Earth viewed from space reminds of us of our own fragile world
PUBLISHED: 08:52 16 February 2020 | UPDATED: 08:52 16 February 2020
Matt Bailey, a professionally-qualified engineer with a deep interest in technology and humanity recalls a groundbreaking photo 30 years on
On Valentine's Day 1990, NASA's Voyager 1 spacecraft looked back at our solar system from its farthest reaches and captured the most extraordinary selfie ever taken - an image of Earth, apparently no bigger than a mote of dust, suspended in a ray of sunshine. Almost as memorable as the photograph were the words at the time of Cornell professor and broadcaster, the late Carl Sagan, who was moved almost to tears as he regarded the image. If you don't already know Sagan's Pale Blue Dot speech, I urge you to Google it. It is perhaps the most poignant lecture ever delivered in so few words.
"Our planet is a lonely speck in the great enveloping cosmic dark," he says. "That's here. That's home. That's us."
In 1979, two years after Voyager 1 began its journey into eternity - and 11 years before the famous selfie, Sagan co-wrote and presented an epic 13-part TV documentary called Cosmos, in which he contemplated the origins and the immensity of the universe, the wonders of the solar system and the possibility and likelihood of extra-terrestrial life. The show was a huge success, on both sides of the Atlantic, due in no small part to the host's ability to communicate easily, complex and fascinating concepts.
In the first episode, Sagan used the familiar Roman calendar to illustrate the enormity of time since the universe was formed, during what astrophysicists refer to as the 'Big Bang,' 15-billion years ago (since adjusted to approx. 13.8 billion years). He asked his audience to imagine that each month, from January to December, was equivalent to approx. 1.25-billion years. Each day, using this scale, is "worth" some 40-million years, and each second, 500 years.
Sagan went on to explain that if we imagine that the cosmos began on January 1, it was in May that the Milky Way was born and September when our sun and the Earth were formed. Early life, he explained, began soon after, but the first humans only appeared on the cosmic scene sometime around the penultimate day of the year.
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It wasn't until December 31st at 11:59 and 20 seconds, however, that humankind applied its ability to make and use tools, organised itself into societies and built cities. "We humans appear on the cosmic calendar so recently," said Sagan, "that our recorded history occupies only the last few seconds of the last minute of December 31."
The first, primitive hand-tools were used in Tanzania, East Africa, and remnants found by archaeologists have been dated at around 2 million years. Using Sagan's scale, all of the accoutrements and conveniences of our industrial age, including passenger aircraft, motor vehicles, domestic appliances, computers, medical devices, space craft, satellites and nuclear power stations - as well as all their concomitant by-products and pollution, have been created in the last seconds before the clock strikes midnight on the cosmic New Year's Eve, where we live now.
When Sagan recorded his series, the world had a stockpile of 50,000 nuclear warheads, collectively capable of destroying every city on the planet several times over. Thankfully, by the time Voyager 1 took the photograph of The Pale Blue Dot, the Iron Curtain had fallen and the world's arsenal of nuclear weapons had been reduced dramatically.
The nuclear arms race is, we hope, forever behind us. But, unless we as a species find better, cleaner ways to engineer and manufacture the many things we take for granted - and better, safer, more sustainable ways to produce the energy our growing global population needs to survive, we are still at risk of what came to be known in the Cold War era as Mutually Assured Destruction (M.A.D).
Referring to the looming threat of a nuclear holocaust, Sagan reminded his viewers: "We are the legacy of 15-billon years of cosmic evolution. We have a choice: We can enhance life and come to know the universe that made us, or we can squander our…heritage in meaningless self-destruction."
To paraphrase his conclusion, how we treat the Earth in the last few seconds of this cosmic year - and what we do to rectify the mess we've made so far, will decide what happens as the clock tolls 12 on our wasteful and profligate habits.
Perhaps in the week of Valentine's Day 2020 it's a good time to take another look at The Pale Blue Dot and decide what we can do to show Earth how much we love her.
Beautiful, small and fragile; the only home we have.