The huge bounty of new data about the structure of our Solar system that has been acquired by NASA’s fleet of interplanetary spacecraft over the past 4 decades has greatly sharpened our understanding of the physical and chemical processes that were at work when the system was formed more than 4.5 billion years ago. Current missions include the Cassini-Huygens Mission to Saturn and Titan (2004- ), the MESSENGER mission to Mercury (2011- ), the Dawn mission to the giant asteroids Vesta and Ceres (2011- ) and the New Horizons mission to Pluto and its moons (2015- ).
In this lecture I summarize what has so far been gleaned from the various spacecraft missions. I show how much of the detailed structure of the planetary system and that of the regular satellite systems of Jupiter and Saturn can be explained by the author’s modern Laplacian theory of solar system formation. The basic premise of this theory is that the planetary and satellite systems condensed from concentric families of orbiting gas rings. These rings were cast off from the equators of the respective rotating proto-solar and proto-planetary gas clouds by a new physical process of supersonic convective turbulence which I devised in 1973. I also discuss how Pluto and its largest moon Charon were formed, including the 4 recently-discovered smaller moons of Pluto, orbiting beyond Charon, whose existence I had predicted more than 20 years ago in 1993 (Aust. J. Astron. Vol.5, p.111-119). Lastly, I describe how I had successfully predicted both the mass and exact location of the 4th planet of the nearby star HR8799 more than 2 years before its discovery in 2010!