Mars occupies the fourth closest position to the sun in the solar system. Earth, along with Venus and Mercury, are all closer. Mars is bordered by both Earth and Jupiter.
Mars is a much smaller planet than Earth, but one of the most similar in the solar system. It is the most explored planet so far, with multiple probes landing on and searching the planet.
Mars is one of the few planets that contains water (in the form of ice), and may be suitable for sustaining life. It is easily identified by its red appearance, which is a result of the high concentration of iron oxide on the planet's surface.