Red Planet Day, November 28, commemorates the anniversary of the launch of NASA's Mariner 4 spacecraft in 1964. This mission achieved a successful flyby of Mars, giving humanity its first close-up images of another planet. But long before this, Mars has held a fascination for humanity. As the closest planet to Earth, it can be viewed with the naked eye, appearing distinctly reddish in color due to the iron oxide dust covering its surface. Early records of Mars date back thousands of years to ancient Egyptian, Chinese, and Babylonian astronomers, who documented its motions and developed methods to predict its position. All this was based on observations with the unaided eye. However in 1610, Galileo Galilei made the first telescopic observation of Mars, marking a significant advancement in its study.
Improved telescopes in the 19th century enabled mapping of Mars, with the first map published in 1840 and more refined ones following in 1877. The idea of life on Mars became widely popular in the late 19th century, primarily due to the work of astronomer Percival Lowell who observed linear features that he speculated were a network of canals built by intelligent life. These turned out to be optical illusions, but the search for signs of life has remained. Since the 1960s, robotic spacecraft have explored Mars from orbit and its surface, while instruments across the electromagnetic spectrum continue to observe it. Martian meteorites found on Earth provide valuable insights into the planet's chemical conditions through laboratory analysis.
Mars is a world of extremes. Its surface consists of vast deserts, massive volcanoes like Olympus Mons (the tallest in the solar system), and an enormous canyon system, Valles Marineris, roughly 10 times longer, 20 times wider, and 5 times deeper, than the Earth’s Grand Canyon. Its surface temperature is incredibly cold, with average temperatures of -80 degrees Fahrenheit. The planet's atmosphere is very thin, containing more than 95% carbon dioxide and much less than 1% oxygen. It experiences wind and dust storms, ranging from small tornado-like storms to massive planet-wide events visible from Earth. Mars has significantly less mass than Earth, and so about one-third the gravity. A person who weighs 100 pounds on Earth would only weigh about 38 pounds on Mars. Despite these harsh conditions, evidence of ancient riverbeds, lake systems, and polar ice caps suggests that billions of years ago, the planet had conditions favorable for life.
NASA is currently exploring Mars with three orbiters studying the planet’s climate, surface features, radiation, and minerals. On the surface, the Curiosity rover, active since 2012, investigates the terrain. In 2021, the Perseverance rover arrived with advanced tools, including a system to produce oxygen from Mars’ carbon dioxide and a helicopter named Ingenuity to test powered flight. The ultimate goal is to send humans to explore Mars. The robotic missions serve to prepare for this, researching habitats, food production, and the effects of space living.
To learn more about Mars check out these books and the display on the third floor.