BBC Future

Space Station

Sending postcards for aliens

About the author

Richard is a science journalist and presenter of the Space Boffins podcast. He edits Space:UK magazine for the UK Space Agency, commentates on launches for the European Space Agency and is a science presenter for BBC radio. You can also follow him on Twitter or Facebook.

  • Memorable launch
    Launched in November last year, the Echostar XVI communications satellite carries with it a memorial to humanity. (Copyright: Space Systems Loral and International Launch Services)
  • Earth’s gallery
    Onboard is a 12cm-(5 inch-) diameter disc, within which are one hundred pictures chosen to represent human civilisation. (Copyright: Trevor Paglen)
  • Lasting memory
    Artist Trevor Paglen spent five years selecting the images that would form The Last Pictures project on board the Echostar XVI communications satellite. (Copyright: Trevor Paglen)
  • World view
    Several images show the natural world from different perspectives. (Copyright: Trevor Paglen)
  • Ground control to Major Tom
    Other pictures show our technological advances, such as our ability to send rockets into space like this Russian Soyuz-FG. (Copyright: Trevor Paglen)
  • Greetings from Earth
    Pioneer 10 and Pioneer 11 carried small metal plaques identifying their time and place of origin in case spacefarers might find them. (Copyright: Nasa)
  • Golden record
    NASA placed a more ambitious message aboard Voyager 1 and 2 – a disc with sounds and images aimed at communicating a story of our world to extra-terrestrials. (Copyright: Nasa)
Our space correspondent contemplates the latest effort to preserve humanity’s long-term legacy by sending images into space.

In a billion years time, what will be left of human civilisation?

The pyramids will have long ago crumbled to dust and our technology rusted to nothing. Perhaps we will have found a new life among the stars or reached a higher state of virtual civilisation – especially if the recently announced plans to send a couple to Mars by 2018 come to pass. Maybe Morlocks or apes will rule the planet. The Earth might be a wasteland – destroyed through conflict, environmental catastrophe or the failure to spot an asteroid before it blasts us to oblivion.

But not to worry. Whatever happens to us, something of our legacy will remain – if not on Earth then in space. Around 36,000 km (22,000 miles) above the planet, the long-dead Echostar XVI satellite will continue to orbit, a memorial to humanity. On board, a 12cm-(5 inch-) diameter disc embossed with one hundred pictures representing our civilisation – images of human endeavour, innovation, culture and cruelty; pictures of the natural world and the changes we have brought to it. Or as the artist behind the project, Trevor Paglen, puts it: “A collection of images that will haunt the Earth.”

The Echostar XVI communications satellite was launched in November last year and is designed to remain operational for around 15 years, beaming TV pictures to and from the United States. It is effectively locked in place, in a fixed position, above Earth – its geostationary orbit means that it spins at the same speed that the planet rotates. As with other geostationary spacecraft, its height makes it immune to the drag of the atmosphere. So unlike satellites at lower or higher altitudes, which eventually drift away or plummet to Earth, Echostar XVI will keep its position until it becomes consumed by the Sun.

Paglen spent five years trawling through tens of thousands of images from human history, and talked to artists, scientists, philosophers and campaigners, to select one hundred images that would form The Last Pictures project on board the spacecraft. Scientists at the Massachusetts Institute of Technology (MIT) etched the pictures into an atomically stable wafer of silicon, which was mounted to a golden disc, and then attached to the body of the satellite.

The selected pictures now orbiting above us range from early human cave art to the Earthrise picture captured by the Apollo 8 astronauts during their mission to the Moon. They also include the Great Wall of China, a steam train and an atom bomb explosion. There are also images of soldiers wearing First World War gas masks, caged hens in a battery chicken farm and the tiered benches and bloodstained table of an empty Victorian operating theatre; images where you only need a little imagination to picture pain and suffering. But there is also humour. In a lovely knowing twist, one of the images is a backstage still taken from the movie Conquest of the Planet of the Apes.

“The images in the Last Pictures are primarily inspired by thinking of uncertainty about the future,” explains Paglen, “trying to think through the ways in which humans have produced crises over and over, whether that’s humanitarian crises or ecological crises and thinking about our uncertain relationship with ideas about progress.”

Snapshots of history

Visions of humanity have travelled further in space, of course. The early 1970s Pioneer 10 and 11 missions to Jupiter and Saturn both carried a plaque on the side with a line drawing of a naked man and woman. The man’s hand is raised in greeting and beneath it there is a diagram of the Solar System, illustrating the origin of the spacecraft. The two Voyager probes – both still going strong after 35 years – carry a far more ambitious message from Earth into interstellar space, including audio messages etched into golden records with instructions about how to play them. Any extra-terrestrial being that succeeds in doing so would not only be treated to the sounds of surf, thunder, whale calls and greetings in 55 languages, they would also hear music from Bach, Beethoven, Stravinsky, as well as Johnny B Goode by Chuck Berry.

The Pioneer and Voyager messages were high-minded attempts to communicate with other civilisations, to let them know we are here. Postcards for aliens, if you like. But Paglen says that the Last Pictures project is very different. “[The Voyager team] were very sincere about how to explain life on Earth to extra-terrestrials. This is not like that at all, we’re not going to the final frontier or anything like that.” In fact he does not imagine that his work will find an audience. “I don’t think it will ever be found,” he says.

In that case, why do it? “I really started thinking about how we develop an ethical relationship with the future,” Paglen explains. “Even though we cannot imagine geologic time, or even evolutionary time, or barely think about tomorrow, we can intervene in it. And that’s new.”

“If you look at things like nuclear waste or climate change or geostationary spacecraft, we have set things off into geologic time or cosmic time almost by accident.” In other words, as humans, we have already altered the very far future. The future beyond the lifespan of humanity.

So if we were all wiped out tomorrow, what would we leave behind? We’ve made our mark on Earth, and 20,000 years after our ancestors created bison paintings in caves, we are now leaving snapshots of our memories in space, there for future generations of anyone or anything to stumble upon. Now there are plaques on spacecraft at the edge of the Solar System, expired landers on Mars, spacecraft in orbit around Saturn, Venus and Mercury and even a probe on Saturn’s moon Titan. We have left rovers, flags and footsteps on the Moon, satellites in orbit and now one hundred pictures.

It’s a sobering thought, though, that eventually, even those will be gone – swallowed up when the Sun becomes a red giant in five billion years, or scattered to dust when our galaxy collides with another in four billion; fragmented into nothingness as the Universe expands into infinite darkness. For, ultimately, nothing lasts forever.

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