Space.com indicates that Neptune's diameter of 15,299 miles is fourth longest among the planets. At 102 trillion trillion kilograms, Neptune has the third-highest mass of the eight planets in the solar system. However, i... More »

www.reference.com Science Astronomy Planets

The average temperature on Neptune is -373 degrees Fahrenheit. Neptune is, on average, 2.8 billion miles from the sun, making it the eighth planet from the sun, which is one reason this planet is so cold. More »

Neptune is a giant planet comprised largely of helium and hydrogen gases. It is the furthest of the eight planets from the sun, and it takes about 165 Earth years for Neptune to complete a full orbit. Neptune is also kno... More »

Unlike other planets, Neptune does not really have a solid surface; it is made up of gases while its interior is made up of a rocky core, which is very hot. Neptune is quite unique since it glows even without sunlight. M... More »

Neptune has an average diameter of 30,598 miles, which is approximately almost four times Earth's diameter. In terms of mass, Neptune weighs approximately 102 trillion trillion kilograms, making it 17 times heavier than ... More »

The diameters of the planets are as follows: Mercury is 3,032 miles; Venus is 7,521 miles; Earth is 7,926 miles; Mars is 4,222 miles; Jupiter is 88,846 miles; Saturn is 74,898 miles; Uranus is 31,763 miles; Neptune is 30... More »

Neptune is the eighth planet from the sun, and it's about 2.8 billion miles away from the sun. This distance is roughly 30 times further away from the sun than Earth is, making Neptune a cold and dark planet. More »