10 Fascinating Facts About Mars

Due to its red color, Mars has always been associated with blood and war. The Ancient Greeks named the planet after the God of War, Ares, as did the Romans, which is what we know it as now, Mars. Other ancient cultures also named the planet based on its color, with China’s astronomers naming it “the fire star,” and Egyptian priests calling it “Her Desher,” or “the red one.” Mars’ famous red appearance is due to iron oxide (rust) dust which is covering its surface. The rocks and soil covering Mars are mainly built up of iron, but also a small amount of other elements. The dust was created by the rocks and soil becoming eroded by wind (and perhaps spread by water), and the iron within this dust reacted with oxygen to create its iconic coloring. Storms carry the dust into the atmosphere, giving the sky an orange hue.

Despite its distance from Earth, Mars was sighted by Ancient Egyptian astronomers and was recorded as a wandering object in the sky. By 1534 BC, they were familiar with the retrograde motion of the planet. More and more detailed observations about the planet were made, and the first telescopic observation was by Galileo Galilei in 1610. Soon, astronomers were uncovering distinct features about our neighboring planet, including the polar ice caps, its rotation period and axial tilt. Improved telescopes in the 19th century then allowed for better observations, and soon it was being mapped in detail. Since the ’60s, we have sent multiple robotic spacecrafts to explore from orbit and the surface, with the fantastic Curiosity Rover landing in 2012. These probes have since helped us discover fascinating new information on a monthly basis, and it is intriguing to see what we will find next.

Unlike Earth, Mars has two moons, but neither are like our own moon as they are small and have an irregular shape. They have a composition like that of asteroids found elsewhere in the solar system, which leads NASA to believe that they are asteroids that Mars’ gravity snatched and forced into orbit many years ago. The moons are named after the twin brothers of fear and terror in Greek mythology, Phobos and Deimos (sons of Ares). It is believed that Phobos will have a (relatively) short lifetime, as in about 30 to 50 million years it will rip apart or crash into Mars’ surface due to the tidal force of the planet. If you were to stand on the equator of Mars, full Phobos would look roughly one third as big as our own full moon, whilst Deimos would look like a bright star or planet.

Mars is more similar to Earth than any other planet in the solar system, but there are also many huge differences. Like Earth, Mars has four seasons due to the tilt of the rotation axis, and it also has 24 hours in a Martian day. Whilst this may make it seem relatively similar, one key difference in terms of its orbit is that it takes almost twice as long to orbit the sun. A Martian year lasts 687 days, due to it being farther from the sun than Earth. This also means that the four seasons on Mars last roughly twice as long as they do on Earth. With its winter season reaching as low as -205 Fahrenheit, this makes it very different and harsher than Earth. During Mars’ lengthy summer season, however, the average temperature is 72 Fahrenheit, which many of us wouldn’t complain about.

There has always been talk about manned missions to Mars, but never as much talk as there currently is with NASA’s recent announcement and the arrival of Ridley Scott’s The Martian. It is thought that a realistic timeframe will be the early 2030s, but of course there are numerous challenges that must be overcome. A trip to the Red Planet takes around eight months, which is slightly longer than astronauts stay on the International Space Station. There would then be the mission on the planet itself, before another eight months to return home (provided it is not a “one way” trip). For comparison, the Apollo missions took around three days to reach the moon. The mission would take place when Mars is somewhere near its closest to Earth, and the closest it has ever been was in 2003 when they were “just” 34.8 million miles (56 million km) apart.

Dust storms occur on Mars when it is nearest to the sun, and these storms can last for months and cover the entire planet. During these storms, the temperature soars because the dust clouds absorb the sun’s heat instead of deflecting it, and average storms have winds of around 125 mph. These dust storms have caused concern for probes that have been sent to the Red Planet, with Mariner 9 arriving in 1971 during the biggest dust storm ever recorded; they had to wait a few weeks before starting the mission. Due to Mars having a very thin atmosphere (1% of Earth’s), these winds would feel like a gentle breeze. The problem, therefore, is not having material destroyed or being blown over, but instead the risk of fine dust in the air. This can decrease the power output of solar panels, which can impact rovers and would also impact manned missions.

Much like Earth, the Martian surface has been struck by large asteroids throughout history. Unlike Earth, however, there is low gravity on Mars which leads some of this debris to be ejected into space (with the rest falling back to the surface). This debris then moves around the solar system, with some of it landing on the surface of Earth. The technical name for these meteorites is SNC (Shergottites, Nakhilites, Chassignites), which are types of geologic composition. Some of the gases that were trapped in these meteorites were near identical to what the Viking landers (NASA space probes) sampled on Mars in the late ’70s. It is fascinating to think about the journey that this debris has gone on before finally reaching our own planet, and it also enables scientists to further study Mars before launching other space missions.

Earlier in 2015, NASA scientists announced that they had found evidence that a gigantic ancient ocean once covered nearly half the northern hemisphere of Mars shortly after it first formed 4.5 billion years ago. They believe it was a mile deep in some places, and held more water than Earth’s Arctic Ocean. This conjures up images of Mars being a warm and wet world, prime for containing some kind of life, which contrasts what scientists thought only 10 years ago, that flowing water was an erratic presence. This means that Mars has been wet for much, much longer than initially thought, and therefore perhaps habitable for longer as well. We always think of Mars as a dry, red and barren landscape, but this was clearly not the case, and from space it would have looked similar to Earth. Now just 13% of this remains, frozen in the polar caps.

Located just off the northwestern edge of the Tharsis bulge in the Western hemisphere, astronomers have found the largest known mountain in the entire solar system. Olympus Mons has a staggering height of 25 km (16 miles), and this makes it an astonishing three times as tall as Earth’s highest mountain, Mount Everest. It also has a diameter of around 600 km, making it roughly the same size as the state of Arizona. It has an odd and unsymmetrical shape, with many comparing it to the shape of a circus tent. Due to the size of Olympus Mons, its shallow slopes and the size of the planet, an observer standing on the Martian surface would not be able to see the entire mountain due to the curvature of the planet. It is also the youngest of the large volcanoes located on the Red Planet, having formed during Mars’ Amazonian Period.

You will have to have been living under a rock not to have heard it, but it is impossible not to include this fact as it is such a historical moment in the exploration of the Red Planet. In late September, NASA scientists announced that they had found evidence of flowing water on Mars. It was known that liquid water was once present on Mars (see #3), and there is frozen water in the polar caps, but it was not thought that there was presently liquid water on the surface of Mars. The water apparently flows only during the summer months, which was discovered by looking at light waves returned from seasonal dark streaks on the surface of Mars. This enables us to believe that it is at least possible to have a habitable environment there today, and it gives agencies such as NASA promising areas to search for microbes.