Mars or Red Planet was named after the god of war of the ancient Romans. Mars is the only planet whose surface can be observed in detail from the Earth. It is the fourth closest planet to the Sun and is the second nearest planet to the Earth and will perhaps be the first planet visited by humans.
Before the space exploration, Mars was believed to be the best candidate for harboring extraterrestrial life. When ancient astronomers saw straight lines crossing planet’s surface, they considered that to be the irrigation canals, which had been constructed by intelligent beings. Another important reason for scientists to expect life on Mars had to do with the evident seasonal color changes on the planet’s surface. This occurrence led to assumption that conditions might maintain a bloom of Martian vegetation in the warmer months and cause plant life to turn out to be dormant in colder periods.
However in July 1965, Mariner 4, broadcasted 22 close-up pictures of Mars. It was then revealed that the surface of Mars contains many craters and naturally occurring channels however no evidence of artificial canals or flowing water was found. When in July and September 1976, Viking Landers 1 and 2 touched down on the surface of Mars, it was discovered that there is unexpected and enigmatic chemical activity in the Martian soil, however provided no clear proof for the existence of living microorganisms in the soil around landing sites. However, there is still a chance that life existed on Mars at some time in the distant past. #1
Atmosphere on Mars
The atmosphere of Mars is quite different from that of Earth. It mostly constitutes of carbon dioxide with little amounts of other gases. Mars has a very thin atmosphere, which consists of six common components:
- Carbon Dioxide (CO2): 95.32%
- Nitrogen (N2): 2.7%
- Argon (Ar): 1.6%
- Oxygen (O2): 0.13%
- Water (H2O): 0.03%
- Neon (Ne): 0.00025 %
Compared to the air on Earth, Mars’ atmosphere contains only about 1/1,000 of water in the air. However even this little amount can condense out, making clouds that ride high in the atmosphere or spin around the slopes of towering volcanoes. Local patches of early morning fog can develop in valleys. At the Viking Lander 2 site, a thin layer of frost covered the ground each winter. There is data that in the past a denser Martian atmosphere may have allowed water to flow on the planet. Evidence advocates that Mars once had rivers and even an ocean. Since Mars’ atmosphere gradually depleted into outer space, the surface water started to permanently evaporate. At present the only water present on Mars in either frozen in the polar caps or can be found underground.
Temperature and Pressure
The average temperature on Mars is -63° C (-81° F) with a maximum observed temperature of 20° C (68° F) and a minimum observed temperature of -140° C (-220° F). Mars’ thin atmosphere generates a greenhouse effect, but it is much smaller than what we see on Venus and Earth. Green house effect on Mars is only sufficient to raise the surface temperature by 5 degrees Celsius.
Mars’ surface has an average pressure of about 7 millibars, however it changes significantly with altitude from approximately 9 millibars in the deepest basins to about 1 millibar at the top of Olympus Mons. However it is strong enough to hold very strong winds and vast dust storms.
Mars Core
From the data collected near the surface and statistics collected on the planet, it is believed that Mars has a dense core of about 1700 km in radius; a molten rocky mantle to some extent denser than Earth’s one, and a thin crust. Information from Mars Global Surveyor signifies that Mars’ crust is approximately 80 km thick in the southern hemisphere; however it is only about 35 km thick in the northern hemisphere. Mars’ comparatively low density compared to the other terrestrial planets shows that its core most likely contains a comparatively large portion of sulfur in addition to iron (iron and iron sulfide).
Topography of Mars
The southern hemisphere of Mars has mainly ancient cratered highlands, which are to some extent similar to the Moon. On the contrary, most of the northern hemisphere has the plains which are much younger, lower in elevation and have a much more complex history. Mars Global Surveyor has formed a nice 3D map of Mars which clearly shows these features. Mars has higher mountains, and deeper canyons in comparison to any other planet of Solar System. #2
Mars Moons
Mars has two moons called Phobos and Deimos. One important fact about the moons is that one of Mars’ moons is going to crash into it. Phobos orbits the planet at very low altitude that it’s going to finally be torn apart by the gravity of Mars. It will continue to exist as a ring for a few years, and then its remains will rain down on Mars.
Mars Anomalies
One Mars anomaly that gained huge popularity was the “Face on Mars” in the 1970s. During the mission of Viking 1, a spacecraft launched to survey the surface of Mars, it captured images of what appeared to be a giant geological feature shaped into a face. The face looked a lot like that of a human. Images of the same place though exposed the Face on Mars as nothing more than a mesa that basically looked like a face due to poor image resolution. There are some other images of Mars which also gave an idea about a lot of strange occurrences. Some of these images contained structures that looked like trees, glass tunnels, domes, animal fossils and hieroglyphs. Some also contained shapes that strongly resembled the crop circles and there is one that looks like an Egyptian queen.
Face on Mars
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[Images] www.nasa.gov
[Video] www.nasa.gov
