Mars Astrobiology: Recent Status and Progress - Planetary Exploration and Science: Recent Results and Advances - page 143

Chapter 8
Mars Astrobiology: Recent Status and Progress

Antonio de Morais M. Teles

Abstract In this chapter, we begin making a brief review on the history of the
studies of planet Mars. Then, we review the modern research (with recent status,
data, results, and progress) on the search for possible extinct or extant life on
Mars, with special emphasis on the search for the presence (in the past and/or
presently) of liquid water within Mars' surface and subsurface - a prerequisite for
the evolution from geochemical state to biogeochemical state, as we are aware of
here on planet Earth. Through the chapter, I present some proposals of mine about
the astrobiology of Mars. We also analyze recent astrobiological experiments on
board the International Space Station (ISS) for the future exploration of Mars. And
we make a brief review on the evolution of equipment for its exploration and of
future manned presence on the beautiful planet Mars - the “Red Planet.”

Keywords Mars ￿ Astrobiology ￿ Biogeochemistry ￿ Space ￿ Planets

￿ Exploration ￿ Terraforming

8.1 Introduction: Past Search for Life on Mars

Well, for centuries, people have speculated about the possibility of life on Mars due
to the planet's proximity and similarity to Earth. Serious searches for evidence of
life began in the nineteenth century. Mars' polar ice caps were observed as early
as the mid-seventeenth century, and they were first proven to grow and shrink
alternately, in the summer and winter of each hemisphere, by William Herschel
in the latter part of the eighteenth century.
By the mid-nineteenth century, astronomers knew that Mars had certain other
similarities to Earth, for example, that the length of a day on Mars was almost the
same as a day on Earth. They also knew that its axial tilt was similar to Earth's,