J is for Jupiter

Jupiter is the largest planet in our solar system.  It is an oblate spheroid (my favourite shape name,) same as Earth, meaning it bulges at the equator.  There is a visible storm on its surface called the Great Red Spot, known to have existed since at least the 17th century (bad ass.)  Also, it has at least 63 moons, the largest of which (Ganymede, one of the four discovered by Galileo) has a diameter greater than that of Mercury.

Pretty cool, Jupiter.  Pretty cool.