Two early images of Earth that bolstered the environmental movement

April 22, 2020 marks the 50th anniversary of Earth Day. A half a century ago, when Earth Day was established, two iconic images of the Earth were taken that changed humanity's perspective on itself, and helped launch the environmental movement, yet both pictures were unplanned.

In 1968, Apollo 8 was the first mission to carry humans beyond the gravitational realm of the Earth and commit them to another heavenly body, the moon. Jim Lovell, Bill Anders and Frank Borman did not land on the moon, but they were the first to make the journey, placing themselves into lunar orbit on Christmas Eve then returning home after ten orbits.

Their job was to test out some of the technology for lunar exploration and take close up photographs of the lunar surface to help choose future landing sites.

It was not until their fourth time around the moon, when their command module just happened to be facing in the right direction, that they saw something human eyes had never seen before, the small blue and white sphere of the Earth rising above the lunar horizon.

The astronauts were both surprised and amazed at the scene and scrambled to take a picture.

And with that, Bill Anders took the famous Earthrise picture, the first handheld colour image of our planet as seen from another world.

As Frank Borman joked, it was not scheduled, yet it became the most iconic image of the time, the Earth floating in an immense blackness, hovering above a totally hostile, airless alien horizon, appearing so small it could hide behind your thumb.

That image helped fuel the holistic thinking of our planet as a single living organism that helped spawned Earth Day and the environmental movement.

Yet another unplanned iconic Earth image taken in space

The second image was taken during Apollo 17, the last mission to the moon in 1972, and has been dubbed the "Blue Marble," because it was the only one taken of the Earth when it was fully illuminated.

The photo was taken at the very beginning of their mission when they had just left Earth orbit and were about 29,000 km away. (Astronauts today aboard the International Space Station do not see the entire Earth because the station is only 400 km up. The 24 Apollo astronauts who went to the moon were the only humans to see the whole Earth.)

Again, this image wasn't taken during a time when they were scheduled to take photographs, but the beautiful Earth appeared in the spacecraft window and they couldn't resist getting a shot.

There is a debate about who actually took the photo because upon their return, the three crew members, Eugene Cernan, Harrison (Jack) Schmitt and Ron Evans all claimed to have taken it. NASA credits the entire team.

The Blue Marble photo of the Earth became the poster child of the environmental movement, one of the most requested images in the NASA archive. But it is more than another reminder of the frailty of our planet, it is a metaphorical look back to the origins of our technology.

Blue Marble image highlights the African continent

The photograph is dominated by the continent of Africa, where the remains of all our human ancestors have been found. It was there that our predecessors stood up on two legs millions of years ago and began a journey that would eventually cover the globe.

Near the centre of the photo, partly hidden by clouds, is Tanzania, and a place called the Olduvai Gorge, where in the early 1960s Louis and Mary Leakey found the remains of Homo habilis, who were among the first stone tool makers more than two million years ago. 

How poetic it is that the last picture of the full Earth taken by hand is looking back to where handheld tools originated. We have come a long way in two million years. It is totally appropriate that the Blue Marble represents the environmental movement because it is our tools that have changed the face of the planet. 

As we celebrate the 50th anniversary of Earth Day, we can look forward to applying the same science, engineering and technology that raised humans high enough off the planet to look back on the Earth, to mitigate the impact of our tools and develop better tools in the future to keep the planet blue.