Goals of the twin rovers
We shall now see the goals of these rovers.
Is Mars safe for man to visit?
Taking into account man's fascination with Mars, there is no question about the fact that man may one day visit Mars.
As we said earlier, there are many conditions in Mars which makes it unsuitable for human exploration and to overcome this we need to study the conditions in Mars.
Mars lacks an ozone layer. Because of this we are not protected from ultraviolet radiation from the sun. Also Mars, having no magnetic field, is unable to ward of cosmic radiation as in case of earth. The MERs will make a study of the amount of radiation in the Martian environment so that suitable spacesuits are designed for the astronauts.
The previous explorations in Mars have revealed the presence of superoxides. These, on exposure to ultraviolet radiation break up organic molecules. The effect of this on humans is not known for sure. Also, many other dangers of the chemicals in Mars is unknown. The MERS will make a detailed study of the mineralogy of Martian surface. This may also reveal to us how the resources can be tapped to produce materials that aid human stay.
Also we need to study the characteristics of Martian soil (how soft is the soil? etc) so that no problems are caused during human exploration program.
These rovers along with the Mars Reconnaissance Orbiter (future mission) will search for existence of water on Mars.
Data about the gravitational forces on Mars and the nature of Martian surface could help us design soft landers for human descent.
Thus these missions will eventually make man ready for a mission to Mars.
To determine if life ever existed on Mars
The MERs do not have the capability to detect life on Mars directly. But it checks for presence out those geological factors that are intricately woven into existence of life.
One of these factors is water. Now, rather than searching for actual water, the MERs check for possibility of existence of stable water on Mars anytime in the history of the planet. Studying the soil and rocks of this planet will reveal whether water is associated with the rock formation in Mars.
Data from Mars Global Surveyor suggest that liquid water may exist just below the surface in rare places on the planet. Also it has been found that water exists in form of ice at the Martian poles.
Life also needs energy for survival. So, future missions will search for energy resources on Mars other than the sun. The superoxides on Martian surface (as discussed in humans on Mars) break down organic matter. This prevents life on Mars. If life is present on Mars it could very well be due to other energy sources. For example chemical and geothermal energy as used by some microbes on earth.
Another way to determine if life ever existed on Mars is to check for telltale marks of life. For example, in earth, fossils are formed. Searches are on for presence of those conditions on Mars which could assist in formation of fossils. Eventually, if such places are found, searches would continue for fossils.
The theory of existence of life on Mars is not based just on wild imaginations. Years ago, people did speculate. But it was no longer a hypothesis when a meteorite from Mars, found in 1984 in Antarctica , had evidence for fossil life. The images of structures in the carbonate globules that look like the extremely tiny, nano-bacteria recently detected in Earth rocks.
But it is not necessary that the sign of existence of life on Mars would be same as that of earth. It is even not necessary that the life on Mars is made up of carbon as we are or that they can survive only with presence of water.
There could very well be species that survive on carbon dioxide and do not consume the “poisonous substances called water and oxygen”. So the trick is to differentiate the ‘non-life' matter from ‘life'.
Many life detection technologies are under study. These technologies unlike the present day ones, view ‘life' as ‘life' alone and not as ‘life' put in the ‘frame' of earth. These technologies in future could help us determine various forms of life, different from those on earth.
Climate of Mars
The structure of the rocks and the way their weathering has taken place can tell us the past climate of Mars. As explained in the section of rover science instruments, various instruments determine the composition of soil and rocks not only on the surface of Mars (which determines the climate in past few years) but also the composition under the surface (which gives the history). One instrument is also used to gather temperature profiles of the atmospheric boundary layer - the layer of atmosphere from the surface up to 10 kilometers in altitude. This provides information for understanding the current climate on Mars.
There are seasonal changes in Mars. The most important one is the change in the carbon dioxide ice caps . Also the dust storms that occur in the southern spring and summer are being studied.
Monitoring the planet for this information over one full Martian year (687 Earth days) will help us understand how Mars behaves over its seasonal cycle and guide us toward understanding how the planet changes over millions of years.
Geology of Mars
The rover's scientific instruments enable the rover to perform all kind of operations on the surface of Mars. (see rovers science instruments)
As explained in science instruments, a detailed mineralogical study of the planets surface would be carried out. The rock abrasion tool would enable us to fine the properties of rocks underneath the thick Martian dust layer.
The limelight would be on the compounds containing iron as iron reacts strongly with water. It is necessary to determine whether the reddish soil is a result of oxidizing property of atmosphere or due to water.
A search for rocks and soils that hold clues to past water activity (water-bearing minerals like clays and carbonates and minerals deposited by precipitation, evaporation, sedimentary cementation, or hydrothermal activity).
Also the materials trapped in these rocks throw light on the planets past.
The determination of the spatial distribution and composition of minerals, rocks and soils surrounding the landing sites is also on the agenda.
The nature of local surface geologic processes would be determined from surface morphology and chemistry.
The mission also determines what forces have shaped the landscape of Mars. Was it wind, water, volcanism, meteorite impacts etc? it also studies how the present landscape was created.
Magnetic Field of Mars in the past
The large amount of magnetic material on Mars shows that the planet once had a magnetic field, much like Earth does today.
We have already stated that magnetic fields shield planets from many forms of cosmic radiation. As Mars does not have such a magnetic field, cosmic radiation is present in large amounts in its atmosphere.
Study of the ancient magnetic field also provides important information about the interior structure, temperature and composition of Mars in the past.
What the Rover's cannot do?
After the entire section of goals, in order to remove misinterpretations, let us tell you what the rovers are NOT designed to do: