Life on mars

People have always though that there may be life on  another planetThere have been many mission to other planets and The moonOn December  4 1996 the mars pathfinder landed on mars
Scientists have long speculated about the possibility of life on Mars owing to the planet's proximity and similarity to Earth. Although fictional Martians have been a recurring feature of popular entertainment, it remains an open question whether life currently exists on Mars, or has existed there in the past.The indication of life hinges on three important pieces of evidence, all discovered within mineralized fractures in the meteorite in close proximity to each other. One is the discovery of abundant polycyclic aromatic  

hydrocarbons (PAHs) on the fracture surfaces. These are a family of complex organic molecules which are commonly found on dust grains and certain types of meteorites in outer space, presumably formed by non-biological chemical reactions. However, when micro-organisms die they break down into PAHs as well. The mixture of PAHs found on ALH84001 is very different from that found on dust grains and other meteorites, suggesting the possibility of a biological origin. Thousands of different types of PAHs are found all over the Earth, but those in ALH84001 do not appear to be contaminants which have leaked into the meteorite.Another line of evidence involves unusual mineral phases
found beside the PAHs. These carbonate minerals form "globules" about 50 micrometers across, some of which
have cores containing manganese and rings of iron carbonate and iron sulfides, and also contain magnetite
and pyrrhotite. These minerals bear strong resemblance to mineral alterations caused by primitive bacteria onEarth. This diversity of minerals in such a small area,formed under the presumed conditions, seem to make a non-biological origin unlikely.

 

About mars-life on mars

Named after the Roman god of war, the planet Mars is located four planets from the Sun. Commonly referred to as “The Red Planet,” Mars tends to give off a reddish hue when viewed from Earth. This is believed to be caused by an abundance of iron oxide on the planet’s surface. Mars is about half the size of the Earth. Mars has two moons, Phobos and Deimos, both of which are relatively small in size and not shaped in perfect spheres like the Earth’s moon. Mars can be easily seen from Earth without a telescope at a brightness that is only surpassed by the planet Venus, the Moon and the Sun.

Mars has long been considered the most realistic location for life in our solar system, aside from Earth. Many even believe that intelligent life may have once existed on the planet. Scientific exploration of Mars has not produced any evidence of life on the planet. It is believed that the harsh surface environment and extreme solar radiation that saturates the surface of the planet is not capable of sustaining any kind of life. Before space exploration, Mars was considered the best candidate for harboring extraterrestrial life. Astronomers thought they saw straight lines crisscrossing its surface. This led to the popular belief that irrigation canals on the planet had been constructed by intelligent beings. In 1938, when Orson Welles broadcasted a radio drama based on the science fiction classic War of the Worlds by H.G. Wells, enough people believed in the tale of invading Martians to cause a near panic. The average recorded temperature on Mars is -63° C (-81° F) with a maximum temperature of 20° C (68° F) and a minimum of -140° C (-220° F).




Barometric pressure varies at each landing site on a semiannual basis. Carbon dioxide, the major constituent of the atmosphere, freezes out to form an immense polar cap, alternately at each pole. The carbon dioxide forms a great cover of snow and then evaporates again with the coming of spring in each hemisphere. When the southern cap was largest, the mean daily pressure observed by Viking Lander 1 was as low as 6.8 millibars; at other times of the year it was as high as 9.0 millibars. The pressures at the Viking Lander 2 site were 7.3 and 10.8 millibars. In comparison, the average pressure of the Earth is 1000 millibars.