Red Planet Day

Red Planet Day is observed around the world on November 28. It is dedicated to Mars, one of the most extensively studied planets in the solar system. Numerous robotic missions have explored the Red Planet, expanding our understanding of its history, climate, and potential to have supported life.

History of Red Planet Day

November 28 was chosen to commemorate the launch of NASA’s Mariner 4 spacecraft in 1964. The probe flew past Mars in July 1965, passing approximately 9,846 kilometers, or 6,118 miles, above its surface and returning the first close-up photographs of another planet.

Mariner 4 transmitted 22 images showing a dry, heavily cratered landscape. Before the digital data could be fully processed, members of the mission team manually colored numbered strips to create an early representation of one image. The mission also provided evidence that Mars had a very thin atmosphere and harsher surface conditions than many scientists had expected.

Mars continues to inspire scientists, engineers, writers, and filmmakers. The film The Martian, starring Matt Damon, tells the fictional story of an astronaut stranded on Mars who must use science and limited resources to survive until he can be rescued.

Interesting Facts About Red Planet Day

• The atmospheric pressure on Mars is less than 1% of the average pressure at sea level on Earth.
• A Martian year lasts approximately 687 Earth days.
• Mars has about one-tenth of Earth’s mass, and its surface gravity is approximately 38% of Earth’s.
• Temperatures on Mars vary widely and can fall below −125 °C, or −193 °F, near the poles during winter.
• Ancient river valleys, lakebeds, and mineral deposits indicate that liquid water once existed on the Martian surface.
• Carbon dioxide gas can escape from beneath seasonal ice near the south pole, creating geyser-like eruptions.
• Fine iron-rich dust gives Mars its reddish color and often makes the sky appear yellow, orange, or pink.

How to Take Part in Red Planet Day

• Read about past and present Mars missions and the discoveries made by orbiters, landers, and rovers.
• Join an astronomy club or online community to discuss Mars exploration.
• Visit a planetarium, science museum, or observatory offering programs about the solar system.
• Host a Mars-themed gathering with red decorations, planetary models, or space-related activities.
• Watch documentaries or films about Mars and discuss which parts are based on real science.

When Is Red Planet Day in 2026?

Red Planet Day is observed on November 28 each year.

Observations