Life on Mars?

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"Although science may solve the problem of how the universe began, it cannot answer the question why does the universe bother to exist? May be only God can answer that." (Stephen Hawking1988)

The existence of life on Mars has been speculated by many in the past. It is curious that people speculate the existence of Martian beings, but less often about beings in other planets of the solar system. Why is this? Is there a veneer of truth behind all this, that there is life on Mars?

Ever since Giovanni Schiaparelli revealed the presence of canal-like lines on the surface of Mars in the late 19th century, the possibility of civilization on Mars have been strengthen. People believed that the lines seen through the telescope are artificial canals constructed by an intelligent beings on Mars. The Marian phenomenon has became very real.

Following the development of rocket technology, in the 1960s and 1970s human is finally able to send space probes to Mars to have a closer investigation. The results: No intelligent beings, no aliens, nor life. This put a stop to many speculation. Yet, it did not end them all, for the data gathered did not say there was no life on Mars, nor did they deny the existence of life, perhaps in microbial form, beneath the surface of Mars.

Recent discovery of the possible evidence of extraterrestrial microbe in Martian rock sample has renewed speculation that life could once have existed on Mars (and there may still be some now). Though admittedly such so called evidence is not without its controversy and critics.

So what is the probability that there is, or was, life on Mars? Here are some of the fact that pertain to the existence of life on Mars:

1. Evidence of Extraterrestrial Microbe in Martian Rocks.

In August 1996 David McKay and colleagues made the announcement that they have found evidence of past life on Mars. The evidence is based on experiment performed on a 1.9 kilogram Martian meteorite ALH84001 that landed on what is now Antarctica some 13,000 years ago. (It was found in 1984.)

Did the meteorite originate from Mars?

Evidence of life in the meteorite is meaningless if the meteorite did not originate from Mars. The inference that it is from Mars is based on the fact that the distribution of oxygen isotopes, mineralogy and other characteristics are consistent with the measurement performed by the Viking landers (an unmaned spacecraft sent to Mars in 1976, during which it performed, among others, soil sample analysis in Mars.)

Evidence of life?

MacKay alleged that fissures in the meteorite contain carbonate globules, which compositions are shown to contain magnetite and iron sulphide crystals, oily organic molecules, and polycyclic aromatic hydrocarbons (PAHs). These substances are known to be associated with living organisms on Earth. And the presence of these substances together in one place is said to be very good indication that it has a biological source, and hence living things once existed on Mars.

However, not all scientists are convinced. In December two papers, based on independent research done on the meteorite, are published suggesting that the PAHs and magnetite particles can be explained by purely non-biological mechanisms.

I wish and do hope that the evidence is true, but some doubts still linger in my mind. Scepticism is not surprising in that it seems a bit far-fetched, for example, to say that a rock that has been on Earth for 13,000 years has not been contaminated.

While it is not certain whether life exist, or has once existed, on Mars, one thing is clear: there is also no conclusive evidence to say there is no life either. It may be true that the Viking space probe sent to Mars in the 1970s has failed to find the presence life; but this does not mean there is no life on Mars. The experiment conducted by the space probe is based on soil sample collected from a small region on a very big planet. And then the experiment itself may be flawed given our current understanding of biochemistry.

2. Life Sustaining Environment may once have existed on Mars.

Mars may be a frozen and desolate place now, but there are evidence that conditions on Mars have, at some stages, been similar to Earth. The evidence or more accurately hypotheses (since they are often inferences based on indirect measurements or observations) include:

• Temperature in Mars may once have been more hospitable to life as we know it. Variation of Mars’ spin axis and cyclically deviation of the shape of its orbit around the sun in the pass millions of years could explain the once temperate condition and the now frozen condition.

• Possible existence of water and even an ocean in Mars history. Many believed that a large body of water may once have existed on the surface of Mars. Some believed that the water exists in a state of muddy puddle or as small lakes, and some believed in an ancient Northern ocean (duped the Oceanus Borealis). This ocean is supposed to be four times as large as the Arctic Ocean on Earth.

Even now there may still be some water locked deep beneath the permafrost of Mars. Though it seems much of the water has been lost to space. The cause of this is unknown.

Evidence for the existence of water includes: signs of tidal erosion on the landscape of Mars that is reminisce of coastal erosion on Earth, muddy flows surrounding impact crater that suggests the presence of water underneath the surface (perhaps in the form of permafrost), telltale landforms on Mars that resemble "rock glaciers" found in the Alaska Range on Earth, space probe found hydrogen and oxygen atoms (the possible result of the decomposition of atmospheric water molecule by sun) streaming away from Mars.

The best evidence yet is the recent image from the Mars Pathfinder (July, 1997). The initial images of Mars revealed the presence of large boulders stacked against each other in a formation resembling one what would be expected if they were piled up by flood waters, and it was suggested that the crusts on the rocks were formed by sediment and salt from floodwaters as they receded. This suggests the possible existence of a large food., one that is estimated to be big enough to fill the Mediterranean Basin on Earth.

One objection to such claim of a temperate climate or the existence of free flowing water is that Mars’ orbit is too far away from the Sun for the there to be sufficient heat. However, recent calculation indicates that high concentration of atmospheric frozen CO2 (ie. dry ice) would create a variation of the greenhouse effect. Normal gaseous CO2 would not be adequate to warm the atmosphere, but it is different where frozen CO2 are involved. The particles of ice crystals scattered the inferred radiation back to the surface- effectively trapping the heat.

• If these are true that the possibility of an environment that is capable of sustaining and even giving rise to life could well exist in ancient Mars. Indeed, if there once was life, there may still be life on Mars in some form or another.

3. The "Face on Mars"

An image taken in 1976 by the Viking-1 Orbiter revealed a surface feature that resemble a human or ape-like face in the Cydonia region of Mars. And a series of cities or fortress like structure- that look like pyramids on Earth- can also be seen near this "face". This "face" do show a strong resemblance to a humanoid face. This raised speculation that it could be the artificial construction of some alien being, or perhaps even Martian. That is life may have once, and indeed may still do, flourish on Mars (and some even advocate the possibility of life on Mars’ moon, Europa).

There is no conclusive evidence that it is an artificial construction. The official, or NSAS, line is that there is nothing artificial about the structure. (Can we expect anything different from the official?) It is simply the result of natural geological and weather erosion on Mars over the years, or, an photographic illusion created by lights and shadows as seen by the Viking Orbiter. Since the entire data set includes only nine low to moderate resolution photos, there are insufficient evidence to draw any conclusion.

Since the discovery of the face, allegations have been made that it resemble similar structres in Egypt on Earth. Some people claimed that the so called "face on Mars" resemble the Sphinx on Earth (Giza, Egypt). They even claim that their geometric measurement, to the extend that came be ascertain from the photos, which has arguably a large margin of erros, has mathematical significance. Further, non-official analysis of the picture, using well respected scientific analysis and methodology (eg. computer 3-D analysis and fractal analysis), have resulted in the conclusion that the "face" and city-like structure on the surface of Mars does appear to be artificial. Indeed, the similarity to structures on the Giza Plateau in Egypt is undeniable (at least from the photos). This booster the claim on the artificial characteristic of the structure on Mars and also raise the intriguing possibility of alien presence on Earth in the past.

However, this line of argument have been eroded some what by the lastest data from the MARS Global Surveryor. The recent pictures, taken at a higher quality to the previous picture, of the site reveal only ordinary looking hills.

The presence of artificial structure on Mars, if proven beyond doubt, could have great implication for the existence of life in the universe. Afterall, any structure on Mars would have been there for millions of years (compared to the mere 10,000 years or so of the pyramids on Earth). If there are beings technologically sophisticated enough to construct structures on Mars millions of years ago, long before human being have stated to roam the Earth, it makes it more than probable that other life forms also exist elsewhere in the universe.

There may well be a conspiracy that hide the existence of life outside Earth. This is not just limited to Mars. Not only is there alleged to be artificial structure on Mars, artificial structures are also said to be found on our very own Moon!

The debate as to whether there is or was life on Mars will probably continue. No conclusive evidence one way or another is likely until the day when large scale manned exploration of Mars become a reality. Space probe can only do so much (as lease based on current or projected technological innovation in remote sensing technology). Even probe designed to bring back sample of Martian soil cannot be conclusive. How can judgement regarding the existence of life on the whole planet be based solely on a handful of sample!

This said, the current wave of continuing space probe exploration of Mars (half a dozen or so space-probes have been planed up to the year 2005) will undoubtedly reveal more secret of Mars. Now that Mars Pathfinder has successfully landed on Mars, and Mars Global Surveyor about to join it soon, things should start to get interesting. Although their missions are not design to search for life directly; but the data revealed by them will surely shed some light on this matter.

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