When most people think of humanity's attempts to contact alien intelligence, they think of the Arecibo Message or the Golden Record. Fewer know about the Evpatoria transmissions — a series of broadcasts from Ukraine that, for sheer ambition and technical complexity, rank among the most sophisticated messages ever sent beyond Earth.
From 1999 to 2008, scientists using the Evpatoria Planetary Radar facility in Crimea launched "Cosmic Call" and "Teen Age Message" toward Sun-like stars within 50 light-years of Earth. These weren't simple binary pulses or mathematical diagrams. They were digital encyclopedias. They were music. They were paintings. They were video. And they were encoded using the state-of-the-art compression algorithms available at the turn of the millennium.
The Cosmic Call
The first transmission, "Cosmic Call," launched on May 24, 1999, aimed at four potentially habitable exoplanets (though calling them that seems quaint now — we didn't even know they existed until 1992). The message contained:
- Fundamental mathematics and physics: sequences of prime numbers, basic arithmetic, the periodic table of elements
- Photographs: 100 images from Earth, including paintings, scientific diagrams, photographs of Earth's landmarks and people
- Text messages: greetings from world leaders and scientists, including messages from Carl Sagan (recorded in 1992, before his death), Stephen Hawking, and other luminaries
- Music: classical pieces, folk music, and experimental electronic music
- Video sequences: brief clips showing human activity
The second "Cosmic Call" transmission on September 4, 1999, went deeper: it included a complete encyclopedia of human knowledge, compressed into the digital message. Over 10 gigabits of information, packed into a signal directed at star systems known to host planets — Epsilon Eridani, Tau Ceti, and others.
The technical achievement was staggering. The Evpatoria facility has a 70-meter diameter antenna — smaller than Arecibo, but still among the largest radar telescopes in the world. They were operating at frequencies originally designed for planetary radar mapping, pushing the limits of what could be transmitted across interstellar distances with the available power.
Teen Age Message
In 2001, the project evolved into something even more ambitious: the "Teen Age Message." The name itself was a statement of purpose. The message was compiled by a group of schoolchildren and young adults from around the world, who were asked: "What would you send to alien intelligence?"
The result was both poignant and chaotic, which is to say it was deeply human. There were messages of hope ("Hello. We come in peace"), technical drawings, musical performances, poetry, and photographs. The idea was that alien intelligence, observing humanity, should see not just our official representatives but our future — our children — speaking directly.
The Teen Age Message was launched multiple times in 2001–2003, aimed at Gliese 581 (then unknown to have planets; we've since found a potentially habitable one there) and other nearby star systems.
The Technical Challenge
Encoding an encyclopedia into a radio signal requires compression, error correction, and a fundamental decision about format. The Evpatoria team used techniques including:
- Lossless compression: PNG image encoding for photographs (which can be decompressed perfectly without loss)
- Video encoding: Heavily compressed video sequences using available standards
- Text encoding: UTF-8 character encoding, allowing the messages to be written in any human language
- Metadata: Detailed headers explaining the signal structure, so a receiver could understand the encoding scheme
All of this assumes something crucial: that an alien receiver will have the computational power and sophistication to decompress and interpret 21st-century digital formats. This is not a trivial assumption. It assumes that intelligence at the receiving end has computers similar to ours, or at least similar enough to handle the algorithms.
The Reception Problem
Here's the catch: Evpatoria's transmissions were aimed at exoplanets detected through the radial velocity method — meaning the telescopes that found those planets were highly sensitive to their gravitational effects. But the signal transmitted from Earth was not aimed with perfect precision. At the distance of Tau Ceti (12 light-years away), Earth's transmissions would spread out to a beam about 2 light-days in diameter. Miss the target star by a few degrees, and the signal is lost in the background noise of the galaxy.
Moreover, even if the signal reached the target star system, the planet might not be in position to receive it. Planets orbit at specific locations in their orbits. The signal might arrive when the planet is on the far side of its star, shielded by the stellar radiation itself.
The Evpatoria transmissions represent a kind of cosmic gambling: betting that the right message, sent at the right time, to the right place, might be received and understood by intelligence on the other end.
Why It Mattered
The Evpatoria transmissions are less famous than the Arecibo Message or the Golden Record, but they represent a crucial step in the evolution of human-to-alien communication: they were the first to treat the message as a true information system, using the best compression and encoding techniques available. They were the first to think seriously about what an encyclopedia of human knowledge might look like, and how to transmit it.
They also represent a transition point. After 2008, most intentional SETI transmissions stopped, largely because the scientific community (and especially the International Academy of Astronautics) grew cautious about METI without broader consensus and agreement. But the Evpatoria transmissions blazed a path: if we were going to speak to the stars, we could speak in detail. We could share not just our physics, but our culture, our art, our music, and our voices.
The Cosmic Bet
The last Cosmic Call transmission was launched in 2001. The Teen Age Message most recently transmissions in 2003. Since then, no new large-scale intentional transmissions have been launched, though proposals continue to circulate.
What happened to those messages? They are still traveling outward, attenuating as they spread through space, carrying with them the hopes of a Ukrainian space program and the voices of Earth's young people. They will arrive — if anywhere — around 2012 at the nearest targets. But they will arrive to planets orbiting stars that have no way of knowing we sent them. The message will be indistinguishable from background cosmic noise, unless there happens to be a radio telescope there, pointed at exactly the right place, listening at exactly the right frequency, at exactly the right time.
The odds are vanishingly small. And yet we sent it anyway. That is the story of the Evpatoria transmissions: humanity, using its finest technical achievements, betting on the possibility of contact. Betting that the universe cares enough to listen.