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by Dr. Fred Bortz


Safesurf Rated All Ages


For more than twenty years, Dr. Fred Bortz worked as a scientist, researcher, and teacher. Now he spends most of his time writing books and articles for young readers like you.

He enjoys both science and writing for the same reason: HE LOVES QUESTIONS. He writes for people your age because he knows you love questions, too.

To find hot-links to other "Ask Dr. Fred" questions and learn how to send Dr. Fred your favorite question, go to the main "Ask Dr. Fred" page.


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"Is there life on Mars?"

For the latest updates on this question and more hot-links, including one for the latest news from the Mars rovers, click here!

Ever since astronomers discovered that the planets were other worlds, people have wondered whether life might exist on them. In the mid-nineteenth century, Italian astronomer Giovanni Schiaparelli, studying the markings on the surface of Mars, believed that he saw channels (or canali in Italian), which might have carried water. The Italian word was mistranslated into English, and many people mistakenly believed that Schiaparelli was describing canals built by Martians to transport water from the planet's polar caps to its warmer regions.

Later in that century, the famous astronomer Percival Lowell observed that the surface of Mars changed color with the planet's seasons. He wrote that those changes were probably due to vegetation.

We now know that Schiaparelli's canali were an illusion and that the seasonal changes in the planet's color are due to global dust storms. Space probes have revealed that the surface of Mars is rocky, barren, and cratered. The Viking landers of the 1970s did some simple experiments with Martian soil and found no signs of life. Still some people believed that life could be found there, if we only knew where to look.

No one imagined that the right place to look might be right here on Earth until 1996. In August of that year, a group of NASA scientists announced that a meteorite that they had been studying showed evidence of Martian fossils. They believe they have discovered chemical signs of ancient life that arose on Mars at about the same time as life began on Earth. They even found microscopic structures that resembled fossils of earthly bacteria in shape, but were much smaller.
Mars Fossil
(NASA image from Sky Publications Web site)

Interpreting their findings as Martian fossils is still controversial. Still, many scientists believe that if bacterial life originated on Mars billions of years ago, it may still be there today. In a few years, a spacecraft is expected to go to Mars and bring rock and soil samples of the planet back to Earth. Planetary scientists are now deciding where that craft should land. In choosing a landing site, one of their questions is where on Mars are we most likely to find evidence of past or present life. If that mission goes well, we may have an answer to the question of life on Mars once and for all.


Find Out More

That meteorite was designated ALH84001, because it was the most interesting sample collected in the Allan Hills region of Antarctica by the Antarctic Search for Meteorites (ANSMET) project during the summer of 1984-5. However, it was not recognized as a piece of Mars until 1993.

To find out more about meteorite ALH 84001 and other meteorites from Mars, go to NASA's Mars Meteorite Home Page or read Dr. Fred's book Martian Fossils on Earth? The Story of Meteorite ALH84001 (Millbrook Press, 1997).

To tour the Mars and the rest of the Solar System on-line-- including a great collection of images from the 1997 Mars Pathfinder Mission -- at NASA's Planetary Photojournal Web site.


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Text copyright 1998-2003 by Alfred B. Bortz, all rights reserved

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