Wednesday, April 8, 2009

Did warming helped water to vanish from Mars?

Will our Earth will look same as Mars in future?
Dr. Nitish Priyadarshi

When I began studying Environmental Geology, I was told that the depletion of water, global warming crisis are going to be the most important issues the planet Earth would have to face in coming decades or centuries.
The political pundits were not impressed. After years of neglect, global warming and water depletion have suddenly become matters of wide spread international concern. Water is depleting, desert is expanding and lots more.

You must be now thinking that why I am writing on such issues which is related to Earth and not to Mars. Answer is below.

According to latest concept it is now clear that Mars once definitely supported a watery environment. It is clear from the pictures that Mars is covered with features that are best explained by the movement of water, either in catastrophic floods or the slow movement of groundwater.

If the water really existed on the Mars, which is now proved by different pictures, then where all the waters vanished? Was it the effect of warming or climate change which helped the water to escape from atmosphere? Our Earth is also passing through the same phase. If all the water from our atmosphere escapes, will our Earth will look same as Mars, devoid of water and life.

My concern is hidden in the present environmental condition of the Mars which is now devoid of water and life. Is our Earth is going to become desert like that of Mars in coming centuries.
Many of you must be thinking that my theory is merely hypothetical and nothing like this is going to happen to Earth. Future of Earth can never be Mars

It may be speculations but we must have to think seriously to save our planet for our coming generations. Really what happened to the water on Mars no body knows.
Evidences of ancient water on Mars:

Photo credits: NASA

It’s dustier than the road to death, colder than the devil’s kiss. Like much of Mars, the butter scotch plain is inhospitable, empty, ancient and dull.

Mars has always exerted a powerful attraction for people on Earth. Every two years it disappears, to stage a spectacular reappearance some time later as a fiery red object in the sky. Its blood-red color has inspired terror and war. In Hindu mythology this planet governs the health and carrier of humans.

It was only after the theoretical work Copernicus at the end of 15th century, and the observations Galileo at the beginning of the 17th, that Mars became just another world.
The quest for water on Mars has motivated many geologists and astronomers. The space probes have shown definitively that the amount of water vapor in the Martian atmosphere is only 0.003%. If it were to be condensed, it would form a layer on the surface with a thickness of just one-tenth of a millimeter.
The atmospheric composition is 95% carbon dioxide, 3% nitrogen, and only 0.1% oxygen: utterly unsuitable for any animal life.

Despite their disappointment, astronomers have not been discouraged. There was considerable surprise when the Viking Orbiters that had accompanied the Landers to Mars revealed other Martian landscapes. These Orbiters took 51,000 photographs of the surface, some of which had a resolution of as little as 10m. The photographs, distributed in the form of magnetic tapes to the principal research institutes around the world, have enabled us to study the whole of the Martian globe. Its general appearance is that of a inanimate, cold, desert world. But there are some notable features, including volcanoes, one of which, Olympus Mons, with a base 700 km across and a height of 27000 m, is the largest in the whole solar system. There are enormous impact basins, such as Argyre, which is 600 km in diameter and 1000 m deep.

Above all, however, the great surprise was the dried-up river-beds, some as much as 15 km wide, and whose discharge must have been 1000 times that of the Amazon, our greatest river! If liquid water existed on Mars in such quantity, would there not have been a denser atmosphere, which would imply a far more temperate climate, perhaps favorable to the spontaneous appearance of life?

In previous centuries, astronomers thought that the dark areas they saw on Mars through their telescopes might be seas, and, at the end of the 19th century there was much speculation, led by Percical Lowell, about the possibility of Martian canals. By the the early decades of this century, however, it had become clear, because of the very low atmospheric pressure, that little or no surface water could exist on the Red Planet today. In 1969, Mariner 9 provided the first strong evidence that liquid water had flowed on the surface of Mars in the remote past. Among the thousands of images it sent back from orbit were those of flat-floored channels with eroded banks, sand bars and teardrop-shaped islands, channels with second- and third-order tributary systems, and braided channels which, had they been encountered on Earth, would unhesitatingly have been attributed to episodic flooding. Later probes have added to the evidence of water-carved channels and other features on Mars. The fact that Mars had flowing water implies that conditions on the planet were once very different than they are today. Yet, curiously, there are no signs that it ever rained on the fourth planet. The water-carved systems on Mars are short and stubby, dividing little upstream, and ending abruptly as if the water had suddenly appeared at that spot rather than having fallen over a large area and become collected. The assumption is that the Martian water erupted from beneath the surface, welling up as a result of volcanic eruptions or asteroid impacts, and then flooded to form channels, and lakes, and perhaps even seas. Seeing the large amounts of fossilized evidences of the ancient water flow, it can also be assumed that water flowed in this red planet in the remote past and gradually vanished from the planet either due to global warming, which our Earth is facing today, or due to some other factors like geological or climate change.

How much liquid water existed on Mars in the past, and when? Does liquid water exist on Mars today? These are questions that fascinate scientists, especially astrobiologists, because they have a direct bearing on whether there was once life on Mars and, if so, whether it has survived to the present day. For this we have to search for fossils. The biological exploration of Mars is based on the idea that life appeared on that planet four billion years ago. Subsequently, it either disappeared 3.8 billion years ago (which is why we need to search for fossils), or else adapted to current conditions.

A large lake in the southern highlands of Mars is thought to have overflowed about 3.5 billion years ago, gouging out canyon as the torrent headed north and then spilled into the crater, forming a new lake. More evidences of catastrophic floods indicate ancient water flow on the surface of the red planet.

Images taken by Mars Global Surveyor (MGS) have provided some of the best evidence yet that water still occasionally flows on the Martian surface. Two gullies on the inside of craters, which were originally photographed by MGS in 1999 and 2001, and imaged again in 2004 and 2005, showed changes consistent with water flowing down the crater walls,

Other scientists, however, have challenged this explanation, pointing out that the gullies, and many others like them discovered by MGS, could have been caused not by water but by liquid carbon dioxide. The atmosphere of Mars is so thin and the temperature so cold that liquid water couldn't persist at the surface but would rapidly evaporate or freeze. Liquid carbon dioxide, on the other hand, has a lower freezing point (-56.6°C) and could stay liquid on the surface longer.

Striking new images of the Red Planet have raised hopes life could be found on Mars after all.

Scientists say they have photographic evidence that suggests liquid water may have been on the planet as little as five years ago.

In some of the pictures released by NASA, structures resembling to deltas formed on our Earth adds more evidence of water flow in past.

Whatever may be the truth, but it is now sure that there are ample of evidences that water did existed on this planet. According to the recent theories there are some fresh evidences of water flow. To me these are the ancient waters which were trapped in the remote past beneath the surface and which flow out from time to time carving latest flow structures on the upper surface of the red planet.

Where all the water went is an important question to scientists piecing together the planet’s geologic history. Perhaps some water seeped into the ground and froze, wound up in polar ice, or was lost from the atmosphere, but scientists can’t account for all of it.
Today, based on our observations from orbit, Mars appears to be very dry. There is little water in the atmosphere and only a small amount of water ice in evidence on the surface. Yet the planet is covered with features that are best explained by the movement of water, either in catastrophic floods or the slow movement of groundwater. Whether that water was present early in the history of Mars and was lost to space over eons, or is still present in great underground deposits of ice and groundwater, is a question whose answer must be left for the future exploration of Mars.

National Geographic Magazine, Jan. 2004. Mars, Is there life in the ancient ice?
Post a Comment