Sisäplaneetat

Sisäplaneetat, also known as the inner planets, are the four planets closest to the Sun in our solar system. They are Mercury, Venus, Earth, and Mars. These planets are significantly smaller and denser than the outer planets, which are the gas giants Jupiter and Saturn, and the ice giants Uranus and Neptune. The inner planets are primarily composed of rock and metal, with Earth being the only one known to support life.

Mercury is the smallest and closest to the Sun, with a surface temperature that can reach up to 430 degrees Celsius. Venus, the second planet from the Sun, has a thick atmosphere that traps heat, making it the hottest planet in the solar system. Earth, the third planet, is the only known planet to have liquid water on its surface and a diverse range of life forms. Mars, the fourth planet, is often referred to as the "Red Planet" due to its reddish appearance, which is caused by iron oxide on its surface.

The inner planets have no rings and few moons, unlike the outer planets. They also have shorter orbital periods, meaning they complete their orbits around the Sun more quickly. The inner planets are believed to have formed closer to the Sun, where temperatures were high enough to prevent the formation of ice and gas, which are the primary components of the outer planets.