Tuesday, September 14, 2010

Fresh views inside the mare crater pits

Updated September 16, 2010 1958 UT
Spectacular high Sun view of the Mare Tranquillitatis pit crater reveals boulders on an otherwise smooth floor. Image is 200 meters wide, north is up, NAC M126710873R (400 meter-wide original LROC Featured Image, HERE.) [NASA/GSFC/Arizona State University].

Mark Robinson
Principal Investigator
Lunar Reconnaissance Orbiter Camera
Arizona State University

When the Sun is well overhead, the floor of the Mare Tranquillitatis pit is illuminated. With an incidence angle of 26.5° and a shadow of 55 meters, scientists can estimate the depth to be a bit over 100 meters. That estimate is from the edge of the shadow, which begins a slightly downslope from the gradual margin of the pits. When measured from the level of the surrounding mare plain, the depth of the pit is even greater. Compare this depth to the width, which ranges from 105 to 115 meters across the sharp precipice.

Two views of Mare Ingenii pit [NASA/GSFC/Arizona State University].

A pair of Mare Ingenii pit images (each panel is 150 meters wide) reveals different portions of the floor as the Sun crosses from West to East (Left M123485893RE, Right M128202846LE). Shadow measurements indicate that the Ingenii pit is about 70 meters deep and its width is about 120 meters. The Sun angle, direction, and elevation perfectly illuminate the layered nature of the mare basalts. Each shelf corresponds to a local lava flow event. By climbing down this "staircase" a geologist astronaut can sample increasingly further back in time.

Variations in lighting reveal the structure of the fascinating lunar pit craters. The center panel, with the Sun high above, gives scientists a great view of the Marius Hills ("Haruyama") pit interior. Each panel is a 300 meter-wide section of LROC NAC observation; top M133207316LE, center M122584310LE, bottom M114328462RE See original three-panel view, HERE [NASA/GSFC/Arizona State University].

LROC has now imaged the Marius Hills pit three times, each time with very different lighting. The center view has an incidence angle of 25° that illuminates about three-quarters of the floor. The Marius pit is about 34 meters deep and 65 by 90 meters wide. Read more about the Ingenii, Tranquillitatis, and Marius pits.

Do any of these pits provide access to still-open/uncollapsed lava tubes? What could be learned by visiting and exploring one or all of these fascinating features? Imagine entering a preserved lava tube, unchanged for more than 3 billion years; such an opportunity is a geologist's paradise - a chance to travel back in time to see what brand-new lava flows look like! What types of rare minerals might exist on these hidden surfaces (if they exist)? Do you think we should send a robot into one of the pits? How about astronauts; is it worth sending humans in to explore? How would you like to explore this amazing feature?

Search the nearby area for clues in the full LROC NAC frame that may help determine if an extended lava tube system still exists beneath the surface.


Anonymous said...

Hi Joel,

This is why i come to LunarPioneer.
You broke the news to me when the Marius hole was discovered.
You wrote:
"How would you like to explore this amazing feature?"
It would be really exciting for the first few weeks. Then one realizes how vulnerable one is and how bleak and lonely is the moon. Filled with anxiety one hopes his equipment holds up and that plants in his greenhouse survive. Really, it would be less enjoyable than the
Shackleton Expedition to Antarctica.

Joel Raupe said...

Less enjoyable than the Shackleton expedition? At least everyone survived, though I can't remember whether the dogs made it back. We spent valuable time tossing this back and forth today. You raised an interesting point. Is our imaginary visitor, as they look into the the "Marius Hole," tourist or a pioneer?

This is an important distinction, because it is safe to say, among those few who would dare to consider an actual and personal trip off planet, there are probably even fewer who would want to stay. Even fewer could withstand rigorous training or tests to find out if they are physically and mentally fit.

(Many would consider anyone's having a desire to stay on the Moon as proof enough of a lack of mental fitness, a real "Catch-22."

But something needs to be said about such prospective pioneers and what we have learned about such people from history, and not from legend and most science fiction. Because, very soon we are likely to run into an inevitable problem in human behavior many have failed to consider. Most pioneers come out from social orders where they consider themselves unfit and especially beyond redemption.

On the other hand, those thought of as most fitted for space colonization are the least likely to truly Pioneer, a generally alien and unheralded work almost always requiring a removal of themselves from familiar, happy surroundings, their extended families and cultures, habits and customs. The comfortable don’t change positions.

Successful, happy people, or those who think they have a shot at being successful or happy, don’t generally emigrate. So, we have a problem, and it is a problem some think too difficult to solve, though we are not among those who hold such a view.

A better outline of this problem is found in the books and aphorisms of the San Francisco

longshoreman and noted 20th century philosopher Eric Hoffer, particularly in his book, The Ordeal of Change, " and also touched on more directly in the more dynamic context presented in his more famous work "The True Believer."

"Pioneers take the arrows," as they say, but not because such people are generally more particularly suited to the task mentally of physically. Most who "Pioneer" do so because they are compelled to in a fashion indistinguishable from being forced, and they succeed because there's no other choice.

Permanently colonizing the Moon, Mars and beyond will require people many consider at least a little "odd," in one way or another. It will require many among these "odd" people who have concluded that they, themselves, are irredeemably maladaptive, usually socially. Those saddled with that most dreadful of modern conditions: low self-esteem.

Anonymous said...

"...Moon, Mars and beyond will require people many consider at least a little "odd," in one way or another. ...people who have concluded that they, themselves, are irredeemably maladaptive, usually socially."

Well put in quotes. Values like odd, maladaptive, low self esteem only apply if there are others around to compare them to.

Pressure to conform destroys ingenuity.

There are people who need solitude; their minds uncluttered by how they rate with others. Their traits become a positive in a bleak situation; focused only on where the next pound of air, water or food will come from.

In tribal times they would have been cowboys, shepherds, hunters, fishers; away from people mostly.

Best if they volunteer, are paid and have some prospect of return though. Shackelton offered as much.
Coerced people may sabotage the colony & themselves out of desperation.