Mars is a world we have always observed from historic periods. Its movement, phases, and geographical land influenced our understanding of outer planets, and even the movement of the planet has improved our understanding of the structure of our solar system and the orbit of planets. When humans started to search for other habitable zones for humans or other life forms in the solar system, the first consideration was the rocky planets – Mercury, Venus, and Mars. Mars has a similar world that has a solid crust and layered interior but has different surface conditions. Venus, even though called earth’s twin, is a hellish hot world under a dense acidic atmosphere. Mercury is an airless ball of baking rock. Comparing these with our planet, Earth, a planet with moderate temperature and plenty of water even though small, cold and dry, Mars is the earth-like planet in the solar system.
Does Mars have the same magnetic field and interior as earth?
The interior of mars always left humans with questions. Earlier, we expected the planet to have a strong magnetic field like that of earth. To our surprise, now the planet lacks or has a weak magnetic field, but the surface rock preserves evidence of a magnetic field. Scientists have been trying to answer the question and to study more about the core. The first theories proposed that Mars had a core like that of earth and faded away as the core cooled and solidified. However, the geodetic measurements were suggested differently. The tides on Mars pointed to a liquid core. The present atmosphere of Mars is thin and unable to withstand the running water, but scientists have already found evidence of the past presence of lakes, and oceans, which made the scientific world find the reason for the eroding atmosphere of Mars. Experiments were done to understand these changes; in one of them, the scientist stimulated the early martian core by using a sample containing materials like iron, sulphur and hydrogen, which were expected to be present in early martian conditions and compressed the same between two diamonds to create an immense pressure and temperature similar to that of the early martian core. The result was the sample material formed two liquids – one of the iron liquid rich in sulphur and the other rich in hydrogen. Further in the experiment, the less dense hydrogen-rich liquid rises above the denser sulphur-rich liquid, which must be the reason for the early magnetic field resulting from the convection of this process. As the full liquid layer rises above, gradually, the magnetic field fades away. As the magnetic start to fade away, the solar wind, the stream of charged particles emitting from the sun, which carry the sun’s magnetic field, blows away the atmosphere. The lesser environment leads to the breaking down of hydrogen and the present state of the planet. In truth, Mars died billions of years ago, according to our definition of habitability. We are still searching for evidence if any life form originated in the past.
How many phases does the planet Mars have before reaching the present stage?
Mars originated as a ball of molten rock 4.5 billion years ago. The history of Mars is divided into four phases according to geological activity. Each period is with reference to major features at that time. The time period and history details change as new details are obtained. The first period is called the Pre-Noachian period dating back to the formation of the planet around 4.5 billion years ago. This period is marked by heavy bombardment from outer space and volcanic activity, while volcanism led to the formation of a thick atmosphere which allowed the cooling of water. Most of the features of this age had destroyed or eroded, but the most prominent one is the – crustal dichotomy – the difference between the elevated, heavily cratered southern highlands and the smoother flattened northern hemisphere. The caters record is proof the southern hemisphere was exposed to the Late Heavy Bombardment period around 4 billion years – while it’s still molten, the northern hemisphere remains unaffected. The next phase of Mars is known as the Noachis period, named after the Noachis Terra region of the southern highland, which lasted from 4.1 to 3.7 billion years. This was period marked by major impacts during Late Heavy Bombardment. The Hellas, Isidis and Argyre basins, the largest impact structures still visible on the planet’s surface, are evidence of these bombardments. It was also marked by heavy volcanic activity and likely the presence of large amounts of water, which formed standing bodies, and river channels. The trace of river and water bodies can be traced back to this period. The next phase of martian evolution is known as Hesperian, named after Hesperia Planum, dated between 3 billion and 3.7 billion years ago, a lava plain in the southern hemisphere. This is the period in which Olympus Mons probably started to form on the pre-existing Tharsis rise. This period is marked by volcanic activity, widespread volcanic planes were there, and almost 30 per cent of mars resurfaced during this phase. This was a period of radical climate change which is closely related to the gradual loss of atmosphere ( the most prominent and accepted reason is the solar wind, some other theories are by ejection to outer space due to one or more asteroid impact ), which result in transient standing bodies and water in the martian surface either froze or withdraw to underground, from where it emerges during occasional catastrophic floods that left huge scars in the surface. The next or the last phase is the Amazonian, dated from 3 billion years ago to the present time. It is named after Amazonis Planitia, the lowland lava plain between Tharsis and Elysium volcanic region, the smoothest surface on the Martian surface. During this period, the geological activities and climate change became less, the planet remained arid, weathering of rocks occurred, and an extensive resurfacing of northern lowlands. The erosion and deposition lead to the formation of sand dunes, which cover or destroy old terrains. The glaciers played a major role in shaping the martian surface. The surface alteration by the formation of anhydrous ferric oxides led to the planet’s characteristic red colour.
Is Mars the next giant leap for Humanity?
In the history of space exploration, the human race is always in research of the next home apart from the earth. During this journey, the moon and then Mars was always considered as the next home. Mars exploration missions started in the 1960s by the USSR, followed by the U.S. The first Mars missions were a failure; the first successful flyby was done by NASA’s Mariner 4 on 28 November 1964.
The journey to mars had been tough for the soviet union with a number of failed attempts, but on December 2, 1971, USSR’s Mars 3 landed successfully on Mars’s surface even though it only worked for 15 to 20 seconds; considering how hard the mars landing is, it made a soft landing and opened the television camera.
Still, the world has to wait for NASA’s Viking -1 and other rovers to find out the science and to get photos of the Martian surface.
On 24th September 2014, India’s Mars Orbiter Mission (MOM), also known as Mangalyan, entered Mars orbit. India is the first country to make it to mars orbit in the first mission and only the fourth country to do so.
Now more countries have made their first attempts, and more missions are targeted towards mars. Even Nasa flew Ingenuity, a small helicopter on Mars and planned to send humans by the end of the 2030s.