Feburary, 2003

Io Transit on 12 Jan.

Io (3630 km in diameter) which is slightly larger than the Earth's moon. To the right of Io is a dark spot that is Io's own shadow. The dark polar region of Io has been visually reported by observers in last 100 years and some sketches had been done by experienced observer before. Io usually appears as an oval shape as the dark polar regions merge against the dark sky background.

A more amazing Io tranit photo can be retrieved from Astronomy Picture of the Day on Dec 07, which shows the high resolution Io transit scene captured by the Cassini Spacecraft while it was flying by the Jupiter on Dec 2000.