Exploring the Inner Solar System: Venus, Earth, & Mars

Continuing the exploration of the inner Solar System, you will learn about Venus, Earth, and Mars in this article. Facts and trivia may include finding out which planet is the hottest in the Solar System, as well as who is the densest out of all the inner planets.


Venus is often called the “sister” planet to Earth, as it is very close in size. The planet also shares the same thick silicate mantle that appears about the iron core. The atmosphere is substantial and some proof has surfaced that internal geological activity has taken place. A difference from Earth is seen in the dryness of the planet, as it is much drier than Earth with an atmosphere that is 90 times denser. There are no natural satellites with Venus. Interestingly, it is the hottest planet in the Solar System, as the surface can reach temperatures more the 400 degrees Celsius. Scientists believe that this takes place because of the amount of greenhouse gases present in the atmosphere. There is also no conclusive evidence that shows any geological activity occurring on Venus. Since there is no magnetic field on the planet, researchers believe that erupting volcanoes routinely rejuvenate the atmosphere.

Facts About Venus

Venus is the sixth largest planet in the Solar System.

Flat plains, highland regions, and rock depressions characterize the surface of the planet.

Venus rotates very slowly and one day on Venus equals 243 Earth days.

More than 20 spacecrafts have paid a visit to Venus.


The largest and densest of the inner planets is the one that we live on and is the only planet known to possess geological activity that is currently thriving. As the only planet known to sustain life, Earth is a pretty important place to be in the Solar System. Out of all the terrestrial planets, Earth is quite unique, as it possess a hydrosphere of liquid. The observation of plate tectonics is also unique to Earth, as it is the only planet to possess this characteristic. The atmosphere is intensely different from other planets, as the presence of living creatures has altered it over the years. 21% free oxygen has been the result of this. With one satellite (the Moon), this terrestrial planet within the Solar System is linked to the only significant satellite in size.


The size of Mars is smaller than Venus and Earth. It is home to an atmosphere that mostly displays carbon dioxide. The surface has scattered volcanoes about its land with names, such as Olympus Mons. Rift valleys connected to the planet are also named, such as Valles Marineris. Research proves that geological activity may have taken place on the planet until recent times. There are two very small natural satellites attached to Mars , Deimos and Phobos. These two have been thought to have succumbed to asteroids.

Facts About Mars

Mars is known as the seventh largest planet in the Solar System.

The red, dusty landscape of Mars is the reason why this planet is referred to as the Red Planet.

The planet was named after the Roman mythological god of war.

Mars is home to polar ice caps, which are made of solid carbon dioxide, which move as the seasons change.