All articles
Every article in Signals published in 2026, newest first.
-
The Wow! Signal, Six Characters and a Note in Red Ink
The Wow! signal is a 72-second radio burst recorded by Ohio State University's Big Ear telescope on 15 August 1977 and found days later on a computer printout by Jerry Ehman, who wrote "Wow!" beside it. It showed every mark the search looked for in a beacon, and never came back. Here are the printout, the searches, the explanations offered since, and what is still open.
-
Tesla's Colorado Springs Receiver and a Signal That Counted
In 1899 Nikola Tesla ran an experimental station at Colorado Springs, where his receivers picked up electrical disturbances he could not trace to the Sun, the aurora or the Earth. He told the Red Cross and Collier's Weekly that he might have heard one planet greeting another. Here are his own words, the station, the explanations proposed since, among them Marconi and Jupiter, and what is still unsettled.
-
The Chilbolton Formation and a Reply to the 1974 Arecibo Message
In August 2001 a rectangle of flattened wheat appeared in a field beside the Chilbolton Observatory radio dish in Hampshire. The researcher Paul Vigay read it as the 1974 Arecibo message sent back with changes: silicon added, a different figure, a different transmitter. This is the record of that field, the case for a reply, the case for human makers, and what is still open.
-
The Eindhoven Echoes and the Seconds Nobody Could Place
Long delayed echoes are radio signals that return seconds after they were sent, far later than any path around the Earth allows. They were first reported in 1927 by Jorgen Hals in Norway, from the Dutch station PCJJ, and timed in 1928 by Carl Stormer and Balthasar van der Pol. In 1973 Duncan Lunan read them as a message from a probe. Here are the records, the readings and what is still unexplained.