Our home is Epsilon Boötis, which is a double star. We live on the sixth planet of seven—check that, the sixth of seven—counting outwards from the sun, which is the larger of the two stars. Our sixth planet has one moon. Our fourth planet has three. Our first and third planet each have one. Our probe is in the orbit of your moon.
The words sound as if they come from a Star Trek script. In fact, says a serious young Scottish science writer and part-time astronomer named Duncan A. Lunan, they may well be true. Writing in Spaceflight, a publication of the British Interplanetary Society, Lunan, 27, says that the words are his translation of a message that may have been relayed to earth by a robot spacecraft from a highly advanced civilization far beyond the solar system. More astonishing, Lunan adds, the automatic vehicle may have been circling the moon for thousands of years, waiting patiently for earthlings to acquire the necessary know-how to contact it.
Lunan, whose article was the topic of a special meeting of the British Interplanetary Society in London last week, has reached back to the early days of radio for support for his contention. In the late 1920s, the Norwegian geophysicist Carl Stormer and a Dutch collaborator, Balthasar van der Pol, sent each other a number of short-wave radio messages. The purpose of the tests was to study a curious side effect. At times the radio signals were followed by mysterious echoes that were picked up as many as 15 seconds after the original transmissions. Indeed, the delays were so long that they could not be readily attributed to atmospheric quirks, magnetic storms or other natural phenomena. To this day, scientists have been unable to solve the mystery of the echoes.
In 1960 Radio Astronomer Ronald Bracewell of Stanford University offered a tantalizing hint. Speculating about the possibility of life elsewhere in the galaxy, he wrote in Nature that an advanced civilization might not necessarily use long-range radio signals to communicate with other intelligent beings. Such signals would be considerably weakened over interstellar distances. Instead, Bracewell said, those far-off beings might employ robot space probes as their message bearers. Sent to a promising nearby star, such a vehicle could swing into an orbit around it at approximately the right distance to encounter a planet with life-supporting temperatures. If it picked up telltale radio signals, the probe might then bounce them back to advertise its presence, thereby producing an effect like the echoes of the 1920s. Finally, as its first message, the robot might transmit a picture of the area of the heavens from which it came.