Tag: Voyager 1

A Letter to the Moon

We live on such a fragile planet!

The idea of writing a letter to the moon is not a new one and it came to me when listening to an item yesterday morning, Pacific Time, broadcast by the BBC on Radio 4. The item was the news that Elon Musk has announced that:

Elon Musk’s company SpaceX has unveiled the first private passenger it plans to fly around the Moon.

Japanese billionaire and online fashion tycoon Yusaku Maezawa, 42, announced: “I choose to go to the Moon.”

The mission is planned for 2023, and would be the first lunar journey by humans since 1972.

So here is that letter!

ooOOoo

Dear Mr Moon,

I cannot believe how quickly the years roll by!

Who would have thought that yesterday, the 18th of September, 2018, was the anniversary of the day in September, 1977 when:

On September 18, 1977, as it headed toward the outer solar system, Voyager 1 looked back and acquired a stunning image of our Earth and moon.

You will surely remember that first image taken of the Planet Earth and your good self in the same frame.

Here is the 1st-ever photo of the Earth and moon in a single frame. Voyager 1 took the photo on September 18, 1977, when it was 7.25 million miles (11.66 million km) from Earth. Image Number: PIA00013 via NASA/JPL.

Now here we are some 41 years later and, my, how things have changed.

But something, dear Mr. Moon, has never changed for you. That is the sight of our most beautiful planet. Plus, I would go so far as to venture that what makes our planet such a beautiful sight, one that has captivated us humans when we have gone into space and looked back at home, is the magic of our atmosphere.

It is so thin!

Picture taken by a NASA satellite orbiting the earth some 200 miles above the planet’s surface.

So, so thin …. and so, so fragile.

It is akin to the thinness of the skin of an onion.

In fact, Mr. Moon, that layer that we earthlings call the troposphere, the layer closest to Earth’s surface varies from just 4 miles to 12 miles (7 to 20 km) thick. It contains half of our planet’s atmosphere!

Everything that sustains the life of air-breathing creatures, human and otherwise, depends on the health of this narrow layer of atmosphere above our heads. Now the thickness of that layer varies depending on the season and the temperature of the air. But let’s use an average thickness of 8 miles (say, 13 km) because I want to explore in my letter to you some comparisons.

In your infinite gaze down upon your mother planet you will have seen the arrival  of H. sapiens, out of ancestral H. erectus, that took place roughly 315,000 years ago.

You will also have seen from your lofty vantage point the growth of both CO2 levels in the planet’s atmosphere and the average land-ocean temperature. Forgive me quoting something at you, but:

OBSERVABLE CHANGES IN THE EARTH

SINCE THE INDUSTRIAL REVOLUTION

While politicians have been busy debating the merits of climate science, the physical symptoms of climate change have become increasingly apparent: since the industrial revolution, sea level has grown by 0.9 inches, the atmospheric concentration of carbon dioxide has risen to unprecedented levels, average global temperatures have increased by about 1.0 degree Celsius and, to top it off, the global population has jumped by nearly 600 percent; 15 of the 16 hottest years on record occurred in the 21st century, and 2016 is likely to be the warmest year ever recorded.

Now the Industrial Revolution was all but over back in 1840 and the last 178 years have seen an explosion in the way we use energy, in all its forms. Plus we have to accept that back then the global population was around 1 billion persons. It is now over 7 billion.

Between 1900 and 2000, the increase in world population was three times greater than during the entire previous history of humanity—an increase from 1.5 to 6.1 billion in just 100 years.

So on to my comparisons.

The radius of our beautiful planet is about 3,959 miles (6,371 km). The average thickness of the troposphere is 8 miles (13 km).

Thus the ratio of thickness of our liveable atmosphere to the radius of the planet is 8 divided by 3,959. That is a figure of 0.002! Our atmosphere is 1/1000th of the size of the radius of our planet.

Hang on that figure for a moment.

In the last 178 years humanity has transformed our consumption of energy and especially carbon-based fuels. H. sapiens has been around for 315,000 years.

Thus the ratio of these present ‘modern’ times (the last 178 years) to the arrival of us back then (315,000 years ago) is 178 divided by 315,000. That is a (rounded) figure of 0.0006. Our modern times are just 1/10,000th of the time that so-called modern man has been on this planet.

So, dear Mr. Moon, you must despair that in so short a number of years, proportionally ten times smaller than the ratio of the troposphere to the radius of our planet, we funny creatures have done so much damage to what we all depend on to stay alive – clean air!

Or maybe, my dear companion of the night sky, because you are celebrating your 4.1 billionth year of existence, what we humans are doing is all a bit of a yawn.

Sincerely,

This old Brit living in Oregon.

ooOOoo

My dear friends (and I’m now speaking to you dear reader, not the moon!) when you reflect on the fragility of our atmosphere, well the layer we depend on for life, you realise without doubt that each and every one of us must make this pledge.

“I promise to do everything possible to reduce my own personal CO2 output and to ensure that both to my near friends and my political representatives I make it clear that we must turn back – and turn back now!”

Or, as George Monbiot writes in closing a recent essay (that I am republishing tomorrow): “Defending the planet means changing the world.”

and it’s so insignificant!

Yesterday’s post It’s all we have showing the famous Earthrise picture taken from Apollo 8 generated a lovely follow-up.

One of the comments was from Mike Turner who wrote,

It’s all we have and it’s so insignificant!

The Pale Blue Dot

Mike included a link to an entry on WikiPedia about the tiny, small dot of light in the universe that is Earth, shown in a photograph taken by spaceship Voyager 1 from the edge of the Solar System on February 14th, 1990.  Here’s that photograph,

Planet Earth from 3,762,136,324 miles

Can you see our planet home?  Earth appears as a tiny dot (the blueish-white speck approximately halfway down the brown band to the right) within the darkness of deep space. In a 2001 article by Space.comSTScI‘s Ray Villard and JPL‘s Jurrie Van der Woude selected this photograph as one of the top ten space science images of all time.

Carl Sagan later wrote about his deep feelings about this photograph.  That was almost 20 years ago and, as I reflected just a few days ago, human insanity still seems alive and well; it’s about time that the majority of us recognised the fragility and vulnerability of where we live.

Sagan’s words are reproduced here and should be read by every inhabitant of this planet.

From this distant vantage point, the Earth might not seem of particular interest. But for us, it’s different. 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. [my italics, Ed]

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.

You may also wish to watch this video.

Thanks Mike for prompting this piece.