Mars

Lore & Background

Mars formed approximately 4.5 billion years ago. Its geological history is divided into three primary periods: the Noachian (4.5 to 3.5 billion years ago), marked by impacts and possible water oceans; the Hesperian (3.5 to 3.3–2.9 billion years ago), dominated by volcanic activity and flooding; and the Amazonian (3.3–2.9 billion years ago to present), which continues today. The planet is seismically active, with marsquakes, and hosts extinct volcanoes including Olympus Mons, the tallest in the Solar System, and Valles Marineris, one of the largest canyons. A 2023 study suggests Mars may have had a ring system 3.5 to 4 billion years ago.

In Their Own Story

The emergency klaxons had been silent for hours now. Dr. Elena Vance stood at the observation window of Mars Station Alpha, watching the Von Braun's silhouette against the red planet's curve. The ship was supposed to be a triumph—TriOptimum's crowning achievement. Instead, it had become a tomb. She could see flickering lights in the ship's docking bay, but they weren't maintenance signals. They were wrong. Organic. The comms had been dead for three days, but she still checked every hour. Today, she heard something new: a wet, chittering sound from the air vents. She reached for her pistol, knowing it wouldn't be enough. The red dust on the window seemed to pulse, as if the planet itself was watching. Then the lights in her station flickered, and the chittering grew louder. She fired three shots into the vent grille. The noise stopped—but the dust kept pulsing.

Reader's Guide

Mars has been observed with the naked eye throughout history. The first flight to Mars was Mars 1 in 1963, but communication was lost. The first successful flyby was Mariner 4 in 1965. Mariner 9 entered orbit in 1971, the first spacecraft to orbit a body other than the Moon, Sun, or Earth. The first uncontrolled impact (Mars 2) and first successful landing (Mars 3) also occurred in 1971. Probes have been active on Mars continuously since 1997. Mars is often proposed for future crewed missions, though none are currently planned.

Did You Know?

• Mars has a significant axial tilt of 25 degrees, giving it seasons similar to Earth.
• A Martian solar year is 1.88 Earth years (687 Earth days), and a Martian solar day (sol) is 24.6 hours.
• Fine dust is prevalent across the surface and atmosphere, picked up by weak winds due to low gravity.
• The northern hemisphere consists of relatively flat plains, while the southern hemisphere has cratered highlands.