Mars exploration: Why are scientists so fascinated with the Red Planet?

NASA’s Perseverance Rover that successfully landed on the surface of Mars, ready to embark on its mission to search evidence for microbial life is one of the most ambitious, expensive, sophisticated missions on Mars by the US-based space agency. This mission will set the ball rolling for the next couple of decades of Mars exploration for the search of life or even manned mission.

What has been found about Mars so far?

Since the first-generation mission in the 1960s, space scientists have come a long way in understanding Mars. The Viking mission that took place in the mid-seventies studies Martian soil and conducted biology experiment in search of signs for life but without any positive outcomes.

In the early 1980s, scientists after studying mineralogical compositions of a certain rock, meteorites that had hit earth, assumed that they might have originated from Mars and not from the asteroid belt. The isotopic composition of rare gases matched the isotopic composition of Martian atmosphere in a 1984 study giving the first lead towards understanding the geochemical evolution of Mars.

Mars was considered without any signs of water until 2001 when a Gamma-ray Spectrometer sent with the Mars Odyssey spacecraft found signs of hydrogen indicating the presence of water and ice. However, there was a scope of argument as hydrogen can be part of organic compounds as well.

In 2007, when NASA sent a spacecraft to land near the Martian South Pole, its robotic arms collect soil around it and without any doubt established that there indeed was the presence of water on Mars for the first time.

The instrument on a Curiosity Rover that studies soil samples on Mars, SAM also has a suite of spectrometers to detect organic compounds and isotopes on Mars. SAM made a fascinating discovery of a large chain of organic compounds on Mars. Although such compounds can be made through inanimate processes there is also the possibility of traces of life associated with making them.

Mars Insight, another lander is currently monitoring seismic activity and heat flow on Mars to understand the composition of the Martian interiors.

Why are scientists so fascinated with Mars?

The conditions of Mars were very similar to what it was at Earth 4 billion years ago. It too had a thick atmosphere that helped water to settle on its surface. Hence, chances of finding life on Mars are more than on any other planet.

Also the atmospheric conditions, the temperature at Mars is hospitable for long term compared to other neighbouring planets like Mercury and Venus where it is more than 400 degrees C. At Mars, the approximate range of temperature is between 20 degrees C at equator and minus 125 degrees C at poles. For the rest of the bigger planets like Jupiter, Saturn, they are made of gases and are extremely cold.

What are the goals of the Perseverance rover on Mars?

The rover will address two important things: search of signs of microbial life and can humans be sent to Mars.

The Mars soil samples that the rover will bring back will be studied in most equipped labs around the world to find a definitive answer about existence of life on mars in the past.

Perseverance will collect soil and rock samples in cigar-shaped tubes, seal the canisters and leave it there. Next the European Space Agency’s Mars Fetch Rover will collect the samples from different locations and return to the lander.

The canisters will be transferred to the Ascent Vehicle, that will meet an orbiter and the Orbiter will finally carry the samples back to the Earth. This entire process is called Mars Sample Return (MSR)

However, if one of the components of the MSR project fails, the entire process falls. The hidden risk for the three-tier, high-cost involved process is strategic and NASA had to foreclose many other space missions to carry on with MSR.

What is required for carrying a manned mission to Mars?

Oxygen is very important for a manned mission as it provides for breathing of the astronauts and fuel for the trip back to Earth. To carry a cost-effective human mission to Mars there should be a technology in place where oxygen can be produced on Mars using its atmosphere or raw material present there. Else a manned mission can be too expensive or unrealistic. Also, Elon Musk’s plan to provide commercial transportation to the planet can fail.

Perseverance’s Mars Oxygen In-Situ Resource Utilisation Experiment (MOXIE) instrument will try to produce 10 grams of oxygen by using 300 watts of power. If the experiment is successful, production of oxygen can be scaled by 100 times to support a manned mission to Mars.

The rover will also carry Mars’ Subsurface Experiment by mapping its subsurface structure to find water on Mars. If found it will be instrumental for a human mission or human settlement.

Helicopter experiment on Mars

A small drone will be made to fly on the sparse atmosphere on Mars to see if helicopters can be used for long-distance transportation on Mars. But the low density of the Martian atmosphere makes the odds very low and hence astronauts might have to rely on rocket engines for power ascent and descent.

The perseverance rover is expected to answer the two most significant questions for decades of upcoming Mars exploration: weather Mars harboured microscopic life in the past and is it atmosphere conducive to support the human mission?