The biggest question scientists have today is whether microscopic life exists beneath the Martian surface. As early as 1534 BCE, Mars was a subject of speculation by Egyptian astronomers. In the 17th century, Galileo was the first to view Mars via telescope. And it wasn’t until the mid 17th century that we began to truly study Mars with precision. It’s been an exciting journey piling up all the evidence and putting together the pieces of a puzzle. The history of Mars observation is a fascinating story that tells of a planet that is much more than just “Red.”
"The Red Planet" as we know it today is actually one of the more interesting spots in the solar system. And of paramount importance, it is much like Earth in many ways. For example, its length of day is 24 hours. It has seasons like Earth. It has predictable weather patterns like Earth. And yet, it is so different from Earth in many ways. This is why for hundreds of years we have sought to answer the questions: Did it ever have life? Can it sustain life? Does it have water? What is the planet’s history?
It’s no surprise that NASA is aiming for human missions to Mars sometime in the 2030s. Of all the planets, Mars is probably the best place to start if we want to begin colonizing other planets in our solar system. By the end of this article, I’ll have you ready to pack up all your things and move to Mars tomorrow. Let’s get this thing started! Where are the commercial interstellar-spacecraft already?
15 The Largest Volcano In The Solar System
Mars is home to incredibly large volcanoes. Mars’ uppermost solid crust moves differently than Earth’s. As Mars’ magnetic field faded away, plate tectonics ceased altogether and its crust would no longer fold or move. Hotspots, like Olympus Mons, the largest volcano ever discovered in the universe, remained in the same areas for over four billion years. Volcanoes on Mars are 10 to 100 times larger than the volcanoes on Earth.
Olympus Mons is also the second highest mountain in the solar system. Known as a “shield volcano,” its composition comes entirely from layers of lava, continually flowing, drying and piling. For scale, Olympus Mons is two and a half times taller than Mount Everest and covers an area about the size of Italy (120,000 sq mi). An observer standing on the surface of Mars, no matter where they are, would never be able to view the entire profile of the volcano.
14 The Seasons of “Terrestrial” Mars
Mars and Earth are very similar to each other in striking ways, hence the term “terrestrial.” In fact Mars and Earth have the closest "axial tilts" of any of the planets in the solar system. For us, this means Mars has seasons much like Earth does.
Mars has the seasons of spring, summer, autumn, and winter, just like Earth. And its southern and northern hemispheres have summer and winter at opposing times. The Martian year is about two Earth years (or 687 days). Each Martian season is an average of 167 days long. The weather ranges from long and cool winters (avg -109.3°F), to warm and short summers (avg 21.7°F). And because Mars doesn’t have any oceans, and lacks large bodies of water, the weather tends to repeat itself from year to year. In fact, Mars’ weather patterns are much more predictable than the weather here on Earth.
13 Earth-like Hurricanes
On April 27, 1999, a team of astronomers detected an enormous cyclonic storm with the help of the Hubble Space Telescope. NASA’s Viking program had detected similar storms 20 years earlier. But this storm was three times larger than the largest previous detected Martian hurricane. Since 2001, there have been at least three more similar cyclones detected around the same area. Always in the North polar region of Mars.
This particular 1999 storm was unlike any other. Mars is famous for dust storms. But this one came composed only of water ice clouds. Astronomers say it was much like the hurricanes we experience on Earth. The 1999 storm was about 1100 miles east to west, 900 miles north to south, and the eye of the storm was about 200 miles in diameter. Experts say that these storms happen only during Mars’ summer season, and they only last for a few days before dissipating.
12 The Infamous Cydonia Face
In 1975, NASA launched Viking 1, the first spacecraft to successfully land on Mars. Viking 1's mission was to thoroughly investigate the surface of Mars and make headway for its sister-craft Viking 2. While orbiting around the 13,236 mile red Martian surface, it snapped a photo that astonished scientists back at the Jet Propulsion Lab. What they saw while looking at their computer monitors was something resembling a human face. A few people thought the Face was de facto evidence for life on Mars. Perhaps an ancient artifact left by mysterious Martians, like the Egyptian pyramids.
Scientists soon realized the true nature of the mysterious Face. They discerned it to be a Martian mesa, explaining that its peculiar shadows on its flat top gave “the illusion of eyes, nose and mouth.” "The Face" soon attracted popular attention. So in 2001, NASA felt compelled to take another photo, utilizing the technological advancements of the "Mars Global Surveyor" (MGS).
11 The Phoenix Detects Snow
In 2007 the Jet Propulsion Laboratory, the University of Arizona and NASA joined forces to initiate the Mars Scout Program. Included in the partnership were universities from the U.S., Canada, Switzerland, Denmark, Germany, the United Kingdom, and Finland. It was the perfect match of academia, government, and industry. Its mission was to determine whether Mars can support microscopic life and to research the history of water on the red planet. At that juncture, it was some of the most sophisticated and advanced technology ever sent to Mars.
On May 25, 2008 the Phoenix made the first touchdown ever on Mars' polar region. Four months after its monumental landing on Mars, the Phoenix observed snow falling from thin white clouds about two-and-a-half miles above the lander’s meteorological station. This was the first time scientists knew of two things: Mars has polar clouds and Mars has snow.
10 Climate Changes
“Results show that Mars is not a dead planet, but it undergoes climate changes that are even more pronounced than on Earth,” said planetary scientist Dr. James Head of Brown University). Here on Earth, we are spinning 1,040 miles per hour. As we are spinning, the Earth’s axis wobbles, causing the north and south poles to move in a large circle. Besides Earth, and the moons of Saturn and Neptune, Mars is the only planet in the solar system that undergoes global geological climate changes due to the wobbling of its axis and its eccentric rotation.
This causes many things e.g., melting and freezing polar caps and the appearance and disappearance of oceans and global warming. Mars’ axis tilt is also much more extreme than Earth’s. This means Mars has more extreme climate changes, because its two tiny moons cannot stabilize the host planet like Earth’s moon can.
9 Mars’ Ice Age
"Now we're seeing that Mars, like Earth, is in a period between ice ages,” said Dr. James Head. The photo above shows what Mars probably looked like about 400,000 to 2.1 million years ago, during an ice age period. The Mars Global Surveyor and several specialists have been closely studying the surface of mars for more than 15 years. Many have concluded that Mars is still in the process of retreating from a recent ice age.
Unlike the ice ages on Earth, Martian ice ages happen when polar caps get warmer. Water from polar ice vaporizes into the atmosphere and comes back down at lower latitudes (equal to Houston or Egypt on Earth). As the vaporized water covers the ground, it takes the form of frost or snow, heavily mixed with dust, covering the surface a few meters or yards high. The bumpy landscape then resembles the surface of a basketball (or an Antarctic terrain).
8 Mars’ Northern Lights
I have to tell you about solar wind. Solar wind is “wind” released from the atmosphere of the Sun. It can reach up to one million miles per hour and it is flying around everywhere within our solar system. Earth is largely protected from solar wind because of its magnetic field, which tells the wind to “talk to the hand” (it deflects wind). Mars on the other hand (no pun intended), has had up to a third of its atmosphere stripped away by solar wind, because Mars has no magnetic field.
And I’m sure you already know about those amazing light shows you can see on a clear night. Maybe somewhere in Australia, or New Zealand. Well, Mars gets the “Northern Lights” show too. The “lights” are also deeper in the atmosphere than the lights on Earth. They dip down 37 miles above the surface, lower than any aurora found on any other planet.
7 The Color of The Martian Sky
Like its counter-intuitive ice age phenomenon, Mars' morning and afternoon sky is the opposite of what we experience on Earth. On Earth we’re all familiar with the sunset. Usually the sky is blue-ish or purple-ish, and in the near vicinity of the sun the sky turns reddish or orange-ish. Mars’ sunsets and sunrises feature a sky that is mostly “pinkish-red” in color. And very near the setting sun's vicinity, the human eye detects a color that is blue.
Basically, Mars’ skies come in many colors. During the day, the sky is “butterscotch”. Or we can say yellow-brown. Or we could say the sky is orange. Scientists say the "butterscotch" color of Mars’ sky comes about because of all the dust particles in the atmosphere, which also causes a longer delay of darkness and light (compared to Earth), right after and before the sun passes the horizon each day.
6 Epic Dust Storms
In 1971, the Mariner 9 spacecraft touched down on Mars’ surface with the intentions of taking the best pictures of Mars anyone had ever seen. But instead, the spacecraft found itself amid a global giant dust storm engulfing the entire planet. The only thing the spacecraft’s cameras could depict was Olympus Mons (the largest volcano in the solar system). The epic dust storm raged on for the rest of the month.
And thus began our knowledge of such storms. Wind speeds are typically around 30-50 mph, with gusts of wind up to 60 mph. Following the 1971 dust storm, scientists have been able to predict when and where the Martian dust storms will happen fairly accurately. Some dust storms even repeat in about the same site two years in a row. Chances of a global Martian dust storm in any given year are about one in three.
5 The Largest Grand Canyon In The Solar System
Located along the equator of Mars, Valles Marineris is the largest grand canyon in the solar system. It is very similar to our Grand Canyon in Arizona, only it is much larger. Our Grand Canyon in Arizona measures 500 miles long, 18.6 miles wide and one mile deep. On the other hand, Mars’ Grand Canyon (Valles Marineris) measures 2,500 miles long, 120 miles wide and four miles deep. The only similar geological formations that we could think of as being bigger are the sea floor cliffs and valleys located deep deep deep inside the Earth’s oceans, e.g., the Mid-Atlantic Ridge. But those don’t really count.
Since the 1970s, scientists have been eager to equate any formation on Mars with water. But today most scientists agree that Valles Marineris formed much like our canyons. Evolving from tens of millions of years of volcanic eruption, tectonic plate movements and erosion.
4 Mars Was “Habitable” In The Past
But does life exist on Mars? Or did it exist in the past? We don’t have clear evidence that life has ever existed on Mars. We do know that it “could” have existed. There is speculation of a possible ocean that existed 3.8 billion years ago dubbed “Oceanus Borealis.” It could have covered anywhere from 19-36% of Mars’ northern hemisphere. Along with this hypothesis is the idea that four billion years ago Mars was warm and wet, and could have hosted life. But sadly, that is mostly unsubstantiated. The real story is probably somewhat different. There are also theories that meteorites once fell on Mars and made conditions apt for life. Or that life still exists today frozen underneath the surface.
What we do know is that Mars did have water in abundance. And we have real evidence of ancient river valleys, deltas, lake beds and life-sustaining nutrients.
3 The Many Exploits of "Curiosity"
"Curiosity" is a car-sized robot-on-wheels sent to Mars in 2011. Its mission is to find organic compounds, biological processes, analyze the Martian atmosphere, and help scientists answer the great questions about Mars. It landed on Mars in 2012 and its mission will go on indefinitely.
Curiosity has discovered a wealth of information about Mars' habitability factors. It identified almost every nutrient that is essential for life to exist, including sulfur, nitrogen, hydrogen, oxygen, phosphorus and "possibly" carbon. Curiosity also found evidence that suggests Mars had ancient lakes or stream beds that were not too salty to sustain life. It found sandstone beds that scientists say “seem similar” to microbial (microscopic life) induced structures found on Earth. And as another example, in 2013 Curiosity found samples of mud that “could” have hosted living organisms for tens of millions of years because of their neutral pH, low saltiness, and the essential nutrients contained within.
2 Flowing Salt Water On Mars?
In August 2011, only three months before Curiosity launched from Cape Canaveral, undergraduate student Lujendra Ojha found compelling evidence of liquid salt-water flows on the surface of Mars. What he found exactly were seasonal changes on steep slopes near the rims of a crater on Mars’ Southern hemisphere. After successive monitoring of the area, it looked as if there could be flowing water somewhere around there. It appeared is if the flows were increasing incrementally during the Martian summer and gradually fading away in the cold seasons; that is, recurring cyclically each year.
Scientists still don’t know much about the probable liquid salt water flows, dubbed “brines.” The leading hypothesis is that it really is a flow of very salty water. These observations are “the closest scientists have come to finding evidence of liquid water on the planet's surface today.” If it is water, scientists still aren’t exactly sure where the water is coming from.
1 Allan Hills 84001
We have discovered over 61,000 Martian meteorites. And each one fits neatly into a category. Allan Hills 84001 doesn’t fit neatly into any category. Since its discovery, it has been a source of constant controversy.
Allan Hills 84001 is about 4.1 billion years old. And based on a 2005 analysis, originates from Valles Marineris (the giant grand canyon). Through chemical analysis we found it could be from a period when liquid water existed in abundance on Mars. And a study conducted in 2011 finds that the meteor's carbonate fell from a Martian sky of around 64°.
When put under a microscope, tiny bacteria, or something that resembles tiny bacteria, shows up. Evidence is still inconclusive. But Allan Hills 84001 could be the first evidence ever of extraterrestrial life. Skeptics say the possible bacteria could be only contamination from the Earth. But at the time of its discovery the "bacteria" was smaller than any cellular life ever known.