A Tale of Three Planets

Later this month Mars will be in opposition relative to Earth and the Sun. It will also be making its closest approach to Earth since 2003. As a result, the Red Planet will cut an impressive presence in our night sky. In recent decades, Mars has regained something of the stature it once commanded in the human imagination. There is renewed talk of human exploration and interest in the search for life. It is a recovery that has been a half-century in the making.

For the first half of the twentieth century, Mars provided a focus for the human imagination as the setting for a sort of astral Arabian Nights - the Barsoom of Edgar Rice Burroughs with its myriad of (usually warring) species or the home of H.G. Wells' (and later – over the medium of radio - Orson Welles') malevolent, tentacled invaders. 

While early twentieth century writers embarked on flights of fancy, contemporary scientists postulated as to the actual nature of conditions on the Red Planet - a world which appeared to Earth-bound observers to exhibit dynamic characteristics all its own. Periodic color changes on Mars' surface hinted at seasonal variations of vegetation - which meant complex life. Some observers interpreted marks across the planet's surface to be waterways. Others went a step further and presumed an "apparent" linearity to those features thus implying artificial construction - which meant intelligent life. For a moment, science and art moved in tandem. 

Then came 1965 - the year of the Mariner 4 flyby.

Mariner 4's all too brief encounter (1% of the surface) obtained the first, close-up photos of the Martian surface. The images showed not resilient vegetation along watercourses but revealed a crater-strewn surface not unlike that found on Earth's all too familiar, lifeless Moon. All of a sudden, Mars was, in the minds of many, reduced to merely a larger, more distant version of Earth’s Moon.

The Martian bubble burst. With it, the impetus for manned exploration (then proposed for the mid 1980's or even earlier) faded by the wayside. Even Mariner 9's orbital survey starting six years later and which provided evidence of a much more varied landscape - even with evidence of past liquid water - failed to restore the Red Planet's aura.

But what if, during that initial 1965 flyby, Mariner 4 had captured some the more fascinating landforms discovered by later probes? What if, instead of the moon-scape image seen above on the left from Mariner 4, observers had been treated to views more like that on the right? Or even to a glimpse of the feature which became known as the "Face" of Mars? 

Could a difference of a few thousand kilometers in Mariner 4's ground track have been a game changer affecting the course of human exploration of the Solar System? Might we be today sitting on Mars (or beyond) ruminating about the unpleasant consequences had the first probes returned images suggesting a bland, dead world?