Had Jupiter continued to gain weight, it would have grown ever hotter and hotter, and ultimately self-sustaining, raging nuclear-fusing fires may have been ignited in its heart. This would have sent Jupiter down that long, shining stellar road to full-fledged stardom. Had this occurred, Jupiter and our Sun would have been binary stellar sisters, and we probably would not be here now to tell the story. Our planet, and its seven lovely sisters, as well as all of the moons and smaller objects dancing around our Star, would not have been able to form. However, Jupiter failed to reach stardom. After its brilliant, sparkling birth, it began to shrink. Today, Jupiter emits a mere.00001 as much radiation as our Sun, and its luminosity is only.0000001 that of our Star.
The very productive Cassini mission might attain some indirect information by analyzing the ring arc material--however, it is unlikely to come close to the little moon again before the mission ends in 2017.
The surface of our Moon's near-side is dominated by the bewildering and unique Procellarum region, and this area is characterized by numerous ancient volcanic plains, low elevations, and a strangely unique composition.