Voyage
to
Mars
Introduction to Mars
Introduction to Mars
Mars has piqued our curiosity for centuries. The fourth planet from the Sun is one of the more accessible planets to study and send spacecraft to, yet there are still many mysteries surrounding the Red Planet. What happened to the water that once existed on Mars? What resources does Mars have to offer? And, of course, perhaps the most thought provoking question, has there ever been life on Mars?
In August 1996, a team of scientists at NASA Johnson Space Center and at Stanford University announced the finding of a Mars meteorite found in Antarctica that could possibly contain bacterial fossils. No definitive conclusions about Martian life were made from the meteorite, but imagine the excitement at . the concept that there could be life on another planet. People's imagination about life on Mars was sparked in 1877 when Italian astronomer Giovanni Schiaparelli announced that there were "canali" on Mars. "Canali" means "channels," in Italian, but the word was translated into English as "canals," implying that an intelligent civilization was responsible for having built the canals.
While Europe and America became fixated on the possibilities of Martian life, astronomer Percival Lowell, whose first love had always been the Red Planet, became enthralled. When Schiaparelli eyesight started to fail and he stopped observing Mars, Lowell vowed to continue the work. He drew elaborate maps of the surface of Mars showing an intricate network of canals that carried water from the melting polar caps to the drier equatorial regions. Lowell's beliefs were disproven in 1965 when the Mariner Spacecraft flew by Mars and took pictures. The pictures showed no signs of life or canals and portrayed an atmosphere that seemed much too thin to support life.
Another Mars alarm occurred on Halloween in1938 when Orson Wells narrated a science fiction story "The War of the Worlds,"' by H.G. Wells on the radio. The story described an invasion of Earth by Martians who possessed advanced technology. Millions of listeners, not recognizing the story as fiction, believed Earth was being invaded by Martians.
Over the years, a large amount of scientific data has been collected from Mars. This data has brought us closer to knowing the true nature of the Red Planet and whether or not life as we know it could have existed there. Although the cold, dry conditions on Mars may not support life now, scientists believe that Mars was warmer, wetter, and had a much denser atmosphere early in its history. Life may have existed in ancient Martian lakes or springs. If so, fossil evidence of life might be found.
Of all the planets in our Solar System, besides Earth, we have found Mars to be the most Earthlike. The rocky planet has a thin atmosphere, weather, seasons, and a day that is 24 hours and 37 minutes long. Like Earth, Mars even has two polar ice caps. Mars has a diverse and complex surface that is similar to Earth. The landscape shows unmistakable signs of past water flows over the surface, from branching networks of river channels to islands to great gouges caused by catastrophic flooding, but the liquid water seems to have disappeared. In June 2000, scientists analyzing imaging data from the Mars Global Surveyor came upon a very exciting discovery. They found areas on the surface of Mars that look like recently formed gullies. Dr. Michael Malin, principal investigator for the Mars Orbiter Camera on the Mars Global Surveyor states that, "The features are so young that they might still be forming today. We think we are seeing evidence of a ground water supply." If liquid water does exist just under the surface of Mars , it could lead to the answer to several exciting questions. For. example: could primitive life, similar to that on the Earth, exist on Mars? Is there a source of useable water for future settlements on Mars?
A source of water on Mars would alleviate one of the main problems associated with a long term settlement on Mars, the need to have enough water on Mars for people living there to survive for a long period of time. If a person is to drink about 8 cups of water a day (half a gallon), over 100 gallons would be needed for the seven to eight month trip to Mars. Additional water would be needed for the time spent there and on the return trip. If water can be extracted from anywhere on Mars whether it be the atmosphere or the ground, it would have to be used to drink, grow plants, and broken down to use the hydrogen to make rocket fuel.
In trying to figure out what happened to the water on Mars, scientists study the planet's geology and climatic history. Because there is little atmosphere and no water in liquid form on Mars, there is little erosion. This, coupled with the fact that Mars has no plate tectonics, means that the Martian surface is like a book tl1at has recorded the planet's entire history. We want to know what happened to the water on Mars, because Mars and Earth started out very much alike. Could what happened to the water on Mars happen to Earth someday?
Geologic features lead to more unanswered questions. While Mars is one of the smaller rocky planets-its diameter half the size of Earth's-some features on Mars are enormous. Olympus Mons (27 km. tall) is the largest known volcano in the Solar System; Valles Marineris is an enormous canyon system that would stretch across the continental United States. Mars seems to have a solid crust-not broken up into multiple plates-with very little movement at the surface.
We will probably see a human mission to Mars in our lifetime, but until we are fully prepared to send humans, NASA will continue with its robotic mission.,. VIking 1 and VIking 2, each consisting of an orbiter and a lander, launched in 1975 and sent pictures and other information a year later. The Mars Pathfinder Mission was launched in December 1996. The Pathfinder returned a wealth of information, including more than 16,000 images from a lander and 550 images from a rover. The Mars Global Surveyor program has been sending back high resolution images since it went into orbit around Mars in September 1997. The next generation of spacecraft, the Mars Surveyor program, will include an orbiter to carry out remote surface exploration and global studies. It may also include a rover and sample return vehicle.
While information continues to be acquired from the robotic missions to Mars, there are scientists and engineers designing new equipment for traveling to and living on Mars. One new technology being studied is the design of a plasma rocket. A plasma rocket would use gases heated to temperatures high enough to tear the electrons off of atoms. The atoms are then propelled by magnetic fields. A working plasma rocket could cut the travel time to Mars from seven or eight months to slightly over three months.
The continuing Mars missions and research by engineers and scientists will allow people, instead of robots, to eventually live on and explore Mars.
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Support for program number HST-ED-90285.01-A was provided by NASA through a grant from the Space Telescope Science Institute, which is operated by the Association of Universities for Research in Astronomy, Incorporated, under NASA contract NAS5-26555. Copyright (c) 2007 Challenger Learning Center at Prairie Aviation Museum and Challenger Learning Center of Northwest Indiana. Staff of Challenger Learning Centers and instructors of classes involved with Challenger Learning Center missions may reproduce this WebQuest guide for classroom and educational purposes. Otherwise this work may not be reproduced, stored in a retrieval system, or transcribed, in any form or by means – electronic, mechanical, photocopying, recording, or otherwise – without the prior written permission of the copyright owners. This page is based upon the WebQuest model. |