T he same thing happens to baseballs, footballs - anything you throw through the air. All that changes on Mars. The air pressure on the Red Planet is only about 0.2 inches of mercury at sea level, nearly 150 times less than that on Earth. With virtually no atmosphere to drag on the ball, its trajectory at the end of its flight will be pretty much what it was when it left the bat. And that alone might guarantee a home run record every inning.
Outfielders count on the ball dropping a little more vertically when it arrives on Earth.
On Mars, line drives and fly balls alike would be fearsome things, pretty much like standing in front of the batter and catching the ball the instant it left the bat. And pitchers will no longer be stars. Without aerodynamics that make sinkers, sliders, and curves possible, all they can throw are straight pitches. It's going to be big. The back fence better be three times as tall, too, or the outfielders might become high jumpers and find themselves in the parking lot when they try to snag the ball.