Earth, Mars, Jupiter, and Saturn: Highlights from the last decade of space photography
We began haltingly, with rockets that scraped the edge of space with their noses; moved on to orbiters that circled us in our small, atmospheric cocoon; and, gradually, we grew more confident, sending not just probes and dogs and monkeys, but our own flesh and blood to the moon.
Today, we have humans living on a semi-permanent basis in space, rovers prowling about Mars, and spacecraft whizzing by planets beyond the asteroid belt. Voyager I, our farthest-sailing creation yet, will soon leave the bubble of our sun's winds and cross into interstellar space -- a boundary we've only begun to understand in the 35 years since Voyager launched. We haven't exactly conquered the solar system, but we have laid our claim.
At the same time, we are getting a better idea of just what a tiny speck in the universe our solar system is. Our telescopes both in orbit and on the ground have provided us with ever-clearer pictures of the universe beyond our solar neighborhood: nearby stars, local galaxies, and the deepest reaches of the universe. In 1995, scientists aimed the Hubble telescope at a tiny, blank patch of the night sky; they found it teeming with *galaxies*. NASA's Kepler mission has identified thousands of probable planets orbiting stars just in the local region of the Milky Way. Just two decades ago, we didn't know there was a single one. Last week, we learned there is at least one planet orbiting Alpha Centauri B, located in the system of stars closest to our own.