On 23 January, 1960, the bathyscaphe Trieste propelled Jacques Piccard and Don Walsh to the bottom of Challenger Deep in the Marianas Trench, which at more than 10,900m (35,800ft) down is the deepest spot in the ocean.BBC has a report on both the amazing (and extraordinarily dangerous) events of 50 years ago today, and the marine biology that is currently being carried out in oceanic trenches around the world. The lead graphic has a number of embedded videos, about a minute to minute-and-a-half each, which I watched yesterday, but I didn't get around to reading the article until just a moment ago.
I don't feel the same wistfulness about our apparently lack of a modern "manned deep-sea exploration program" as I do about our lack of a manned deep space program. A life support failure in the trench environment would kill people even faster than a similar breach in space. So not only is putting a person in that environment extremely difficult and expensive, it's unnecessarily risky. And while the logistics of sample retrieval are not trivial, neither are they outrageously difficult. The bottom is, at a maximum, 10 or 11 km away from the surface. For biological purposes, studying the fauna in situ makes more sense anyway.
On the other hand, consider the following image of a rock on Mars, posted today at Red Orbit, which I set aside earlier with the idea of posting it as the "Frustrating Rock Photo of the Day."
NASA's Mars Exploration Rover Opportunity examined a rock called "Marquette Island" from mid-November 2009 until mid-January 2010. Studies of texture and composition suggest that this rock, not much bigger than a basketball, originated deep inside the Martian crust. A crater-digging impact could have excavated the rock and thrown it a long distance, to where Opportunity found it along the rover's long trek across the Meridiani plain toward Endeavour Crater.(Click here for full size) A second with a rock hammer, and one could have both a fresh (unpolished) surface, and a hand sample for a thin section and detailed chemical analysis. I'm assuming this is some sort of peridotite or eclogite, and I assume that this conclusion was reached on the basis of chemical analysis that the rover carried out. Why frustrating? I'd love to know more about the Martian mid crust, and this picture tells me next to nothing. It's coated with dust, so I can see neither mineral grains nor textures. There seems to be a faint fan-shaped lineation from the lower right of the sample to the upper left, which suggests a shatter cone. That would be consistent, but without the ability to turn it for differing illuminations and a three dimensional perspective, the pattern is so faint that I'm not really confident in my observation. How would this compare to rocks from a similar position in the earth's crust? How would it differ? So many questions! And all I have is a danged photo, which tells me next to nothing about this rock.
So is it more important to learn more about the deepest ocean floor or about rocks on Mars? That's the totally wrong question: it's important to learn about both, and it's impossible for me to objectively rank which one is "more" important. This amazing universe in which we find ourselves is worthy of trying to comprehend... whatever it takes. If it can be done effectively with remotely operated vehicles, that's super. If not, send a person.