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Compare-Contrast-Connect: Water on Mars

Andrea J. P. Jones, Education and Public Outreach (EPO) Specialist with the Lunar and Planetary Institute and NASA Goddard Space Flight Center.    Photo courtesy of NASA/JPL-CaltechSF. 5-1. Mars, the fourth planet from the sun in our solar system.
Although earth has the most liquid water in the solar system, water is also found on other planets and moons. Scientists are very interested in water because life as we know it requires this important molecule. Earth is the only planet in our solar system where we know multi-cellular life exists.  All life on earth depends on water, and all living things on earth contain water. Because of this, the search for life beyond earth often begins as a search for water.
Mars is one of the places space agencies such as NASA (National Aeronautics and Space Administration) have been looking for water. As early as the seventeenth century, astronomers observing Mars through telescopes saw white features at its north and south poles. Speculations arose about whether these features were water ice polar caps, like we have on earth. Some astronomers thought they saw channels on the Martian surface. At the turn of the 20th century, one astronomer, Percival Lowell, spent his career trying to convince the world that the straight lines he mapped crisscrossing the Red Planet were not just channels, but canals built by a technologically advanced Martian civilization distributing water around its drying planet. Debates about the origin of the canals of Mars and if Mars had water persisted through the first half of the twentieth Century, until spacecraft observations settled the controversy.     Photo courtesy of NASA/JPL-Caltech/University of ArizonaSF. 5-2. Channels on Mars
The earliest spacecraft images of mars revealed a dry, desolate, heavily cratered world not unlike our moon. But starting with the Mariner 9 spacecraft that imaged mars in 1971, a new world was revealed with rich history of water recorded on its surface. Mars has intricate networks of drainage channels, some which may have been carved by rain. Thick layers of dusty ice deposits cap the poles, and recent impacts at lower latitudes have exposed water ice hiding just below the rocky surface. Mars shows evidence of floods a hundred times larger than the largest floods we know of on Earth. There is evidence that there were once lakes in some Martian craters, and some scientists even believe that a vast ocean once covered much of its northern hemisphere. To test the hypothesis that water ice exists on mars, a mission was sent to the high northern latitudes to investigate. The Phoenix Mars Lander confirmed the evidence and chemically proved, using a mass spectrometer that water exists on mars.
NASA’s is still looking for more traces of water on mars, and learning more about the history of water on the planet, but investigations are also incorporating a new purpose: “Seeking Signs of Life.” Now we want to understand the habitability of Mars, past and present. Has any life taken advantage of the water on our neighboring planet? Is it life on the planet today? And, if not, why not? A new mission that will start exploring the Martian surface in 2012, the Mars Science Laboratory Curiosity rover, will help answer those questions.


Question Set: 
  1. What is a mass spectrometer?  How can it be used to prove the existence of water?
  2. Where did the water on mars go?  Research current hypothesizes about why there is no longer any large amounts of liquid water on the surface of mars.

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Exploring Our Fluid Earth, a product of the Curriculum Research & Development Group (CRDG), College of Education. University of Hawaii, 2011. This document may be freely reproduced and distributed for non-profit educational purposes.