If you want to see the highest planetary mountain in the solar system, it's better to pack your bags because you certainly won't see it from the familiar atmosphere of the Earth. The highest planetary mountain in the solar system is located in the western hemisphere of Mars and rises an astounding 1
Even without the extra height of the dry seabed, Olympus Mons is still two and a half times as long as Mount Everest on Earth and a few miles longer than the second highest mountain on Mars.
Strangely enough, the highest mountain in the solar system is not even on a main planet, but on the huge little planet / asteroid 4 Vesta. 4 Vesta is 326 miles (525 kilometers) in diameter and sports a mountain, Rheasilvia Mons, which is 14 miles (22.5 kilometers) high.
While the mountain on 4 Vesta is the highest in terms of rough height, the scale of it is really impressive compared to the body on which it is located. If Mount Everest was the same size as Rheasilvia Mons (relatively speaking), it would tower approximately 340 miles (547 kilometers) above sea level.