It is the biggest planet in our solar system and is even considered the oldest. That's because it formed from the leftover dust and gases during the sun's formation over 4.5 billion years ago. And get this, Jupiter has the shortest days of all the planets, spinning around on its axis in just 10.5 hours, while Earth takes 24 hours. But what really makes Jupiter fascinating are those cool stripes and swirls on its body. Those are actually cold, windy clouds of ammonia and water floating on an atmosphere made of helium and hydrogen. It's like a giant, swirling masterpiece in space.