Mercury is the smallest and innermost planet in the Solar System.
Its orbit around the Sun takes 87.97 days, the shortest of all the planets in the Solar System.
It is named after the Roman deity Mercury, the messenger of the gods.
Venus is the second planet from the Sun. It is named after the Roman goddess of love and beauty.
Venus orbits the Sun every 224.7 Earth days.
As the second-brightest natural object in the night sky after the Moon, Venus can cast shadows and, rarely, is visible to the naked eye in broad daylight.
Earth is the third planet from the Sun.
Earth orbits around the Sun in 365.256 days, a period known as an Earth sidereal year. During this time, Earth rotates about its axis about 366.256 times.
Earth's axis of rotation is tilted with respect to its orbital plane, producing seasons on Earth.
Mars is the fourth planet from the Sun and the second-smallest planet in the Solar System after Mercury.
In English, Mars carries a name of the Roman god of war and is often referred to as the 'Red Planet'. The latter refers to the effect of the iron oxide prevalent on Mars' surface.
Mars is a terrestrial planet with a thin atmosphere.