Back in 1995, astronomers had detected a planet orbiting around a Sun-like star. This was a huge deal. And today, we have discovered more than 4000 extrasolar planets. They come in a wide variety of sizes and characteristics. By the most optimistic projections, only about 50 are habitable, and only 20 have Earth-like temperatures. So, if we were to send off a probe to explore some of these worlds, what would be the top 5 nearest choices to visit?
Irene W. Pennington Planetarium 