Red Planet Day is celebrated every year on November 28 across the world to commemorate the launch of the Mariner 4 by NASA, a robotic interplanetary probe, and Jet Propulsion Laboratory (JPL) on November 28, 1964. This spacecraft became the first spacecraft to fly past Mars and was designed for flying past planets. Mariner 4 spacecraft became the first mission to successfully take photos of Mars.

Mars is also known as Red Planet due to the iron oxide or rust on the surface of this planet that gives a reddish appearance. The main aim of this international day is to spread awareness about Mars and the fascinating findings of this planet across the world. Mars is the second-smallest planet in the Solar System that is larger than only Mercury and is the fourth planet from the Sun in the Solar System. It is a terrestrial planet with a thin atmosphere that contains a crust mainly composed of elements which are similar to the crust of the Earth.

Olympus Mons is the highest known mountain and the largest volcano on Mars in the Solar System. Mars may view with the naked eye from the Earth in a reddish color. The appearance of the reddish color of Mars due to the iron oxide is present on the surface of Mars and is also called as Red Planet. It is the brightest object in the sky of the Earth with an apparent magnitude reaches 2.94.  The main aim of this international day is to inform people about important facts about Mars all around the world.