In a sky as clear as any on Earth, the stars over southeastern Australia's Lake Benanee begin to turn on their lights even before the last beams of sunlight disappear behind the western horizon.  The bright star in the lower center, whose light is reflected by the glassy sheen of the lake, is the nearest star system to our sun—Alpha Centauri—"only" 26 trillion miles, or 4.3 light years distant.