根据给定的文本段落，写一个1-2句简洁的总结。 
下面是一段文本段落： 
太阳系最外层的行星是冥王星，它是一个矮行星，太阳系中第二小的行星。它的轨道长达3.67亿英里，离太阳最远的轨道点在49亿英里以外。它的自转周期长达约6.4地球日，公转周期248.1地球年。此外，它有5颗卫星。
Pluto is the farthest and second-smallest dwarf planet in the Solar System, with an orbit of 3.67 billion miles and a furthest distance from the Sun at 4.9 billion miles. Its rotational period is around 6.4 Earth days and it takes 248.1 Earth years to complete its full orbit, and it has five moons.