June 22, 2005: Stick up your thumb and hold it at arm's length. It doesn't seem very big, does it? But it is, big enough to hide three planets. This weekend Mercury, Venus and Saturn are going to crowd together in a patch of sky no bigger than your thumb. Astronomers call it a "conjunction" and it's going to be spectacular.

The show begins on Saturday evening, June 25th. Step outside and look west toward the glow of the setting sun. Venus appears first, a bright point of light not far above the horizon. As the sky darkens, Saturn and Mercury pop into view. The three planets form a eye-catching triangle about 1.5o long, easily hidden by your thumb.


gets better on Sunday evening, June 26th. The triangle shrinks with Venus and Mercury only 0.5o apart. Now they fit behind your pinky!
Monday evening, June 27th, is best of all. With Saturn nearby, Venus and Mercury converge. At closest approach, the two planets will be less than one-tenth of a degree apart. Such pairings of bright planets are literally spellbinding.


http://science.nasa.gov/headlines/y2...htm?list179029