Wednesday, June 23, 2010
The areas in the Solar System that have the greatest chance of life are Venus, Mars, Europa, Titan, and Enceladus. Sometimes Ganymede and Callisto are also mentioned but it's the first five that are the most interesting. In spite of this the lion's share of interest is devoted to Mars, and interest in Venus is strangely lacking in spite of how easy it is to investigate.
First let's take a look at this chart I made:
This is a rough but generally accurate chart of the amount of interest in life in these areas compared to the ease of exploration. Interest reflects the number of instances found when doing a search, giving:
- "Life on Venus" - 113,000 results
- "Life on Mars" - 2,830,000 results
- "Life on Europa" - 14,200 results
- "Life on Enceladus" - 10,500 results
- "Life on Titan" - 48,300 results
- Distance to Venus - 38,000,000 km
- Distance to Mars - 54,600,000 km
- Distance to Europa - 634,000,000 km
- Distance to Enceladus and Titan - 1,196,000,000
1) we still don't know exactly what these missions to investigate life would be in the first place, and
2) though Delta-v is what one needs to calculate in order to determine the fuel required to reach a destination, distance is still important in that quicker communication with a probe is a large benefit (the longer communication takes the more advanced AI the probe needs to have) and also that a probe that fails on the way to Venus for example can be redone in a relatively short time, whereas a probe that malfunctions one week before arriving at Saturn (one shudders at the thought) more or less means the end of exploring that part of the Solar System for at least a decade.
Also keep in mind that the probes we would need to investigate the areas on Venus that could contain life (the cloudtops some 50 km above the surface) would be even easier to construct given that they need no landing gear. A simple solar flyer as proposed by Geoffrey A. Landis or a balloon like those the Soviets sent in the 1980s (though longer lasting) might suffice.
So, back to the chart: since we have yet to investigate any of these locations, ideally interest in them should be roughly equivalent to the ease in exploring them and finding out. That is, since Venus is the closest and easiest location in which to look for life we should ideally be most interested in finding out whether it exists there. If not there, then time to check out Mars, and so on. Europa and Enceladus are probably exceptions to this since we know they have massive oceans underneath their surfaces and this in and of itself is fascinating whether life exists there or not.
In other words, the world should be at least one or two dozen times more interested in the possibility of life on Venus than it is. It's the closest destination to us besides the Moon, and a craft can be sent there for a relatively low cost to investigate, just a few hundred million. For all we know Venus has life, right now, the descendant of life that existed there and once flourished on the surface and everywhere else billions of years before and is even now still managing to maintain a tenuous grip in the clouds above the once paradisaical, now hellish world. And yet interest is scarce. Why?