Mercury:
- Mercury is the closest planet to the Sun, and it is the smallest planet in our solar system.
- It is named after the Roman messenger god because it moves quickly across the sky.
- Mercury has a diameter of about 4,879 kilometers, making it only slightly larger than Earth's moon.
- It has a very thin atmosphere, almost negligible, which means that it cannot trap heat and has extreme temperature variations. During the day, the temperature can reach up to 430 degrees Celsius, while at night it can drop to -180 degrees Celsius.
- Mercury's surface is covered in craters, similar to the moon, and it also has cliffs and escarpments. The Caloris Basin is one of the largest impact craters on Mercury.
- Despite its small size, Mercury has a relatively large iron core, which makes up about 70% of its mass. This core generates a weak magnetic field.
- The planet has a slow rotation, taking about 59 Earth days to complete one rotation on its axis. However, it orbits the Sun in just 88 Earth days, resulting in a longer day than year on Mercury.

Venus:
- Venus is the second planet from the Sun and is the hottest planet in our solar system.
- It is named after the Roman goddess of love and beauty because of its brightness in the sky.
- Venus has a diameter of about 12,104 kilometers, making it similar in size to Earth.
- It has a thick atmosphere composed mainly of carbon dioxide, with traces of nitrogen and sulfuric acid. This atmosphere creates a runaway greenhouse effect, resulting in extreme temperatures that can reach up to 470 degrees Celsius, making it hotter than Mercury despite being farther from the Sun.
- The planet's surface is covered in volcanic plains, mountains, and impact craters. Venus also has a dense layer of clouds that completely obscures the surface from view.
- Venus rotates very slowly, taking about 243 Earth days to complete one rotation on its axis. It also orbits the Sun in about 225 Earth days, resulting in a longer year than day on Venus.
- Venus does not have any moons and has no magnetic field. However, it has a thick atmosphere that creates a strong atmospheric pressure at its surface, similar to being underwater at a depth of 1 kilometer on Earth.