Astronomy

Astronomers in the past suspected the presence of intelligent life form in Mars , fueled in part by the announcement in 1877 by Giovanni Virginio Schiaparelli , an Italian astronomer at the Milan Observatory in Italy of what he called canali ' on the planet 's surface later findings which showed no such canals were to be found on the Martian surface ended speculations as to whether any life forms could possibly survive in its harsh environment (Keyes . Viking missions in the 1970s flashed back pictures of the dry , barren Martian surface , disappointing those who

had hoped of finding at least traces of microscopic life . But 20 years later , a stunning development occurred : the National Aeronautics and Space Society (NASA ) announced the discovery of a meteorite discovered in an Antarctic ice field in 1984 , that suggested evidence of fossil life on Mars . Hailed as glorious ' by the late astronomer Carl Sagan , the NASA finding has drawn scientists into a controversy and reignited interest in the red planet (Kellan . This focuses on the findings as regards the possibility that primitive life once existed on Mars and the current developments in the exploration of the red planet

On September 12 , 1996 , David McKay of NASA , testifying before the Subcommittee on Space and Aeronautics Committee on Science of the U .S Congress discussed the discovery of evidence supporting the theory that life once existed on Mars . NASA 's evidence was the meteorite , named ALH84001 (ALH stands for Alien Hills ) aforementioned . Estimated to have been formed in the Martian crust 4 .5 billion years ago , ALH84001 belonged to a family of meteorites , designated as SNC meteorites , whose oxygen isotopes , like a person 's fingerprint , distinguished them from other rocks emanating from outer space . Laboratory analysis of pockets of gas trapped in one of these meteorites showed similarity with the gas found in the Mars atmosphere by the Viking Lander missions in 1976 . It was theorized that these meteorites , numbering a dozen , were remnants of particles ejected into the atmosphere when an asteroid collided with Mars some 16 million years ago

Normally , the impact of a planet 's collision with an asteroid produces a crater as giant rocks are hurled upward , most of these falling back to the surface . Mars ' surface is strewn with such enormous debris . At times , some rock fragments are thrown violently into space , escaping the planet 's gravity . Scientists figure a similar catastrophe in Mars ejected ALH84001 into space , propelling it around the sun in an elliptical orbit before it was drawn by the gravity of earth . Like half of the SNC meteorites that have been recovered , ALH84001 landed in Antarctica . The meteorite has been dated , using carbon-14 methods , to have been on earth from 12 ,000 to 13 ,000 years . Using electron microscopes and state-of-the-art technology , scientists found traces of minerals in the meteorite although these suggested nothing very unusual What intrigued the analysts was

the presence of unusual , every small objects or forms , which could be interpreted as the remains of...