A Double Shadow on Jupiter

A Double Shadow on Jupiter

via One-Minute Astronomer de admin em 24/08/09

As August moves into its final days, Jupiter, the King of Planets, wheels into view late in the evening and promises to put on many fine shows over the coming months. This week, you'll have a chance to see a rare double shadow on the face of Jupiter cast by the moons Europa and Ganymede.

The shadows come into view from 10:20 p.m. on August 26 to 1:12 p.m. August 27 (that's 2:20 to 5:12 Universal Time on August 27).

To see the double shadow, you'll need access to at least a 3-4″ telescope capable of magnifying 100-150x. The face of Jupiter right now is a respectable 48 arc-seconds across, but the moon shadows will look like tiny pin-pricks of darkness. So look carefully… this will not be easy to see. But with a little patience and steady sky, you'll get to glimpse this unusual sight.

Here's an example of a single shadow across Jupiter… this is real photography, but your view visually through a telescope won't be this clear. Still, it gives you an idea of what to look for.

The biggest planet rises in the east after sunset and climbs into the southeastern sky by midnight. It's the brightest object in that part of the sky, shining at an impressive magnitude -2.9.

If the sky is clear tomorrow night, give it a try!