10 Reasons Why Mars Is a Dead Planet

Mars has long been the number-one place to explore for life beyond Earth. Only a few decades ago, many still assumed that life on the Red Planet was a near certainty. However, after many years of exploration, we now know more about the surface of Mars than the unexplored depths of the Earth’s oceans. We also know now that it’s highly unlikely any life currently exists on the barren, inhospitable surface of the Red Planet. That’s not to say that Mars didn’t host some form of life in its past. After all, it is widely assumed that the planet was once home to oceans, rivers and a much thicker atmosphere than it has now. Today, however, Mars is a dead planet, a lifeless desert world.

#1. Low Atmospheric Pressure

NASA

Since it lost its magnetic field between 3.7 and 4.2 billion years ago, the solar wind has been steadily eroding Mars’ atmosphere away. As a result, it now has an extremely low atmospheric pressure averaging at about 0.6 kilopascals. By comparison, Earth’s average atmospheric pressure at sea level is around 101.3 kilopascals. At these low pressures, water boils almost instantly, regardless of temperature. For an unprotected human being on the surface, this would be deadly within minutes, since blood would boil, and if the unfortunate individual tried to hold their breath, their lungs would rupture. While some forms of life can survive these low pressures, almost none of them can reproduce, let alone thrive.

#2. Very Low Temperatures

NASA

Mars’s average surface temperature of -63°C makes it as cold as the frigid Siberian tundra in the middle a winter night. However, Mars is not always so cold, and maximum temperatures can reach a cosy 35°C while minimum recorded temperatures plummet to -153°C. It might seem that such temperatures are conducive to life in certain places during certain times, but there are also extreme variations throughout the day. Temperatures also decrease very quickly with elevation, getting much lower just a few inches above the ground. Due to these surface and climate characteristics, water, though plentiful on Mars, is either frozen solid or turns into water vapour (a process called sublimation) instead of melting.

#3. Lethal Radiation Levels

NASA

The average person might not give too much thought to Earth’s magnetic field, but it is actually one of the many things which keeps us alive by deflecting much of the harmful cosmic radiation from space. Mars has lost its magnetosphere due to the fact that its core is no longer active enough. Because of this, lethal cosmic radiation constantly bombards the surface. Due to the lack of an ozone layer, there is no protection against ultraviolet radiation either, so your sunblock is probably not going to be very effective. These factors combined mean that almost no known form of life can thrive on the surface, although this may not be the case underneath the soil. The Curiosity Rover is currently examining this possibility.

#4. Limited Water Activity

NASA

Water on Mars is now known to be abundant, although it is only found in the form of ice and trace amounts of water vapour. In November, 2016, NASA even discovered a huge underground ice deposit beneath Utopia Planitia. However, long ago, Mars likely had oceans on its surface much like those of Earth. Today, the only water activity that occurs is the occasional sublimation of ice into water vapour when temperatures permit. With no water activity, there is no rain. All you will find on the lifeless desert surface is frost in some areas, sub-surface ice, and large amounts of permafrost in shaded areas. If you drop a bucket of water onto the surface, it will boil away almost immediately or turn to snow, depending on the temperature.

#5. Fearsome Dust Storms

NASA

Mars is perhaps not completely dead, at least in terms of there not being any kind of activity there at all. Just like Earth, Mars has wind, but its effects would be relatively minimal compared to similar wind speeds on Earth, owing to the lack of air pressure. The Red Planet also boasts the largest dust storms in the Solar System. In extreme cases, these storms can cover the whole planet, shrouding much of the surface in darkness for days at a time. Dust storms on Mars typically occur when temperatures are higher. These dust storms are often so enormous that they cause drastic changes in the climate and temperature while they are active. This would have a devastating effect on the majority of Earth-like life.

#6. No Large Moons

NASA

Actually, Mars has two natural satellites, though these are both very small and irregularly-shaped, due to the fact that they don’t even have enough gravity to pull them into a sphere. For us here on Earth, the Moon has played a critical part in the evolution of life. Lunar tides continue to play an important role. The Moon helps to protect the planet by dragging away many potentially deadly asteroids thanks to its significant gravitational pull. It is also this gravitational pull that’s responsible for the lunar tides, a crucial factor in the evolution of aquatic life and life’s migration to land aeons ago. The moons of Mars, named Phobos and Deimos, are only 22.2 and 12.6 kilometres across respectively, making them rather ineffectual.

#7. No Breathable Air

NASA

Humans, as well as almost all other life forms on Earth, are fairly picky when it comes to what they breathe. Our atmosphere is roughly 78% nitrogen and 21% oxygen. Mars’s atmosphere is 95% carbon dioxide, and it is a great deal thinner as well. In fact, the Martian atmosphere is almost comparable a laboratory vacuum. There is oxygen on Mars, but only in trace amounts along with other gasses such as argon and nitrogen. Mars may have had a far more favourable atmosphere in its past, but as it is now, it is little more than a vacuum as far as breathing is concerned. Nonetheless, the lack of oxygen itself doesn’t necessarily preclude life: microbial life existed on Earth for billions of years without an oxygenated atmosphere.

#8. Low Gravity

NASA

Mars has a far smaller size, mass and density than Earth, which translates into a lower gravitational pull. On Mars, you would weigh only 37.5% of what you weigh on Earth. While this doesn’t present a significant danger to humans and most other organisms in the short term, it would have an enormous influence on evolution. Additionally, the long-term effects of such low gravity on the human body, though uncertain, would likely be problematic. The biggest problem with a low gravity planet with regards to life, however, is that it isn’t very conducive to holding onto a suitable atmosphere. Mars’s gravity doesn’t entirely preclude the existence of past life on the planet, but it appears to spell problems for the development of advanced organisms.

#9. Minimal Geological Activity

NASA

Geological activity has played an essential part in the evolution of life on Earth right from the very beginning. While things like earthquakes and volcanoes might not sound very life-friendly, geological activity also gives us plate tectonics, surface heating and our critical magnetosphere. By contrast, Mars has minimal geological activity. This was certainly not always the case, however. Long ago, Mars was far more active than it is today. After all, it is home to Olympus Mons, the largest volcano in the Solar System at some three times the height of Mount Everest. Today, it is generally believed that there is no volcanic activity on Mars, and plate tectonics are negligible and perhaps even completely non-existent.

#10. Forward Contamination

NASA

Perhaps the most interesting of all possibilities is the prospect of forward contamination, in which we ourselves may have killed off any life that once lived on the surface. With all the man-made objects being sent to the planet over the past few decades, there is a possibility that some microorganisms could have hitched a ride. These may contaminate any possible biosphere that Mars may have. Although it is highly unlikely that any kind of life has existed on Mars in recent aeons, forward contamination could end up wiping it out, if it hasn’t already. Consider for example, the devastating effects which Western diseases had on local populations when the Europeans colonized the Americas.