This gas giant is 11 times the diameter of Earth and 300 times the mass. If you took all the other planets in our solar system and “smushed” them together to form one planet, it would still be smaller than Jupiter.

So yes, Jupiter is big. But a bully? Yes, to chunks of rock and ice that orbit near Jupiter. The planet’s powerful gravity can pull them into their doom or bat them out of the solar system so they have no chance of colliding with Earth. To us, Jupiter is more of a big brother — our own personal planetary forcefield. That’s a good thing, since more comets smash into Jupiter than any other planet in the solar system.

In fact, this past July an amateur astronomer in Australia noticed Jupiter had a “black eye” — a black spot the size of the Pacific Ocean left in the planet’s atmosphere when a comet was lured to its demise by Jupiter’s gravity. Good news for us; otherwise that comet would have kissed our planet good night, right? Maybe. Maybe not. Jupiter, say some astronomers can be a friend and a foe.

The “Big Bully” is more likely to step up to the bat and hit a home run for Earth if a comet comes from the Oort Cloud, a swirling nest of cosmic debris far beyond the orbits of our planetary family. But when it comes to giant chunks of ice and rock in the Kuiper Belt (just beyond Neptune’s orbit), Jupiter’s gravitational pull may “bunt” them into tighter orbits toward Earth. Before you start building that giant catcher’s mitt, keep in mind that our planet gets hit by one of these big cosmic fastballs only about once every 100 million years.