Mars, the fourth planet from the Sun, is a harsh and arid world. It is known for its frigid temperatures and desert landscape. It is one of Earth’s closest celestial neighbors, alongside Venus. Mars is one of the easiest planets to spot, standing out in the night sky as a bright red dot.
The name Mars originates from the Romans, who associated its fiery red color with their god of war. In reality, the planet exhibits a variety of colors, including brown, gold, and tan at its surface. However, its overall reddish appearance is attributed to the oxidization (or rusting) of iron in the rocks, regolith (Martian “soil”), and dust.
Mars in true color, taken by the Emirates Mars Mission on August 30, 2021. Credit: CU/LASP EMM/EXI ITF/Kevin M. Gill.
Mars is the seventh largest planet in our solar system, with a radius of 2,106 miles (3,390 km), making it roughly half the size of Earth. The surface gravity on Mars is only 37.5 percent of Earth’s.
In terms of rotation, Mars completes one spin every 24.6 hours, similar to Earth’s 23.9-hour day. Martian days are called sols, a shorter term for “solar day.” Mars is, on average, about 50 percent farther from the Sun than Earth. This greater distance results in a longer Martian year, spanning 669.6 sols, equivalent to 687 Earth days.
Size comparison: Earth and Mars
Mars has two small moons, Phobos and Deimos, believed to be captured asteroids. These moons have an irregular shape, resembling potatoes, as they lack the mass needed to form into spherical bodies.
Compared to Earth, Mars has a much thinner atmosphere, which reduces its ability to retain heat near the surface. Temperatures on Mars vary greatly, ranging from 70°F (21°C) to -225°F (-143°C). On average, the surface of Mars is bone-chilling at -81°F (-63°C).
Over time, Mars has undergone significant transformations in its landscape due to volcanoes, impact craters, crustal movement, and atmospheric conditions like sweeping dust storms. These dynamic forces have shaped Mars into a world of unique topographical features. Notably, it hosts Olympus Mons, the largest volcano in the solar system, towering three times taller than Earth’s Mt. Everest. Additionally, Mars boasts Valles Marineris, an enormous canyon system stretching a distance equivalent to the span from California to New York.
Viking 1 Orbiter image of Olympus Mons. Credit: NASA/JPL-Caltech/USGS.
Long ago, Mars witnessed the flow of water. Robotic rovers have discovered compelling proof that billions of years in the past, the planet’s surface was adorned with lakes and rivers of liquid water. This means Mars once possessed a denser atmosphere and retained enough warmth for liquid water to exist. However, the present conditions on Mars differ. While water ice is abundant beneath the surface and within the polar ice caps, no significant bodies of liquid water exist on the planet’s surface today.
Curiosity’s view of Martian soil and boulders after crossing the “Dingo Gap” sand dune. Credit: NASA/JPL-Caltech/MSSS.
NASA has a fleet of vehicles exploring Mars, including the Curiosity and Perseverance rovers, the InSight lander, and the Ingenuity helicopter. In addition to NASA, other countries have also made significant contributions to Mars exploration. In 2021, The United Arab Emirates’ Hope orbiter arrived, followed by China’s Tianwen-1 mission with an orbiter, lander, and rover. European and Indian spacecraft are also studying Mars from orbit.
With the combined efforts of multiple nations, Mars remains a focal point for scientific exploration, allowing us to deepen our understanding of this neighboring world. The ongoing exploration of Mars continues to uncover fascinating discoveries and pave the way for future missions.
Words of Wisdom
“The first human beings to land on Mars should not come back to Earth. They should be the beginning of a build-up of a colony/settlement, I call it a ‘permanence’.” —Buzz Aldrin
“If there was an observer on Mars, they would probably be amazed that we have survived this long.” —Noam Chomsky
“Problem is (follow me closely here, the science is pretty complicated), if I cut a hole in the Hab, the air won’t stay inside anymore.” ―Andy Weir, The Martian
Bibliography
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