An Astrobiology Droid Asks And Answers ‘How Many Ways Can You Say Water’?

I have been living with the image in my mind of the Pioneer plaques and Voyager Golden Records heading across the outer solar system and into interstellar space for half a century. To me, that was the most Carl Sagan – of Carl Sagan – ideas. All these years later – despite its Disco era origins – it transcends time well – which is exactly what you want a message to the inhabitants of another solar system to embody.

Well, NASA just did something as cool – and in some ways even cooler.

Europa Clipper is in the final stages of assembly. It is scheduled for launch in October 2024. In advance of this mission NASA has done a bunch of the usual outreach things – send your name, etc. They also got America’s Poet Laureate to compose a poem to accompany Europa Clipper. That was cool.

But then, in Sagan+ fashion, they cobbled together some plaques – etched in metal that should be impervious to a long stay in space. Europa Clipper is not leaving our solar system. Instead it will circle Jupiter and examine Europa. It will eventually be crashed into Ganymede once its mission is complete.

Since Europa is an icy world with a subsurface ocean, this mission is very much about water – and the possibility that habitable conditions exist within that ocean. And while “habitable” does not mean “inhabited” it does move us a step closer to finding out if life is possible in Europa’s ocean – and how to possible go back and look for it. Astrobiology is in the driver seat on this mission.

According to a NASA press release “Made of the metal tantalum and about 7 by 11 inches (18 by 28 centimeters), the plate features graphic elements on both sides. The outward-facing panel features art that highlights Earth’s connection to Europa. Linguists collected recordings of the word “water” spoken in 103 languages, from families of languages around the world. The audio files were converted into waveforms (visual representations of sound waves) and etched into the plate. The waveforms radiate out from a symbol representing the American Sign Language sign for “water.” To hear audio of the spoken languages and see the sign, go to: go.nasa.gov/MakeWaves.

The art on this side of the plate, which will seal an opening of the vault on NASA’s Europa Clipper, features waveforms that are visual representations of the sound waves formed by the word “water” in 103 languages. At center is a symbol representing the American Sign Language sign for “water.” Credit: NASA/JPL-Caltech

OK is this is cool – and it builds upon the idea of messages from Earth that were placed on the Voyager Golden Record. The Pioneer graphics used symbols to help possible alien readers locate our solar system via distances to pulsars. The Europa Clipper graphics focus on water – and the myriad ways that humans say the word. But it was the inclusion of ASL sign for water that got my attention. How did they do that? I looked closely and all I saw was some kind of science emoji-like thing – if you are old like me you might be reminded of an old TV test pattern.

You see back in another life in my 20s and 30s I worked as a professional Sign Language interpreter. Don’t ask why, I just stumbled into it. It’s my second language – one that I learned barely out of my teens. And I do not pass on opportunities to make sure it is included in things that NASA does. Back in 2012 the Robonaut 2 droid was sent up to the ISS. It started to move its robot hands around and at some point NASA Public Affairs quoted the robot as saying “I have no voice”. Well, that’s not true. It has hands. Flash forward (after some complaints on NASAWatch) and Robonaut started to sign “Hello” based on the suggestion I offered along with my complaints. (see “Robonaut-2 Says “Hello world” in American Sign Language From the ISS“).

So now there is ASL on an astrobiology-themed mission. That is cool. Back in 1977 I first saw the film “Close Encounters of the Third Kind” with my deaf roommates. None of us knew that the aliens were going to sign (video) so we all freaked out when one of them did. Of course, it was natural to us that all aliens would know how to sign – since they all already speak English, right?

Back to Europa Clipper. When I enlarge the part of the plaque with all of the sound patterns I see a little symbol at the center. I may be a little rusty with my ASL, but I am pretty sure that is not ASL. So I asked NASA JPL PAO about this. Preston Dyches, who has the cool title on LinkedIn as “Space Exploration Storyteller at NASA’s Jet Propulsion Laboratory”, called me and explained.

According to Preston the audio sound traces were easy enough to convert into familiar wave graphics and laser etch into metal. But unless you use holography, it’s a little hard to take a three dimensional image that morphs through time and etch it onto anything other than an actual hologram. So they took a simple line graphic (first image) of someone signing “water” and they made a Fourier Transform of this symbol. As you can see in the second image it has a fine gradient which is really not compatible with the laser engraving that they were doing. So they derived a vector graphic from that Fourier transform that follows the same radial pattern – and that is what was etched in the center of all the sound patterns.

Now it all makes sense. It is certainly much more stylish than a QR code.

But wait there’s more. According to the press release:

“Because searching for habitable conditions is central to the mission, the Drake Equation is etched onto the plate as well – on the inward-facing side. Astronomer Frank Drake developed the mathematical formulation in 1961 to estimate the possibility of finding advanced civilizations beyond Earth. The equation has inspired and guided research in astrobiology and related fields ever since. In addition, artwork on the inward-facing side of the plate will include a reference to the radio frequencies considered plausible for interstellar communication, symbolizing how humanity uses this radio band to listen for messages from the cosmos. These particular frequencies match the radio waves emitted in space by the components of water and are known by astronomers as the “water hole.” On the plate, they are depicted as radio emission lines. Finally, the plate includes a portrait of one of the founders of planetary science, Ron Greeley, whose early efforts to develop a Europa mission two decades ago laid the foundation for Europa Clipper.”

This side of a commemorative plate mounted on NASA’s Europa Clipper spacecraft features U.S. Poet Laureate Ada Limón’s handwritten “In Praise of Mystery: A Poem for Europa.” It will be affixed with a silicon microchip stenciled with names submitted by the public. There is also a depiction of the Drake Equation Credit: NASA/JPL-Caltech larger image

A closing thought: Astronaut Tracy Dyson is going back to the ISS. She is fluent in ASL (see: “NASA Astronaut Sends First Signed Message from Orbit“). It would be cool if she could sign “water” in the ISS Cupola while floating over our ocean world (or maybe some polar ice) and mention Europa Clipper and thus mix ISS and Astrobiology and planetary science. Although she may be back on Earth when Europa Clipper is launched in early October she could give an additional send off via ASL in space. Just a thought. She certainly likes to look out the window up there.

11 September 2010 Astronaut Tracy Caldwell Dyson gazes down at our water world