=START= XMT: 18:48 Fri Oct 26 EXP: 19:00 Fri Nov 02 MARS EXPERTS GATHER TO DEBATE THE QUESTION, "ARE WE ALONE?" CAPE CANAVERAL, FL (OCT. 26) REUTER - Scientists from the United States, the Soviet Union and Europe will gather at the weekend to explore the possibilities, or dismiss the theories, of life on the ''angry red planet,'' Mars. Experts are divided into three camps -- those who think Mars never could have supported life, those who suspect some type of microscopic bacteria do live on the planet, and those who believe that life did exist on Mars but is now extinct. ''We expect some fireworks because of the widely differing opinions about the existence of life on Mars,'' said Dr Imre Friedmann, organiser of the conference at Florida State University. Friedmann has published research raising the possibility that primitive Martian life forms lived and died, similar to lichens found thriving in Antarctic rocks. Finding an answer to the question ''Are we alone?'' is essential before humans can set foot on Mars, scientists say, to protect both human explorers and the Martian environment from alien intrusions. President George Bush set a goal of 2019 for US astronauts to land on Mars. The Soviets want to get cosmonauts there nine years sooner. Both plan unmanned life-seeking preparatory missions in the next few years. Most knowledge about Mars has come from the US National Aeronautics and Space Administration's two Viking probes launched in 1975. From orbit, the spacecraft photographed polar ice caps and dry lake beds and stream channels. Automated life-seeking landers analysed the atmosphere and surface composition but turned up only inconclusive evidence of biochemical reactions in the soil. That knowledge is not enough for scientists who want to know why Earth and Mars evolved so differently in spite of their relatively close size and position in the solar system. Exobiologists, specialists in the hunt for life beyond Earth, say water -- the necessary element to sustain life -- is frozen at the poles and flowed across the red planet three to four billion years ago. They say Mars had a more Earth-like climate and active volcanoes then, too. But the planet's interior cooled quickly and its crust stopped moving. Unlike Earth, Mars is seismically dead and without heat to power plate tectonics, it cannot recycle life-sustaining elements. =END=