquise whom Fontenelle is tutoring. “I protest it is dreadful.”
“Dreadful, Madam?” Fontenelle replies. “For my part, I am very easy about it.