Mars Exploration
The curious case of mars
By Pauline Yakubovich
As we build more advanced technology, we will have the capability to uncover the deepest secrets of the universe, and our newest scientific discoveries will be out of this world, literally. Last year, with the launch of the Perseverance rover, the world turned its attention to Mars, Earth’s red neighbor, and now that the Curiosity and Perseverance rovers are exploring the surface of Mars, scientists are quickly learning about the biochemical makeup of the red planet’s surface. Through the Curiosity rover, scientists already found the presence of sulfur, nitrogen, oxygen, phosphorus, and carbon, the building blocks of life, but they are investigating even further to see if Mars is a viable option for human life. While Curiosity found that parts of Mars could have supported life, Perseverance will look for evidence of actual life, and its scientific discoveries will leave us all to marvel. So far, the rovers have used groundbreaking technology to uncover climate patterns, quantify precipitation, investigate seismic activity, and explore the creations of magnetic fields.
Figure 1: Jezero Crater on Mars (nasa.gov)
Figure 2: Location of Jezero Crater on Mars (nasa.gov)
The rovers are focusing their research on the Jezero crater, as seen in the figure to the left, which is the best place to look for signs of ancient life as it contains a lot of the building blocks for life. Armed with cameras, sensors, x-rays, ground penetrating radar, a spectrophotometer, and a chemical composition camera, Perseverance is collecting rock core and soil samples to identify signs of past life. The rover has four main objectives: geology, astrobiology, sample caching, and preparing for humans. Firstly, the rover aims to study the rocks, soil, and overall landscape of Mars to reveal its geological history, and then it will collect these soil samples to bring back to Earth for further study. Further, it will look for signs of ancient life itself by detecting biological processes, such as the production of organic material. Lastly, the rovers will test technology that will help humans survive on Mars in preparation for human arrival.
Through all their testing of rocks and soil, Martian rovers have gathered new evidence of a wet climate on Mars. On the slopes of Mount Sharp, the Curiosity rover has detected differing soils that are likely the result of changing climate pattern, which can be seen in the image below. According to researchers at the Institute of Astrophysics in Lyon, the mountain first has areas of lake-deposited clays that indicate wet geography, and then the soil transitions into arid dunes that lacked all moisture. Moreover, at the top of the mountain, the rovers found brittle bed deposits like that of river floodplains, again indicating a transition to a wetter climate. Overall, using the ChemCam, researchers concluded that the Martian climate alternated between dry and wetter periods, before drying up completely about 3 billion years ago. Moreover, scientists are coupling climate models with the findings of the rovers to quantify the amount of snowfall and rain on Mars billions of years ago, further solidifying the discovery that there was liquid water on Mars at one point. According to researchers at the University of Texas at Austin, between 4 and 159 meters of precipitation must have fallen at once to fill the lakes and basins the rovers discovered. The existence of riverbeds and paleolakes themselves indicated to geologists that there was significant water on the surface of Mars, but this is the first time that scientists have actually been able to quantify the amount.
Figure 3: Curiosity on the Slopes of Mount Sharp (nasa.gov)
Researchers have not only uncovered climate patterns and precipitation on Mars, but they have also investigated seismic activity on the red planet. In April of 2021, the new Perseverance rover detected magnitude 3.3 and 3.1 temblors, which originated in a region called Cerberus Fossae, as seen in the image to the right. Although previous rovers have identified “marsquakes” before, the persistent appearance of temblors supports the idea that Mars is seismically active, and now scientists are aiming to discover whether these Earthquakes are more akin to those on Earth or the moon. According to NASA’s Mars exploration program, Earthquake waves tend to penetrate directly through the planet while moonquakes are scattered throughout the interior. Studying seismic activity on Mars will help us better understand Mars’ mantle and core and determine how similar living conditions on Mars are to Earth. So far, scientists have not discovered evidence of tectonic plates, but they have noted volcanically active regions, such as Cerberus Fossae, that seem to be the cause of many marsquakes.
Figure 4: Seismic fault as a result of a marsquake (nasa.gov)
Figure 5: Rover technology used to identify and record strength of marsquakes (nasa.gov)
As researchers dove deeper into these volcanic regions, they discovered that magnetic fields on the red planet existed for a much longer period of time than previously thought. A magnetic field is created by a dynamo, which is the production of an electric current from the flow of molten lava in a planet’s core. As this lava cools and solidifies in the presence of a magnetic field, minerals align themselves with the magnetic field, so by dating these rocks, scientists can discover the precise time the dynamo was active. Although Mars’ dynamo existed between 4.5 and 3.7 billion years ago and is now extinct, scientists are eager to know the precise timing because it helps them understand the planet’s evolution. They can learn about the thermal history, exactly how Mars formed, what makes it unique from other planets, and how its formation is likely to continue.
Overall, with the help of robots and rovers on Mars, researchers have made groundbreaking recent discoveries about the geology, climate, seismic activity, and magnetic fields of the red planet. Scientists have uncovered changing climate patters from soil samples and quantified the rainfall from giant storms with the help of climate models. They have studied marsquakes and identified the source of this seismic activity while also establishing the duration of magnetic fields by dating rocks. Although their ultimate goal is to look for signs of ancient life on Mars and determine if the planet is capable of housing humans, scientists have already made great strides in discovering the secrets of the red planet.