One night a few years back I had a late night call from a friend who was involved in Breakthrough Starshot, the attempt to design a probe that could reach nearby stars and return data with transit times of decades rather than centuries. His news was surprising. The Parkes radio dish in Australia, then being used by the Breakthrough Listen SETI project, had detected a signal that seemed to come from Proxima Centauri. “What’s interesting,” said he, “is that when you move the dish off Proxima, the signal disappears.” You probably remember this episode, which had a brief moment in the news and may well live on among the conspiracy-minded in the wackier regions of cyberspace. We know now that the signal was some form of radio frequency interference, commonly abbreviated RFI. In any case, our conversation was relatively tame because the idea of a terrestrial explanation seemed inevitable, no matter how tantalizing the first look at this signal. After all, with all the years of SETI effort...

"We were dreamers, dreaming greatly, in the man-stifled town; We yearned beyond the sky-line where the strange roads go down. Came the Whisper, came the Vision, came the Power with the Need…" -- Kipling, from "The Song of the Dead" We’re lucky that science fiction fans are such packrats. They not only keep beloved books and magazine issues from their past but also catalog them relentlessly. Because of both these traits, I can turn to my own bookshelf and pull out the November, 1957 issue of Astounding Science Fiction to see P. Schuyler Miller’s review of John Campbell’s Islands of Space, in which he described the novel as “very characteristic of the best ‘hard’ science fiction of its day.” Miller had a lot to do in subsequent book reviews for the magazine with establishing ‘hard SF’ as a category. Campbell’s book, extensively revised from its original appearance in the spring, 1931 issue of Amazing Stories Quarterly, is an interesting curiosity in being the first appearance of a...

Transients have always been intriguing because whether at optical, radio or other wavelengths, they usually flag an object worth watching. Consider a supernova, or a Fast Radio Burst. But non-repeating transients can have astronomers both professional and amateur tearing their hair out. What was Henry Cordova, for instance, seeing in the Florida sky back in 1999? The date seems significant, as we were moving toward the Y2K event, and despite preparation, there was some concern about its effects in computer coding. Henry, a retired map maker and geographer as well as a dedicated astronomer, had a transient that did repeat, but only for a short time, and one that may well have been entangled in geopolitical events of the time. I’m reminded of our reliance on electronics, and the fact that some 60,000 commercial flights have encountered bogus GPS signals, according to The New York Times (strikingly, the U.S. has no civilian backup system for GPS). What goes on in orbit may keep us...

Studying the rich history of interstellar concepts, I realized that I knew almost nothing about a figure who is always cited in the early days of beamed sail papers. Whereas Robert Forward is considered the source of so many sail concepts, the earliest follow-up to his 1962 paper on beamed sails for interstellar purposes is by one G. Marx. The paper is “Interstellar Vehicle Propelled by Terrestrial Laser Beam,” which ran in Nature on July 2, 1966. Who is this G. Marx? My ever reliable sources quickly came through when I asked if any of them had known the man. None had, though all were familiar with the paper, but Al Jackson sent me a copy of it along with another by J. L. Redding (Bishop’s University, Canada), who published a correction to the Nature paper on February 11, 1967. It didn’t reduce my confusion that Redding’s short contribution bears the exact same title as Marx’s. My other contacts on Marx had no personal experience with him either but were curious to learn more. Image:...