It is the smallest.
Mercury is the smallest planet compared to the other ones
Mars is the second-smallest major planet (Only Mercury is smaller).Planets in order of size, smallest to largest :MercuryMarsVenusEarthNeptuneUranusSaturnJupiter(see related link)
Mercury is the smallest of the 8 major planets. It is smaller in size than Jupiter's moon Ganymede, or Saturn's moon Titan. But it has a greater mass than those moons due to its higher average density.
In order from biggest to smallest it goes Jupiter, Saturn, Neptune, Uranus, Venus, Earth, Mars, and Mercury.
Saturn is the second-largest planet in our solar system, with a mass about 95 times that of Earth. In terms of mass ranking among the planets, it follows Jupiter, which is the largest planet, and precedes Uranus and Neptune. The order of mass from largest to smallest is Jupiter, Saturn, Uranus, Neptune, Earth, Venus, Mars, and Mercury.
Earth is a fairly small planet. It is neither the biggest nor the smallest, as there are literally billions of billions of planets.
Mercury. Mercury takes 88 days to go around the sun, so its year is 88 solar days.
Uranus is the 3rd to largest planet.
Larger than: -Mercury -Mars -Pluto (I know it isn't a planet anymore!) Same size as: -Earth Smaller than: -Jupiter -Saturn -Uranus -Neptune
Because it has no atmosphere and thus no greenhouse gases. Greenhouse gases absorbs infrared heat emitted by an object and redistribute the energy throughout out a planet. Since there are no greenhouse gases present on Mercury, the energy absorbed by the planet can also escape the planet at a much greater rate into the vacuum that is space, thus keeping the surface temperature of the planet well below freezing
90th
Neptune is the fourth largest planet in our solar system, after Jupiter, Saturn, and Uranus. It has a diameter of about 49,244 kilometers, making it slightly smaller than Uranus.