Scientists have long speculated about the possibility of life on Mars owing to the planet's proximity and similarity to Earth. Fictional Martians have been a recurring feature of popular entertainment of the 20th and 21st centuries, but it remains an open question whether life currently exists on Mars, or has existed there in the past.
The Mariner 4 probe performed the first successful flyby of the planet Mars, returning the first pictures of the Martian surface in 1965. The photographs showed an arid Mars without rivers, oceans or any signs of life. Further, it revealed that the surface (at least the parts that it photographed) was covered in craters, indicating a lack of plate tectonics and weathering of any kind for quite some time. The probe also found that Mars has no global magnetic field that would protect the planet from potentially life-threatening cosmic rays. The probe was able to calculate the atmospheric pressure on the planet to be about 0.6 kPa (compared to Earth's 101.3 kPa), meaning that liquid water could not exist on the planet's surface. But when Mars was young the atmospheric pressure was much higher maybe half of that of Earth since it would have still had it's atmosphere, and water probably existed on the planet's surface.. After Mariner 4, the search for life on Mars changed to a search for bacteria-like living organisms rather than for multicellular organisms, as the environment was clearly too harsh for these.
How early Mars might have looked
This story will explain why this planet’s environment is as we see it today. Although this story could have really happened- if not in this way then in some similar manner. However, there is life on Mars now and in the past. It requires a human mission to go the planet not a roving computerized satellite controlled machine to find it: since scientists can argue over a machine’s discoveries and make the finds inconclusive or explain the discovery away.
This is where life on Mars might exist Today
Science has led us to believe that liquid water is necessary life as we know it. That it cannot exist on the surface of Mars under its present low atmospheric pressure, and temperature, except at the lowest shaded elevations for short periods, and liquid water does not appear at the surface itself. However, in June 2000, evidence for water currently under the surface of Mars was discovered in the form of flood-like gullies. Deep subsurface water deposits near the planet's liquid core might form a present-day habitat for life. However, in March 2006, astronomers announced the discovery of similar gullies on the Moon, which is believed never to have had liquid water on its surface. The surface water on the moon was later confirmed by the LRO/LACROOS mission. There is just one major problem with this discovery- Mars is not the moon ! They are two completely different planets.
Ice discovered beneath the soil by Phoenix Mission
In March 2004, NASA announced that its rover Opportunity had discovered evidence that Mars was, in the ancient past, a wet planet. This raised hopes that evidence of past life might be found on the planet today. ESA confirmed that the Mars Express orbiter had directly detected huge reserves of water ice at Mars' South Pole in January 2004. On July 28, 2005, ESA announced that they had recorded photographic evidence of surface water ice near Mars' North Pole. The Phoenix Mars Lander from NASA, which landed in the Mars Arctic plain in May 2008, confirmed the presence of frozen water near the surface. This was confirmed when bright white crystalline material, exposed by the digging arm of the Lander, was found to have vaporized and disappeared in 3 to 4 days after exposure. This has been attributed to sub-surface ice, exposed by the digging and sublimated on exposure to the atmosphere. So there is still water on the planet it is in the form of ice under the surface. This could indicate that liquid water could exist deep underground where conditions would be more favorable.
The North Pole of Mars in the early Amazonian Period
Recent analysis of Martian sandstones, using data obtained from orbital spectrometry, suggests that the waters that previously existed on the surface of Mars would have had too high a salinity to support most Earth-like life.. This analysis found that the Martian water in the locations they studied all had water salinity, aw = 0.78 to 0.86—a level fatal to most Terrestrial life. Haloarchaea, however, are able to live in hypersaline solutions, up to the saturation point. It means that Humans could not existed using such water but who is to say if the Ancient Astronauts could not have used it or any kind of life that lived naturally on the planet, and since the Ancient Astronauts were not native to the planet they could have constructed desalination plants to purify the water had it been toxic to them.
The Face on Mars (inset Viking Mission. Large face HR by later mission)
The Face on Mars is one of the most striking and remarkable images taken during the Viking missions to the red planet. Unmistakably resembling a human face, the image caused many to hypothesize that it was the work of an extraterrestrial civilization. When it was first imaged, and into the 21st century, the "Face" was near universally accepted to be an optical illusion, an example of pareidolia- a natural geological feature resembling a human face. After an analysis of the higher resolution Mars Global Surveyor data NASA stated, "A detailed analysis of multiple images of this feature reveals a natural looking Martian hill whose illusory face-like appearance depends on the viewing angle and angle of illumination".
The Sphinx and Pyramids on Earth. Is there any precedence for it from Mars?
The Cydonia facial pareidolia inspired individuals and organizations interested in extraterrestrial intelligence about visitations to Earth from the Red Planet. The images were published in this context in 1977. Some commentators, most notably Richard C. Hoagland, believe the "Face" to be evidence of a long-lost Martian civilization along with other features they believe are present, such as the pyramids of Cydonia on Mars, which they argue are part of a ruined city. However, the ruined city may have actually have been a ruined city. The face may not be a face even though both are in the same area. There are also many other features on Mars that indicate the possibility of habitation there by someone.
