Water and Life on Mars

Of all the planets one has inspired emotions and inflamed the imagination like no other. The ancient Egyptians called it the Red One, the Babylonians the Star of Death, to the Greeks it was the Fiery One, the Romans called it Mars.

Humans have speculated about the possibility of life on mars for a long time. One of NASA's stated missions is to find out whether or not life exists or has existed on Mars. A Viking Lander in the 1970’s directly sampled the soil of Mars for microbial life, but found none. So NASA decided to take a different approach and took as a theme “Follow the Water.” If life as we know it does or has existed on Mars then there had to be water. This is not a new idea. Water has played an important role in the search for life on Mars for over a hundred years.

In the fall of 1877 an Italian astronomer, Giovanni Schiaparelli, saw through his small telescope fine lines that appeared and disappeared as he strained to see detail on the Martian surface through our atmosphere’s dancing air. He called the fine lines he thought he saw canali, channels or canals in Italian. An English translator chose canal as the meaning of canali implying a construction by intelligent beings.

In 1894 a Boston businessman, Percival Lowell, built an observatory outside Flagstaff Arizona dedicated to the study of his all consuming passion, the planet Mars. Lowell believed that the canals Schiaparelli saw were built by intelligent creatures to bring precious water from the planet’s ice caps to irrigate the desserts of their arid and dying planet. He spent his life trying to prove it.

The writer H.G. Wells further fired the public’s imagination about intelligent life on Mars with his story, War of the Worlds, where Martians in giant machines come to conquer the Earth.

To answer the question of water on Mars NASA took several approaches. They looked for the geological signs such as those found on Earth associated with water. After all they reasoned, the effects of oceans or rivers would most likely leave the same marks on the rocks and soil of Mars as they did on Earth. Probes were launched to photograph and remotely study in detail the surface.

The Mars Reconnaissance Orbiter (MRO) launched in 2005 employed high resolution photography to photograph the surface for physical features similar to those found on Earth caused by liquid running water such as gullies and river beds. (See Photo - Mars) Ground penetrating radar equipment aboard the MRO probed up to a half mile deep searching for signs of ice and finding it near one of the Martian poles. Another instrument package aboard the Orbiter detected chemical signs of water in the form of carbonates. The scientists at NASA believe the carbonates were formed by the action of water on rocks in the Martian soil. Strong evidence of water ice had been found but more proof was needed.

Finally in 2008 the Phoenix Lander found the proof NASA needed It scraped a small trench in the red soil of Mars and found water ice. The case for life on Mars was now strong.

Following the discovery of water ice on Mars NASA plans to launch the Mars Science Laboratory (MSL) in 2011. MSL is a roving chemical laboratory that can drive around Mars similar to the two current rovers, Spirit and Opportunity, but much more sophisticated. One of its objectives is to determine if conditions on Mars now or in the past has or has ever supported life.

Percival Lowell would be pleased.