Smallest planet: What are the smallest planets

What are the smallest planets that exist? Mercury is the smallest planet in the Solar System. It has a diameter of 4,879 kilometers, three times smaller than Earth's. It is so small that even Ganymede, a satellite of Jupiter and the largest in the Solar System, at 5,268 km in diameter, is larger than Mercury. Let this serve as context. We have compiled the list in descending order of size and next to each name we will indicate the diameter of the planet in question. And now, without further ... If you’re talking about planets in our Solar System, that’s easy to answer: the smallest planet is Mercury. Mercury is the smallest of all the eight planets whether you’re looking at 'size' in terms of radius, volume or mass. 5. Our home planet Earth is the fifth largest of the eight planets and measures in at 12,756 km in diameter. This means that Earth is actually approximately 2.6 times the diameter of the smallest planet, Mercury. Another size comparison puts Earth at 3.67 times the diameter of the Moon. 6. The smallest planet in regards to both mass and volume is Mercury — at 4,879 km across and 3.3010 x 10 23 kg, this tiny world is nearly 20 times less massive than Earth, and its diameter is about 2½ times smaller. In fact, Mercury is closer in size to our Moon than to Earth.