Mars Global Surveyor has clicked some very exiting pictures on Mars. They reveal a fan-shaped apron of debris. Scientists are analyzing the pictures to make out whether Mars had long-lasting rivers or just brief, intense floods.
They have inferred some of the curves as traces of ancient meanders made in a sedimentary fan as flowing water changed its course over time. "Meanders are key, unequivocal evidence that some valleys on early Mars held persistent flows of water over considerable periods of time," said Dr. Michael Malin of Malin Space Science Systems, San Diego. "The shape of the fan and the pattern of inverted channels in it suggest that it may have been a real delta, a deposit made where a river enters a body of water” he said. "If so, it would be the strongest indicator yet that Mars once had lakes.”
Presence of water on Mars is great news for space scientists. We have been going to space for nearly 40 years now, but it has always been for temporary stays in orbit. Scientists are now looking forward to make Mars a permanent place to stay. Presently, the environmental conditions on Mars are not suitable for life form to survive. Harsh conditions like high and low extremes of atmospheric temperatures and pressures, lack of free oxygen and liquid water, high concentrations of toxic gases, and deadly radiation levels will make it impossible for any life form to survive on Mars. However, in spite of all these harsh conditions, Mars is still a biocompatible planet. Its unalterable physical characteristics (e.g. size, density, gravity, orbit, rotation rate, incident sunlight) and its possible chemical resources are remarkably dependable for life. And although it is a cold, dry planet today, it holds all of the elements that are needed for life to exist.
Unique features of Mars have charmed scientists for a long time. Many have come up with fascinating ideas for changing the environment on Mars into something similar to that on earth. Earth too at one time was not hospitable to life, yet now thanks to evolution, it houses abundant life; couldn't we alter and accelerate the evolution of another planet so that it too could support life?
The process of engineering an extraterrestrial planetary environment to support life is called Terraforming. Although terraforming Mars would be a lengthy and expensive project, there are some innovative technologies and ideas that could make the process feasible. A genetically engineered plant, for example, could self-propagate and convert the carbon dioxide in the Martian atmosphere into oxygen. Greenhouse gasses could be generated to raise the surface temperature making Mars more hospitable. Other theorists claim that huge mirrors made out of thin mylar could be positioned to reflect sunlight to warm small regions of Mars.
Space scientist Christopher McKay and Robert Zubrin, have proposed a more radical method for greenhousing Mars. They have visualized that hurling large, icy asteroids containing ammonia at the red planet would produce tons of greenhouse gases and water. They propose nuclear thermal rocket engines to be somehow attached to asteroids from the outer solar system. The rockets would move the asteroids with high speed toward Mars. Energy released upon impact would be about 130 million megawatts of power.
The energy of one impact would raise the temperature of the planet by 3 degrees Celsius. The sudden raise in temperature would melt about a trillion tons of water stored in the polar caps of Mars. Several of such missions over few decades would create a temperate climate and enough water to cover 25 percent of the planet's surface.
The new Martian atmosphere would be warm and moist, and water would flow again in the dried up river beds. The average temperature at the surface would then rise to about 15 degrees Celsius and the atmospheric pressure would be roughly twice that on Earth. Appropriately selected, or genetically engineered, anaerobic microorganisms, and eventually some plants, could grow under these conditions. Sounds good!
