Friday, September 5, 2014

An Ode To Cosmos, Comets, and Rosetta Spacecraft

Let's face it.  These days it is rather easy to be pessimistic about the human race and so-called "advanced" societies.  The news is full of reports of wars, terrorism, genocide, religious extremism and sectarian violence, willful ignorance (aka pseudoscience and anti-science), cruelty, environmental degradation, political paralysis, ideological stalemates, economic meltdowns, social incivility, the failure of institutions to provide for the common good, the exploitation and subjugation of women and minorities, etc., etc., etc.  The message is clear:  "Humans are no damn good. Film at 11."

Then, every once in a while something comes along that suggests there may be a glimmer of hope after all.  For me these rare moments are usually associated with (a) acts of extreme unselfishness and compassion that dramatically alleviate suffering or improve life opportunities for people who are desperately disadvantaged, (b) manifestations of artistic or literary talent that produce astonishingly powerful emotional experiences or intellectual insights, and (c) technical or scientific accomplishments that involve supremely focused applications of accumulated human knowledge and logic driven by the irrepressible spirit to know more simply for the sake of knowing.  The last category is the subject of this blog.

The event that has suggested a glimmer of hope to me is the recent success of the European Space Agency's mission to rendezvous with a comet, land a small craft on its surface, and accompany the comet as it approaches the sun. This of course isn't as news-worthy as any of the negative things listed above, but if you examine what it implies about human nature it offers a refreshing and inspiring glimpse of a more positive side of our human potential.

After a journey of 10 years and almost 4 billion miles, on August 6th the spacecraft Rosetta arrived at
Rosetta Probe
its target
, a comet named 67P/Churyumov-Gerasimenko (the name is reason enough not to make it big in the media news).  Although previous spacecraft have flown by comets and have even deliberately crashed into one, this is the first to achieve an orbit around around a comet, the first to study it as it approaches the sun and, if all goes well, the first to soft-land a smaller craft on the comet's surface.  And it's off to a great start, judging by the stunning postcard it sent back to show us it had arrived at the comet.

This is a remarkable accomplishment.  It also adds to a growing list of achievements using unmanned space probes, including the Mars landers, Voyagers 1 and 2,  the Pioneer series, and one of my favorites, Galileo (see my blog, Confessions of a Selective Technophile for more on Galileo).

The Comet 67P/C-G
To put the Rosetta mission in perspective, try to imagine a tiny speck of dust and ice 250 million miles from earth.  From there the sun is a tiny dot, and the light level from the sun is only about 4% what is on earth. The earth looks like most of the rest of the stars, maybe a little brighter. The target speck is only a couple of miles in diameter and traveling at 34,000 miles per hour.  Now imagine trying to send a spacecraft no bigger than a large refrigerator to that icy speck. How would you do it?  How would you find and rendezvous with the speck, given that it is moving 20 times faster than a bullet?  How would you accelerate a spacecraft to 34,000 miles per hour without expending an impractically huge amount of fuel?  How would you communicate with the craft and control it when it is so far away -- so far that radio signals take up to 50 minutes to travel the distance?

The answers to these questions illustrate the extraordinary power of the human intellect  -- they entail a difficult and complex integration of cutting-edge mechanical and electrical engineering, materials science, computer science, applied and theoretical mathematics, astrophysics, astronomy, geology, and many other fields.  Oh, and a huge dose of insatiable curiosity and a relentless drive to explore questions of cosmic significance like "what is the origin of life?"  Humans may not be totally bad...more on this improbable story at 11!

I'll leave a lot of the details to the science reporters (see my embedded links or some of the links below if you want to know more).  I've read a number of them and have marveled at the level of scientific achievement some of my fellow human beings have displayed in this project.  For example, the acceleration problem was solved by looping the Rosetta several times around the earth, using the earth's gravity as a sling-shot to gather speed each time, a technique that took no fuel but added billions of miles and many years to the journey. This acceleration trick has been used previously with other space probes, but never with this much precision.  In this case it was necessary to calculate the exact positions of the spacecraft and the comet as they would be in 10 years, as well as their relative speeds, in order to determine precisely when to fire rockets to slow the Rosetta to match the comet's speed.  Being a bit math-challenged, to me this is a jaw-droppingly awesome feat.

I was a huge fan of the t.v. series Cosmos hosted by the late astronomer Carl Sagan over 30 years ago, in 1980.  Sagan would have loved witnessing the accomplishment of orbiting a space craft around a comet, and would no doubt be making eloquent commentary on the mission. He was not only an accomplished scientist, he was one of the first champions of making science accessible to the general public in an entertaining yet educational way.  The Cosmos series was the first of its kind and highly critically acclaimed -- and it reinforced my lifelong fascination with astronomy and cosmology.  A recent updated version hosted by astrophysicist Neil deGrasse Tyson is a fittingly high-quality successor.  It has the same up-beat, inspiring and humbling effectiveness as the original.

Look very closely.
Sagan wrote a number of popular books on space and astronomy, one of which was titled The Pale Blue Dot, a reference to the earth as it appeared in a photograph taken by the spacecraft Voyager 1 in 1990 as it left our solar system.  Voyager 1 was about 6 billion miles from earth at the time, and the photo is a sobering "selfie" that clearly depicts the smallness of our place in the universe. One often quoted passage in the book is particularly moving to me because it puts our species -- both the positive features and the flaws -- in a very insightful context, and Sage does it in his usual Cosmic style:
Look again at that dot. That's here. That's home. That's us. On it everyone you love, everyone you know, everyone you ever heard of, every human being who ever was, lived out their lives. The aggregate of our joy and suffering, thousands of confident religions, ideologies, and economic doctrines, every hunter and forager, every hero and coward, every creator and destroyer of civilization, every king and peasant, every young couple in love, every mother and father, hopeful child, inventor and explorer, every teacher of morals, every corrupt politician, every "superstar," every "supreme leader," every saint and sinner in the history of our species lived there--on a mote of dust suspended in a sunbeam.

The Earth is a very small stage in a vast cosmic arena. Think of the rivers of blood spilled by all those generals and emperors so that, in glory and triumph, they could become the momentary masters of a fraction of a dot. Think of the endless cruelties visited by the inhabitants of one corner of this pixel on the scarcely distinguishable inhabitants of some other corner, how frequent their misunderstandings, how eager they are to kill one another, how fervent their hatreds.

Our posturings, our imagined self-importance, the delusion that we have some privileged position in the Universe, are challenged by this point of pale light. Our planet is a lonely speck in the great enveloping cosmic dark. In our obscurity, in all this vastness, there is no hint that help will come from elsewhere to save us from ourselves.

The Earth is the only world known so far to harbor life. There is nowhere else, at least in the near future, to which our species could migrate. Visit, yes. Settle, not yet. Like it or not, for the moment the Earth is where we make our stand.

It has been said that astronomy is a humbling and character-building experience. There is perhaps no better demonstration of the folly of human conceits than this distant image of our tiny world. To me, it underscores our responsibility to deal more kindly with one another, and to preserve and cherish the pale blue dot, the only home we've ever known. [My emphasis]
-- Carl Sagan, Pale Blue Dot, 1994
 Right on, Carl. And I hereby dedicate the Rosetta Mission to your vision.

Some Relevant Reference Sources About Rosetta:


Randy said...

Somehow I am reminded of several saying from one of my favorite Chinese Zen Masters - Yunmen:

Having entered the Dharma Hall Master Yunmen said:
“I put the whole universe on top of your eyelashes in one fell swoop.”
“You heard me say this, yet I haven’t the faintest hope that one of you will get all worked up, step forward, and give me a good hard whack. Well, take your time and examine in detail whether you have [the entire universe on your eyelashes] or not! What does it mean?

Master Zen Master Yunmen cited Master Xuefeng’s words:
“The whole world is you. Yet you keep thinking that there is something else.”

The monk inquired, “What is the problem?:
The Master said, “You don’t notice the stench of you own shit.”

Cecilia said...

Thank you for the uplift!