The Red Planet
A journey through Mars.
Note to the reader: I enjoy reading and writing about astronomy. It soothes me, and it baffles me every time I read something on the subject. I reckon there are other people like myself, and thus, I compiled the notes for this article into a document. If you are fond of it, dear reader, you are more than welcome to read it, and contribute to it. Visit this link if you want to read the notes. The references I used, are also there.
Ancient Rome, had a protector. Only second to Jupiter (his farther), he was known for the dignity of his character. Roughly translated to “martial” in English, the Latin word — Mars — fit him perfectly, for he was later dignified as the Roman God of War. Red was his color, and the wolf (which is the symbol of Rome) was his animal. Ancient Romans, upon looking at the night sky, saw a planet— reddish in appearance — and thought it looked familiar, and named it after their God of War who preferred the same color. It was not only the Romans who thought the same way: Egyptians named the planet “Her Desher”, giving it the meaning “the red one”.
Mars is one of the closest planets to the Earth, and hence one of the most visible ones in the night sky. Mars plays host to large sand dunes, enormous mountains and across those mountains flow swift winds almost as fast as half of the speed of sound. These winds carve different patterns in the sand: some look like Pyramids, some look like rivers — which Percival Lowell famously mistook as evidence for the existence of dying agricultural beings on Mars, and the like. Mars also has polar ice caps just like we have here on Earth. Mars shares the same 24-hour a day time frame (a little more than 24). There are large impact craters on Mars which gives evidence for collateral collisions with meteorites. Mars, is a planet much like ours, but without one very important entity — complex life.
Martian Breath and Martian Floor
Martian Breath
Martian air is 95% CO₂. 30% of these CO₂ is in solid forms in the polar caps. Mars lacks a properly-built magnetosphere (magnetic field) to keep the solar wind away from the planet, and thus, the solar flares rip apart the molecules. Precisely because of this, the CO₂ and O₂ are constantly broken down into their atomic counterparts (CO, and O). The very same fact makes an ozone layer implausible. Martian atmosphere is incredibly thin (i.e. small number of air molecules per a volume), because of lower gravity and the exposure to solar wind pushes air out from the atmosphere into space. Mechanisms like Jean’s Escape (temperature variations giving the molecules escape velocity to escape gravity), Photochemical Loss (photochemical elements performing exothermic reactions giving molecules the energy to escape gravity), Iron Loss (ionized molecules carrying into space by the solar wind) and Sputtering (solar wind “knocking” air molecules into space) make the atmosphere thinner and thinner in time, given that there is no known mechanism internally to create molecules. Because of the lightweight air column in Mars, the pressure is only 1% of that of the Earth! This incredibly thin atmosphere makes the formation of a Greenhouse Effect implausible, and therefore, the temperatures plummet down in Mars to an average of about -63 degrees Celsius (Earth’s average is about +15 degrees Celsius)
Observations detected trace amounts of Methane (CH₄), to everyone’s surprise, since the source of Methane in Mars is currently unknown. On Earth, the primary sources of CH₄ are human-activities and livestock, mixed with natural sources such as wetlands. Are there agricultural Martians we never knew about?
Martian Floor
The rapid and swift winds of Mars are mainly due to thermal differences in different areas. When air gets warm, they expand and flow upward (like a balloon). This leads to lower pressure at altitude, and these warmer air pockets are pushed by force towards low pressure regions which are cooler.
The landscape of the Martian surface is largely sculpted by these winds. However, even though there are speedy winds in Mars, the air is very thin. Thus, the winds on Mars are only capable of bothering grains of micrometer-size. How does this thin airflow carve such amazing sand dunes we observe on Mars?
There are two interpretations for this: either what we see can be the dunes sculpted by the winds of thousands of years. Or, the winds can lift up some sand grains, and when they hit the ground they would eject more grains. This phenomenon, in literature, is called Saltation. It is suggested that large sand dunes such as Meridiani Planum dune are sculpted by wind in this manner.
Our blood is red because of Iron Oxides. Mars’ shares the same source for its color. Its regolith oxidize with oxygen forms in the atmosphere and form a reddish-orange color. How did iron get combined with oxygen in a oxygen-poor atmosphere? There are many debates. Some say that it was an earlier incident, when Mars was younger, it was abundant with water and oxygen. Others say that it was a gradual process, years of oxidization with smaller amounts of oxygen in the atmosphere. Some argue that it was due to the strong winds crumbling quartz crystals in the regolith and leaving their oxygen-rich surfaces exposed.
Volcanoes
The planet’s grandest volcano are situated near Tharis region. Tharsis is not the only Martian volcanic center. There’s Elysium, Syrtis Major, and other volcanoes near the Hellas Impact Basin. These volcanoes are believed to be a source of CO₂ present in the atmosphere, and it is believed that they heated the atmosphere as well. No volcanic activity heats off the planet today. The outer crust of Mars is too thick for the molten metal in the core to be ejected out through a volcanic activity. Maybe the volcanic activities have permanently ended, or we might be seeing an inert epoch of Mars.
Olympus Mons, the largest volcano in the solar system, is 600km in diameter, and 21km in height (nearly thrice the height of Mount Everest!). The large size of the Martian volcanoes is due to the absence of plate tectonics of the planet. In the absence of tectonics, it would form one huge volcano instead of producing a series of smaller ones.
Craters
Two kinds of craters exist. Volcanic craters, created after a massive explosion of a volcano, and impact craters, which were created following a collision between the surface and a meteorite. Mars consists of 635,000 impact craters worldwide. The largest crater observed being the Huygens crater, named after Christian Huygens, the discoverer of Titan, the largest moon on Saturn. There are certain craters (volcanic) called Maar craters, which are formed by a violent reaction of volcanic magma with a steady region of groundwater. Maar craters look very much like impact craters, so it’s difficult to discern. However, identifying Maar craters is a precursor for water beneath them.
Martian River Valleys
Looking through telescopes, we see river-like carvings in the Martian surface. What are they?
Scientists have found out that once in a lively epoch on Mars, water flowed through these great river valleys. Lava and liquid carbon dioxide were also thought of as candidates, but they were refuted by evidence.The sources for water that ran on these river valleys are numerous. Hydrothermal sources, that are formed following some kind of an impact on a side of a volcano, cause magma to rise. This heats water within the sub-surface, and forms convection springs of heated water. Another source might be rain. Mars Reconnaissance Orbiter (MRO) used its spectrometer to find out traces of hydrated minerals on the narrow streaks inside the crater walls. These minerals (salts) can lower the freezing point of sub-surface liquids, including water. Therefore, it is suspected that beneath the thick walls of craters, lie rivers of groundwater.
Prospects of Martian Life
Even on Earth, there are forms of life that can endure extreme environmental conditions like high pressures and high temperatures. They find their own ways to cope up with changing surroundings, either by shelter or adapting themselves to change. If someone pushes a planetary scientist to point out where to search for life on Mars, without any doubt the scientist would answer “Look where the water is!”. Water is an essential component to life as we know it. But that is for life as we know it. Can there be Silicon-based beings, unknown to our imaginations, living beneath the rocks?
The current conditions on Mars do not permit complex life. Absence of a steady temperature, and the lack of hospitable atmosphere make life implausible at a first glance. To terraform mars, we must:
- Create an atmosphere
- Mediate the temperature
- Harbor (or transport) the necessary essentials for life.
Creating the atmosphere would require us to create sufficient greenhouse effect for plants to breath in CO₂ and breath out O₂, just like they did in primitive Earth. Temperature would be mediated if it is possible to create the aforementioned greenhouse effect, since the CO₂, CH₄ and H₂O molecules trap the heat of solar radiation. Food and water are essential for life. We must find a way to either transport goods from Earth, or to manufacture/grow the requirements on Mars. Mars’ soil is not rich for plants to grow, and thus, fertilizers and other requirements are needed to be artificially manufactured. If we can tap into the riches of underground water that scientists believe there exist today, this would help the process of terraforming.
The first two possibilities (creation and mediation of atmosphere) were investigated in a paper in 2018 by a research group led by Bruce M. Jakosky. The group considered the possibilities to harbor an environment that is habitable, by using the materials and resources available on Mars itself. They considered scenarios such as using the reservoirs of CO₂ in the polar ice caps, heating them and tapping into the CO₂ to create a greenhouse effect. Furthermore, they investigated scenarios such as using carbon-bearing minerals and oxidizing them to produce the CO₂ yield they required. Their conclusion was that using the contemporary technology that we possess today, and what we have observed in Mars up-to date, we do not have enough resources and/or Mars do not possess enough materials to create the sufficient atmospheric conditions to suit for life. Either the materials which we can use to terraform Mars have not been observed, inaccessible or not there. Another possibility they considered was increasing the atmospheric density by outgassing juvenile gasses and creating a form of an artificial magnetic field making the atmosphere resistant to the solar wind. However, a natural outgassing mechanism (e.g. volcanoes) operate at very low pace on Mars, and thus it would consume about 10 million years to create the current atmospheric mass (which is very low) in Mars even with zero loss of atmosphere to space.
Future Prospects for Mars
Given our current knowledge and abilities, we’re not yet able to terraform the world we look out for. But day by day, we keep improving. Elon Musk’s Starship is being designed to carry us into the Red Planet. It’s a long journey. It is suggested that it would take at least seven months to reach Mars. Future prospects of space travel include a “Lunar Pit” refueling station, which fuels the spacecraft with synthesized rocket-fuel from hydrogen and oxygen extracted from lunar craters. We have already sent Sojourner, Spirit, Opportunity, and Curiosity rovers to examine the planet. The new rover, Perseverance has already been launched and will land on Mars on 2021. Overcoming the challenges of shielding against radiation, lower pressure, temperature variations, climate variations and resource management would require some more time for us to be able to set foot on the Red Planet.
Mars was and is, a pop culture. Novels, songs and stories were written surrounding it. Mars stir us because it somehow reminds us of our home. It doesn’t look like our home. We look towards it because it may be our nearby hope to visit. But it seems that it had a past we don’t yet know about. We’re on our way of uncovering the mysteries bit by bit. By some incident, it was left barren, desolate and cold. We don’t yet know what happened. But, Mars displays a stark contrast of a fate that awaits us if we do not take care of our own home, the Earth. Judging by the current trends, the Earth would not look like Mars, but it would look more like Venus (a stark contrast with Mars), where a runaway greenhouse effect is at play. Nevertheless, the eventuality would be the same: a barren, desolate and dull red planet.
The difference is, Mars displays promise under the grounds and walls. The dead Earth, would seemingly not.
