Turn a telescope to the eastern sky in the hours following midnight on Nov. 5 to see two colossal shadows darken the cloud tops of the gas giant Jupiter as the Galilean moons Io and Europa pass between the colossal world and the sun.
Jupiter will be visible as a bright point of light roughly 30 degrees high in the eastern sky at 12:13 a.m. EST (0513 GMT) on Nov. 5. During this time, the shadows of both moons will be visible darkening the Jovian disk as it shines below the bright "twin" stars Castor and Pollux in the constellation Gemini. Remember, the width of your clenched fist held at arm's length is roughly equivalent to 10 degrees in the night sky.
