There are 9 planets and thousands of dwarf planets in the solar system we live in. But all we hear about mars. Why? The scientists are interested in Mars more than anything else in this universe.
Mars is the 4th planet and 2nd smallest planet in the solar system. It was named after the Roman god of war. Due to the iron oxide prevalent the planet has a reddish appearance. Which is distinctive among other astronomical objects and easy to spot. Mars has the largest known volcano in the solar system.
Because the rotational period as well as the tilt of the rotational axis relative to the ecliptic plane are similar to earth’s, the days and seasons are comparable to those of Earth. The tilt of the earth’s rotational axis is 23.5 degrees while the Mar’s is 25 degrees. And the mars rotational period is 1day and 37 minutes while earth’s 1 day. Now you know the similarities between earth and mars.
The scientists are interested in the possibility of life on the Mars. even though no proof of life is discovered yet. These speculations led to the mars missions. Mars-1 was the first mars mission launched in 1962. But it was not successful as the communication was lost on the way. Mars-2 and Mars-3 had found the information on Mars’s surface such as surface density of the soil, its thermal conductivity, and thermal anomalies detected on the surface.
The Viking missions in the mid-seventies carried out the first chemical analysis of Martian soil, as well as four biology experiments to detect biological activity. The experiments did not yield any conclusive evidence of life.
In the early 1980s, scientists hypothesized, based on mineralogical composition and rock texture of the surface, that certain meteorites might have a source region in Mars, in contrast to the asteroid belt. In 1984, a study showed that the isotopic composition of rare gases (Xenon, Krypton, Neon and Argon) matched the isotopic ratios of the Martian atmosphere measured by the Viking spacecraft. This discovery provided a way for geo-chemists to study Martian samples which provided a huge boost to our understanding of the geo-chemical evolution of Mars.
Until the 20th century Mars was considered a dry planet. But in 2001 when the Gamma Ray Spectrometer on board the Mars Odyssey spacecraft detected a fascinating hydrogen signature that seemed to indicate the presence of water ice. To test for the presence of water, NASA sent a spacecraft to Mars to land near the South Pole in 2007. The spacecraft studied the soil around the lander with its robotic arm and was able to establish, without any doubt, the presence of water on Mars for the first time.
In 2011 the Curiosity Rover was launched to Mars with the goal of investigation of the Martian climate and geology, assessment of whether the selected field site inside Gale has ever offered environmental conditions favorable for microbial life (including investigation of the role of water), and planetary habitability studies in preparation for human exploration. The rover is still operational, and as of April 12, 2021, Curiosity has been active on Mars for 3171 total days; 8 years, 249 days since its landing.
The Curiosity rover carries an instrument called SAM (or Sample Analysis at Mars), which contains a suite of spectrometers with the goal of detecting organic compounds on Mars. SAM has a mass spectrometer that can measure not just the elements, but the isotopes as well. This instrument has discovered large chain organic compounds on Mars. Though how these compounds formed is still a mystery.
The newest Mars expedition machine is the Perseverance. It had landed on Mars February 18th 2021. The site where Perseverance is expected to land is the place where experts believe 3.5 billion years ago held a lake filled with water and flowing rivers. It is an ideal place to search for the residues of microbial life, test new technologies, and lay the groundwork for human exploration down the road
Why Mars is so fascinating to scientist?
With above reasons scientists believe that the life could have evolved on Mars. It can be reached in 6 ½ months. Which makes Mars is the only planet that humans can visit or inhabit in the long term. The surface temperature is -630c. But it is better than the 4000c which is the surface temperature of Venus. And the planets in the outer solar system are made of gas. Which makes quite hard to land on those, let alone habitation.