Is there water and life on mars?

Unlike Earth, since there are no oceans to obscure the planet Mars, its topography is now meliorate explored and known than that of Earth (Australian Geographic 2003). It has the largest known volcano in the Solar System, Olympus Mons, three times as high as Mt Everest, arid the long-run and deepest known canyon, V totallyes Marineris, 4000 km long and 10 km deep (Australian Geographic 2003).Mars has no continental plate movement, so its surface isnt constantly reworked by mountain-building processes. As a result, much of the landscape is as it was one million millions of years past (Australian Geographic 2003).NASA researchers are taking lessons from the debate about life on Earth to Mars. Their future day missions will incorporate cutting-edge biotechnology designed to detect individual molecules made by Martian organisms, either living or long shortly (Zimmer 2005).The search for life on Mars has become to a greater extent urgent thanks in part to probes by the two rovers no w roaming Mars surface and youthful(prenominal) spaceship that is orbiting the planet. In recent months, theyve made a series of astonishing discoveries that, formerly again, tempt scientists to believe that Mars harbors life or did so in the past. At a February conference in the Netherlands, an audience of Mars experts was surveyed about Martian life. Some 75 percent of the scientists said they thought life once existed there, and of them, 25 percent think that Mars harbors life today (Zimmer 2005).The search for the fossil remains of primitive single-celled organisms like bacteria took off in 1953, when Stanley Tyler, an economic geologist at the University of Wisconsin, puzzled over some 2.1 billion-year-old rocks hed gathered in Ontario, Canada (Zimmer 2005). His glassy black rocks known as cherts were loaded with strange, microscopic filaments and hollow balls. working(a) with Harvard paleobotonist Elso Barghoorn, Tyler proposed that the shapes were actually fossils, left behind by ancient life-forms such as algae. Before Tyler and Barghoorns work, a couple of(prenominal) fossils had been set that predated the Cambrian Period, which began about 540 million years ago (Zimmer 2005). Now the two scientists were positing that life was present much earlier in the 4.55 billion-year history of the planet. How much further back it went remained for later scientists to discover (Zimmer 2005)?In the beside decades, paleontologists in Africa found 3 billion-year-old fossil traces of microscopic bacteria that had lived in massive marine reefs (Zimmer 2005). Bacteria can also form what are called biofilms, colonies that take in thin layers over surfaces such as rocks and the ocean floor, and scientists keep up found solid evidence for biofilms dating back 3.2 billion years (Zimmer 2005).Fluvial Landforms geological features putatively organise by wet were identified in images of Mars taken by the Mariner and Viking spacecraft in the 1970s (Bell 2006). The se landforms included enormous take carved by catastrophic floods and large-scale valley networks somewhat reminiscent of river drain systems on Earth. Over the past decade, images from the Mars world(prenominal) Surveyor, which has been orbiting Mars since 1997, stomach revealed spectacular examples of extremely small and seemingly young gullies formed in the walls of some craters and canyons. These observations indicate the past presence of liquid water on the Martian surface or just below it however not necessarily for long periods (Bell 2006). The water from the catastrophic floods, for example, may have lasted only a few days or weeks on the surface before freezing, seeping back into the ground or evaporating.Furthermore, the networks of river-like valleys shown in the Viking orbiter images do not have the resembling characteristics as terrestrial river valleys when seen at higher resolution (Bell 2006). The Martian valleys could have formed entirely from subsurface wate r flow and ground erosion a process known as sapping-rather than from water moving over the surface. The gullies observed in the Mars Global Surveyors images may also be the result of water seeping underground below ice or from buried snow deposits (Bell 2006). Although these features are stunning and dramatic indicators of water on Mars, they do not severely prove that the Red Planet once had a warmer, wetter, more Earth-like environment with long-lasting lakes and rivers.In the past few years, however, new satellite images have provided much more convincing evidence that st fitted, Earthlike conditions prevailed on Mars for long periods (Bell 2006). One of the most exciting discoveries is a class of features that look like river deltas. The best and largest example, photographed by the Mars Global Surveyor, is at the end of a valley network that drains into Eberswalde Crater in a region southeast of the Valles Marineris canyon system (Bell 2006). This drainage system terminates in a 10-kilometer-wide, layered, fan-shaped landform characterized by meandering ridges that crosscut one another(prenominal) and show varying degrees of erosion. To umpteen geologists, this feature has all the characteristics of a delta that formed at the end of a sediment-bearing river flowing into a shallow lake.Further evidence of an Earth-like climate in Marss past comes from high-resolution images, taken by the Mars Odyssey and Global Surveyor orbiters, of the small-scale valley networks on the plateaus and walls of the Valles Marineris canyon system. Unlike previously identified valley networks that seem to have formed largely from subsurface flow, these newly found networks have characteristics that are consistent with their formation by rainfall or snowmelt and surface runoff. For example, the networks are arranged in dense, branching patterns, and the lengths and widths of the valleys increase from their sources to their mouths. Moreover, the sources are turn up along th e ridge crests, suggesting that the landscape was molded by precipitation and runoff. Indeed, these landforms provide the best evidence to date that it may have rained on Mars.A more explorative possibility is that these runoff features arose relatively recently, perhaps one billion to 1.5 billion years after Mars formed. To estimate the ages of Martian landforms, researchers count the number of have-to doe with craters on the feature the more refers the region has endured, the older it is. This dating method, however, has many uncertainties it can be difficult to distinguish between primary and secondary impact craters and volcanic calderas, and erosion has destroyed the evidence of craters in some regions (Bell 2006). Still, if these surface runoff valleys do turn out to be relatively young, Mars may have had an Earth-like climate for as much as a third of the planets history and perhaps longer if even younger valleys are in the end identified.Yet another piece of evidence supp orting persistent liquid water on Mars is the observation of truly enormous amounts of erosion and sedimentation in many parts of the planet. Making calculations based on new orbital imaging data, researchers have determined that the rate at which sediments were deposited and eroded in the first billion years of the planets history may have been about a million times as high as the present-day rate (Bell 2006).But what process could have transported the massive amount of sediment needed to bury almost everything in the Gale Crater region? (Bell 2006) Scientists believe flowing water offers the best explanation. Studies of erosion and sedimentation rates on Earth suggest that wind could have moved some of the Martian sediment in the past (just as it is doing today, albeit at a very slow pace). No viable wind-based scenario, however, can explain the rapid transport of millions of cubic kilometers of material across large fractions of the planets surface, which apparently occurred rep eatedly during Marss other(a) history. Flowing water, though, has routinely moved gargantuan amounts of sediment on Earth and could have done so on the Red Planet as well.In accessory scrutinizing the shape of Martian landforms, scientists have searched for hints of liquid water in the composition of the planets minerals (Bell 2006). One of the reasons why researchers had long believed that Mars never enjoyed an extensive period of warm and wet climate is that much of the surface not covered by wind-borne dust appears to be composed of material that is largely unweathered pristine volcanic minerals such as olivine and pyroxene. If water had flowed over the surface for a long time, the argument went, it would have chemically altered and weathered the volcanic minerals, creating dusts or other oxidized, hydrated phases (minerals that incorporate water molecules or hydroxide ions in their crystal structure).The emerging paradigm is that Mars had an extensive watery past puddles or p onds or lakes or seas (or all of them) existing for long periods and exposed to what must have been a thicker, warmer atmosphere. During the first billion or so years of Martian history, the Red Planet was a much more Earth-like place, probably hospitable to the formation and evolution of life as currently known. The Martian environment began to change, however, as sulfur built up, the waters became acidic and the planets geologic activity waned (Bell 2006). Clays gave way to sulfates as the acid rain (of sorts) continued to alter the volcanic rocks and break dispirited any carbonates that may have formed earlier. Over time, the atmosphere thinned out perhaps it was lost to space when the planets magnetic field shut off, or maybe it was blown off by catastrophic impacts or sequestered somehow in the crust. Mars eventually became the cold, arid planet recognized today.This new view of Mars is not nevertheless universally accepted, however. Key questions remain unanswered (Bell 2006 ) How long did the waters flow in the Eberswalde delta for decades or millennia? Where are all the sediments that appear to have been eroded from Meridiani Planum and places such as Gale Crater? And were they eroded by water or wind or something else? What is the global abundance of clay minerals on Mars, and were they ever major components of the planets crust? And, most vexing, where are the carbonates that should have formed in the warm, wet, carbon dioxide-rich environment but have not yet been observed anywhere on Mars, not even in the older terrains where clays have been detected? Acidic water could have destroyed the bulk of the carbonates but surely not all of themPerhaps the most important question of all is Did water or life ever exist on Mars, and if so, was it able to evolve as the environment changed so dramatically to the present-day climate? (Bell 2006) The answer depends in large part on how long the Earth-like conditions lasted. What can be deduced is that the past decade of discoveries on Mars may be only a small taste of an even more exciting century of robotic and eventually human exploration.ReferencesAustralian Geographic, (2003) Life on Mars. 08161658, Jul-Sep2003, Issue 71Bell, J., (2006) The Red Planets Watery Past. Scientific American, 00368733, Dec2006, Vol. 295, Issue 6Zimmer, C., (2005) Life on Mars? Smithsonian, 00377333, May2005, Vol. 36, Issue 2