Planet Mars

But scientists argued that if there had been liquid water on Mars , the atmosphere must have been much thicker , and the current atmosphere on Mars is too thin to prevent liquid water from evaporating quickly . Some or all of the water present today may be in the form of subsurface ice This is called permafrost , and similar subsurface deposits are found in arctic regions on Earth . There are regions on Mars where it appears that subsurface ice has suddenly melted , causing the surface to collapse and thus the resulting jumbled areas are called

chaotic terrain (Pollack , 1995

The search for life on Mars

Scientists observing from Earth could not establish evidence of Martian life . They explained the dark surface markings and the seasonal variations in other ways . The Viking missions conducted searches for microscopic life-forms in Martian soil samples and found no organic molecules in the soil . Although no evidence for life was found , the possibility that life once existed on Mars was not ruled out . The fact that Mars once had liquid water and a denser , warmer atmosphere suggests that primitive life-forms might once have existed there . Thus , future missions may be designed to look for fossil microorganisms (Caplinger 1995 , Conclusion section

Conclusions

The mysterious red planet is still mysterious , but in new ways . Most of the age-old questions related to its changing appearance , the possibility of civilizations thriving on its surface , and its distinctive color have been answered through close-up examination . What scientists have found is a planet like the Earth , except one not as fully developed , in the geological sense

But the interest awakened about the planet has not subsided , and , after the Moon , it will probably be the next body in the Solar System to be visited by astronauts References

Caplinger ,M (1995 , April . Life on...