(download animation) Jupiter & it's moon Io
Jupiter i s the second largest body in our solar system. It is the largest planet which contains most of planatery mass of our solar system. For earth and it's nearby planets, it is called as "saviour" due to it's gravitational influence in surroundings. It works as a vaccum cleaner for the asteroids and other small size objects which come under it's gravitational zone. It results prevention of posibilities of asteroids to get collided into earth's atmoshphere.
It's moon "Io", is the most volcanically active world in the solar system. At times, it can be seen by large telescopes on earth.