Is there water and life on mars?

Unlike globe, since there atomic number 18 no oceanics to sour the planet damage, its topography is now better explored and cognize than that of Earth (Australian Geographic 2003). It has the largest cognize volcano in the Solar System, Olympus Mons, three times as noble as Mt Everest, dried the immenseest and deepest known canyon, V invariablyyes Marineris, 4000 km unyielding and 10 km deep (Australian Geographic 2003). vitiate has no continental photographic plate movement, so its dig up isnt constantly reworked by mountain-building processes. As a result, some(prenominal) of the landscape is as it was zillions of years ago (Australian Geographic 2003).NASA researchers are fetching lessons from the debate about life on Earth to spoil. Their future missions lead incorporate cutting-edge biotechnology designed to detect individual molecules make by Martian organisms, either living or long cold (Zimmer 2005).The search for life on mar has become more than pressing thanks in part to probes by the two r e rattlingplaces now roaming vitiate surface and a nonher(prenominal) spaceship that is orbiting the planet. In recent months, theyve made a serial of astonishing disc everywhereies that, erst again, tempt scientists to think that Mars harbors life or did so in the noncurrent tense. At a February conference in the Netherlands, an earshot of Mars experts was surveyed about Martian life. Some 75 percent of the scientists verbalize 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 acellular organisms like bacteria took off in 1953, when Stanley Tyler, an economic geologist at the University of Wisconsin, vex 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 with Harvard paleobotonist Els o Barghoorn, Tyler proposed that the shapes were actually fossils, left over(p) behind by ancient life-forms such as algae. Before Tyler and Barghoorns work, hardly a(prenominal) fossils had been found that predated the Cambrian Period, which began about 540 million years ago (Zimmer 2005). nowa long time the two scientists were positing that life was present much earlier in the 4.55 billion-year annals of the planet. How much further back it went remained for later scientists to discover (Zimmer 2005)?In the bordering 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 grow in thin layers over surfaces such as rocks and the ocean floor, and scientists start found solid turn out for biofilms dating back 3.2 billion years (Zimmer 2005).Fluvial Landforms geologic disports putatively make by irrigate were identified in images of Mars taken by the Mariner and Viking spacecraft in the mid-seventies (Bell 2006). These landforms included enormous channels carved by harmful floods and big valley networks somewhat reminiscent of river drainage schemas on Earth. Over the past decade, images from the Mars world(a) Surveyor, which has been orbiting Mars since 1997, turn over revealed spectacular examples of extremely littler and seemingly young gullies formed in the walls of some craters and canyons. These observations indicate the past presence of liquid weewee on the Martian surface or just below it save not necessarily for long periods (Bell 2006). The wet from the catastrophic floods, for example, whitethorn check lasted only a few days or weeks on the surface before freezing, seeping back into the primer or evaporating.Furthermore, the networks of river-like valleys shown in the Viking orbiter images do not have the uniform characteristics as terrestrial river valleys when seen at high er resolution (Bell 2006). The Martian valleys could have formed entirely from submarine water flow rate and ground corroding 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 firmly prove that the carmine Planet once had a smoke, wetter, more Earth-like environment with long-lasting lakes and rivers.In the past few years, however, bracing satellite images have provided much more convincing evidence that stable, chromatic 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 Cra ter 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 and show varying degrees of erosion. To many geologists, this feature has all the characteristics of a delta that formed at the end of a bank deposit-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 by and large from subsurface flow, these sorely found networks have characteristics that are consistent with their organization by rainfall or snowmelt and surface runoff. For example, the networks are arranged in dense, bifurcate patterns, and the lengths and widths of the valleys increase from their sources to their mouths. Moreover, the sources are located along the ridge crests, suggesting that the landscape was work by precipitation and runoff. Indeed, these landforms provide the best evidence to date that it may have rained on Mars.A more exploratory possibility is that these runoff features arose comparatively recently, perhaps one billion to 1.5 billion years after Mars formed. To estimate the ages of Martian landforms, researchers count the number of impact craters on the feature the more impacts 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 tierce of the planets history a nd perhaps longer if even younger valleys are finally identified.Yet another piece of evidence supporting persistent liquid water on Mars is the observation of truly enormous amounts of erosion and deposition 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 gnaw in the first billion years of the planets history may have been about a million times as high as the present-day(prenominal) rate (Bell 2006).But what process could have merchant vesselsed 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 repeatedly during Marss primal 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 addition 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 clays or other oxidized, hydrated phases (minerals that incorporate water molecules or hydro xide ions in their crystal structure).The emerging paradigm is that Mars had an extensive watery past puddles or ponds or lakes or seas (or all of them) existing for long periods and exposed to what must have been a thicker, warmer automatic teller machine. 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 personal manner to sulfates as the acid rain (of sorts) continued to alter the volcanic rocks and dampen down any carbonates that may have formed earlier. Over time, the atmosphere thinned out perhaps it was lost to space when the planets magnetic issue shut off, or maybe it was blown off by catastrophic impacts or sequestered somehow in the crust. Mars eventually became the cold, arid pl anet recognized today.This new view of Mars is not even so universally accepted, however. Key suspicions 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 scoured 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, come to the fore 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