Stability of the Solar System one point, the two may fall into sync, at which time Jupiter's constant gravitational tugs could accumulate and pull Mercury off course with 1–2% probability, 3–4 billion years into the future. This could eject it from the Solar System altogether or send it on a collision course with Venus, the Sun, or Earth. Another example is Earth's axial tilt which, due to friction raised within Earth's mantle by tidal interactions with the Moon (see below), will be rendered chaotic at some point between 1.5 and 4.5 billion years from now. Objects coming from outside the solar system can also affect
The Secret of the Ninth Planet The Secret of the Ninth Planet The Secret of the Ninth Planet is a science-fiction novel written by Donald A. Wollheim and first published in the United States in 1959 by the John C. Winston Co. Wollheim takes his heroes on a grand tour of the solar system as that team struggles to prevent an alien force from blowing up the sun. This is the last of three juvenile novels that Wollheim wrote for Winston, the other two being "The Secret of Saturn's Rings" and "The Secret of the Martian Moons". This is one of the thirty-five juvenile novels that