Local warming of the environment by volcanism and impacts would have been sporadic, but there should have been many events of water flowing at the surface of Mars. The exact causes are not well understood but may be related to a combination of processes including loss of early atmosphere, or impact erosion, or both. Part of the liquid water inventory sublimed and was transported to the poles, while the rest became trapped in permafrosta subsurface ice layer. If it did, it was probably microbialexisting communally in fluids or on sediments, either free-living or as biofilmsrespectively.
Data in table from Consolmagno and Schaefer: However, the proximity of these planets to the Sun made them vulnerable to the stripping effects of the Solar Wind.
Especially in the early history of the Sun, when it is believed to have undergone a violent "T-Tauri" phase associated with the ignition of its internal fusion generator, any atmospheric gases around the inner terrestrial planets would probably have been stripped away. Thus, all the inner planets lost their primitive atmospheres early in the history of the Solar System.
However, volcanism associated with the internal differentiation of the terrestrial planets offered another means of producing at atmosphere. All volcanic eruptions release gases from a planet's interior - in fact, the gas is the "fizz" that drives lava to the surface, much in the same manner as a shaken up bottle of soda.
Gases released by volcanic eruptions collect slowly near the planet's surface and eventually build up to become a Secondary Atmosphere. These atmospheres tend to be rich in CO2 and H2O, with significant abundances of a range of minor gases: Many of these minor gases will react with one another and with materials on the planet's surface, especially in the presence of water, and the end result is a secondary, volcanogenic atmosphere that is dominated by CO2 and contains significant proportions of N2.
Of these gases, two - CO2 and H2O - are Greenhouse Gases, which means they help to retain heat energy in the atmosphere. The presence of these gases allows the atmosphere to hang onto more of the heat energy reaching the planet from the Sun, and thus permits the surface to warm.
So a CO2-rich atmosphere will lead to a warm er planet - how warm depends o n that planet's proximity to the Sun, and the mass of CO2 in the atmosphere. Table in Hartmann outlines current estimates of the respective volatile inventories of Mars, Earth and Venus. Note that abundances of CO2 and N2 on Earth and Venus are believed to be very similar - as these planets are the same size, they are believed to have begun with similar inventories of gases trapped in their interiors.
While all of these numbers are highly uncertain especially estimates of fixed gas components in planetary crusts! Examining Table 1, we see that both Venus and Mars preserve "volcanogenic" proportions of atmospheric gases, if not actual abundances - atmospheric pressures on Mars are times lower than on Venus.
The Earth, however, has a very different atmospheric makeup - dominantly nitrogen-oxygen, with a little water vapor and argon, and only ppm or 0.
Ifas is believed, the Earth's atmosphere started out with similar gas proportions as those of Mars and Venus, then we need to answer some questions: A specific pressure range? Something in terms of composition? What basic things do these processes need to "go"? The Atmosphere of Venus: Under such conditions, H2O probably could not have persisted as a free liquid, which means that water-mediated processes such as carbonate formation and biological carbon uptake may not have been able to operate.
Thus, CO2 exhaled from volcanoes would progressively build up in the atmosphere, which means the planet would get progressively hotter. The Venusian atmosphere, then, is a water-free "runaway greenhouse," which developed largely because liquid water never persisted on the Venusian surface.
The Atmosphere of Mars: The current Martian atmosphere might be called a Residual Atmosphere, because much of its original inventory of gases has been removed either by planetary processes, or by progressive loss to interplanetary space.
The average atmospheric pressure at the Martian surface hovers around 6 mbars, which is curious, as that is the lowest pressure at which liquid water can exist.
Today such H2O as there is on Mars must be bound up as ice in thick permafrost regions below the planet's surface, and at the polar caps. Nonetheless, the Martian surface is rich in landforms that indicate the presence of abundant liquid water in the past. So on Mars, it is reasonable to hypothesize about possible climate conditions that might allow for the generation of these landforms.
Plot of surface temperature versus surface pressure on Mars as a function of incident solar energy. Dotted horizontal line marks the freezing point of water, and the three solid curves represent three possible options on the strength of incident solar energy.Life on Mars or Not - The Heavens.
Once an object of superstition, awe and fear. Now a vast region for growing knowledge. The distance of Venus, the atmosphere of Mars, the size of .
Continue reading "Meteorite May Contain Proof of Life on Mars, Researchers Say" the meteorite is Martian in origin. rekindle the debate as to the possible existence of biological activity. Bilbliography and online stories of the science fiction author Stephen Baxter.
The question of Martian life is an age-old one. There are many theories on the history of Mars, and its inhabitants, or lack thereof. The history and origin of Mars is widely debated, mostly between evolutionists and creationists, though the debate is mainly focused on the origin of the Uni. "The consideration of possible biotic scenarios for the origin of the ovoid structure in into the evolution of life on Mars.
Searching for life. early in the history of life. Some. A recent analysis of Martian meteorite EETA found ppm ClO 4 −, ppm ClO 3 −, and 16 ppm NO 3 −, most likely of Martian origin. The ClO 3 − suggests presence of other highly oxidizing oxychlorines such as ClO 2 − or ClO, produced both by UV oxidation of Cl and X-ray radiolysis of ClO 4 −.