NASA's tips for revisiting lunar landing sites (someone at NASA has a sense of humour)

Last week I read a document called NASA's Recommendations to Space-Faring Entities: How to Protect and Preserve The Historic and Scientific Value of U.S. Government Lunar Artifacts.

Scientists at NASA wrote the 93-page tome due to interest by new organizations in visiting the moon. Some nations like China and the U.S. are planning lunar missions, but there's also private interest. For instance, the Google Lunar X Prize has 26 teams competing to get a robot to the moon by 2015, have it drive around for 500 metres (or more), and send HD imagery and video back to earth. Winning teams can qualify for $30 million dollars in prizes!

The NASA report - if you can get through all 93 pages - is fascinating. It has all kinds of recommendations for preventing damage to existing moon artifacts. For instance, lunar spacecraft should fly tangentially (aka, beside) existing lunar landing sites instead of over top of them, to avoid kicking up corrosive moon dust or spitting down unburned propellant - either of which could damage the sites and artifacts. Landing too close to a scientific site could cover LRRRs - Laser Ranging Retro-Reflectors - in moon dust. We bounce lasers off LRRRs from the earth and measure how long it takes for the laser to bounce back. This measures the distance between the earth and the moon, and also tests Einstein's Theory of Relativity. These experiments don't work with the mirrors covered in dust!

NASA says that sites of utmost historic importance (Apollo 11 and Apollo 17, the first and last manned visits of the Apollo era) shouldn't be visited at all - they are rightfully considered important milestones for humanity:

"Project Apollo in general, and the flight of Apollo 11 in particular, should be viewed as a watershed in human history and humanity. It was the first instance in human history in which emissaries from this planet visited another body in the solar system. It represented the culmination of years of effort, the significant expenditure of life and resources, and the opening of a new age in human history. The site of that first landing requires preservation; only one misstep could forever damage this priceless human treasure."

NASA says it is permissible to visit the other Apollo sites (12, 14-16). In fact, NASA helpfully supplies a 20-page appendix of items they'd like new moon visitors to study, to determine how they've changed over 40 years on the surface of the moon: thermal paint, gears and dials, bags filled with food and human waste, even the nylon on the iconic lunar American flags. NASA also suggests some experiements, if visitors are so inclined. Here's where they hide their joke (page 52):

"Item J: Push biggest possible rock over edge of crater or rille
Tracks of boulders rolling down slopes have been used to infer geotechnical properties of the surface layer. The large boulder at [lunar site] A17 was sampled because a track implied that it had been part of an outcrop much higher up on the massif. A17 is also the site of an avalanche that is thought to be the result of an (hypothetical) impact on the far side of the massif. Soils that develop on slopes may well be metastable such that avalanches could be easily triggered. Also, it would be fun to push a big rock over a cliff. It is a question whether a rover could push a rock and also observe the descent, but it is worth thinking about." (emphasis added)

Lol, awesome. It's so cool all of this lunar stuff is happening in my lifetime.

NASA Report

Required Reading for Acquiring a Sense of Awe and Wonder at the Universe

1) The 10,000 Year Clock

In a remote Texas desert, work is currently underway to build a 10,000 Year Clock deep inside a mountain that Jeff Bezos (of Amazon.com fame) purchased. Yes, Jeff purchased a huge parcel of land so that the Long Now Foundation - a group formed to foster long-term thinking and responsibility for the next 10,000 years - could design and build a massive, 200-foot-tall clock that only chimes one a year from deep inside a mountain.

The inventor is quoted as saying:

"I cannot imagine the future, but I care about it. I know I am a part of a story that starts long before I can remember and continues long beyond when anyone will remember me. I sense that I am alive at a time of important change, and I feel a responsibility to make sure that the change comes out well. I plant my acorns knowing that I will never live to harvest the oaks." - Danny Hillis

The project page is a fascinating summary of the philosophy and engineering principles behind the clock. For instance, virtually all modern methods of generating power - wind, solar, nuclear, chemical, geothermal, connection to electrical grid - become unsustainable over 10,000 years. So what's the best method to power the clock? Human interaction.

"To see the Clock you need to start at dawn, like any pilgrimage. Once you arrive at its hidden entrance in an opening in the rock face, you will find a jade door rimmed in stainless steel, and then a second steel door beyond it. These act as a kind of crude airlock, keeping out dust and wild animals. You rotate its round handles to let yourself in, and then seal the doors behind you. It is totally black. You head into the darkness of a tunnel a few hundred feet long. At the end there’s the mildest hint of light on the floor. You look up. There is a tiny dot of light far away, at the top of top of a 500 foot long vertical tunnel about 12 feet in diameter. There is stuff hanging in the shaft."

Once built, the clock will store enough mechanical energy to keep accurate time for the next 100 centuries, thanks to a gear mechanism and 10,000 pounds of hanging man-made stones. A solar alignment mechanism ensures the clock keeps correct time based on the alignment of the sun. However, if the clock is to sound a chime every year, humans (at least two or three) will need to make the pilgrimage to the clock to wind up the 10,000 pound weight.

The physical scale, timeframe of the project and forward-thinking engineering are astounding and they leave me in awe. This is absolutely a place I want to visit and participate in during my lifetime. The 10,000 Year Clock is our current civilization's mark on the future; it's our Pyramids of Giza, our Colosseum, our Great Wall of China.

Read more: http://longnow.org/clock/

2) Wikipedia's Timeline of the Far Future

While reaching about the 10,000 Year Clock, I stumbled across a Wikipedia page that summarized events that physicists, geologists and astronomists theorize will occur anytime between 10,000 years in the future and 1 trillion years in the future - and beyond.

For instance:

In 50,000 years, Niagara Falls will have eroded away the 20 miles of land to Lake Erie and will cease to exist. Also, the earth is projected to go into another natural ice age at this point, if humans don't have an effect on the atmosphere (which we know to be incorrect).

In 500,000 years, odds are sound that the earth will have been impacted by a meteorite of roughly 1km in diameter.

In 11 million (11,000,000) years, the moon Phobos will collide with the surface of Mars.

In 5.4 billion (5,400,000,000) years, the sun will become a red giant. This will destroy Mercury, Venus and possibly Earth (although it is certain that if Earth isn't destroyed, it will certainly not be habitable by this point).

In 50 billion (50,000,000,000) years, the Moon and the Earth (assuming they still exist in their present states) will become tidelocked, with each only showing one face to the other.

In 10^1500 (10 to the power of 1500 - this is a 1 with 1,500 zeros following it) years, all matter in the known universe will have decayed to the element Iron-56 (assuming proton decay doesn't exist, which we don't know yet).

When you examine our individual lives on the universe's grand scale of time, we wink in and out of existence so fast that ultimately we have no effect whatsoever on the universe's final fate. If you combine the last 40,000 years of human history with the next 40,000 (and however far we make it into the future), humanity will still have no effect on the universe. Absolutely incredible and unbelievable.

I don't find this the least bit depressing - in fact, it fills me with a sense of awe and wonder. We exist thanks to a series of extremely unlikely cosmic coincidences and I think it's a wonderful way to think about life: we're here, let's fill our lives with things we love and enjoy it while it lasts.

Read more:
Timeline of the Far Future
Graphical Timeline (of the universe) From Big Bang To Heat Death