The Glitter of Distant Seas

摘要

In Star Wars, a gas giant's jungle moon, Yavin 4, drifts inexorably into the pow-erful beam of the Death Star. This scene closely mirrors a recent development in radar astronomy. Planetary alignments now expose Saturn's giant, haze-shrouded moon Titan to the recently upgraded 300-m Arecibo radar dish. Campbell et al. have used this dish to blast Titan with hundreds of kilowatts of microwave power. As they report on page 431 of this issue, 2 hours later they received a faint echo at the rebuilt 100-m Green Bank radio telescope. Because the results have a much higher signal-to-noise ratio than previous efforts with smaller dishes, they carry much more information. The results confirm that Titan is like nowhere else in the solar system.