Which of the following is not a terrestrial planet?
A) Earth
B) Mars
C) Saturn
D) Venus
The correct answer and explanation is:
Correct Answer: C) Saturn
Terrestrial planets are those that have a solid rocky surface. These planets are typically composed of silicate rocks or metals and have relatively high densities, slower rotation, little or no rings, and few or no moons. The four terrestrial planets in our solar system are Mercury, Venus, Earth, and Mars. They are also the four innermost planets, located closest to the Sun.
Earth is a classic example of a terrestrial planet. It has a solid crust, active geology, and supports life. Mars, often called the Red Planet, is also terrestrial, with a rocky surface, polar ice caps, and signs of past water activity. Venus, although covered in thick clouds of carbon dioxide and sulfuric acid, has a rocky surface and a structure similar to Earth’s.
Saturn, on the other hand, is a gas giant. It is not a terrestrial planet. It is composed mostly of hydrogen and helium and lacks a true solid surface. Saturn is the sixth planet from the Sun and is best known for its prominent ring system, which is made up of ice, dust, and rock particles. Unlike terrestrial planets, gas giants have thick atmospheres, many moons, and fast rotation rates. They are much larger in diameter and mass but have much lower densities.
Because Saturn lacks a solid rocky crust and instead has a dense atmosphere surrounding a possible core, it does not fit the definition of a terrestrial planet. Its physical characteristics such as size, composition, and structure are very different from those of Earth, Mars, or Venus.
In summary, Earth, Mars, and Venus are all rocky terrestrial planets, while Saturn is a gas giant, making it the correct answer as the planet that is not terrestrial.
