Our Cosmic Ancestors by Maurice Chatelain

seventh of one second.
    On the contrary, abnormal echoes always came back after an interval varying from 3 to 15 seconds, as if they had bounced from some object located at a distance from Earth of 450,000 to 2,250,000 km, but always a little bit farther than the Moon. As usual, this discovery was kept as secret as possible, and, after several years, it was even completely forgotten.
    Then a few years ago, a young Scottish astronomer by the name of Duncan Lunan had a bright idea. He thought that these signals could very well have come from an alien spaceship orbiting the Earth at about the same distance as the Moon and that the variable intervals between the transmission of signals and reception of echoes might represent an intelligent coded message representing geometric figures or even the map of a constellation, as Bracewell had already suggested in 1968.
    With the usual television technique of so many dots per line and so many lines per frame, Lunan transferred the various intervals on a chart as he would have done on a television screen. He then successively obtained several different drawings of the same constellation, with different orientations, but with the same star always at the centre.
    As Lunan says in his book Man and the Stars, as an astronomer it did not take him long to recognize the constellation as that of Bootes and the star as Epsilon Bootis, which our ancestors called lzar and which is located at about 103 light-years, or 975 million million km, from the Earth.
    One of Lunan's important discoveries was that the configuration of the Bootes constellation shown on his charts was not exactly the same as that which we can see today from the Earth, and he found an explanation. The big star Alpha Bootis, or Arcturus, is one of the fastest moving stars in our skies. It has an angular motion of 2.29 seconds of arc per year in a southwest direction, and its position in the sky moves by an apparent diameter of the Moon in only 800 years.
    According to Lunen, Arcturus now appears to us about seven degrees apart from where it appears on the chart, which means that the map could have been established and transmitted 11,000 years ago. However, Arcturus does not move with a constant apparent velocity, and taking an average of only 2 seconds of arc per year, we obtain a date of 12,600 years ago which corresponds to those of the other stars of the same constellation.
    As a consequence, assuming there is an alien spacecraft presently orbiting the Earth, it arrived in its present position about 13,000 years ago; and, after observing the configuration of their native constellation of Bootes as they saw it from their orbit around the Earth at that time, the astronauts on board have been continuously transmitting signals since then, waiting for human astronomers to become intelligent enough to understand them.
    Finally, around 1900, the first radio signals were transmitted from the Earth by Marconi, Tesla, and others, and the Izarian astronauts knew they were now in business. They started retransmitting the earth signals, with various intervals representing a code, and the code represented a map of the constellation of Bootes with the star lzar at the centre.
    For me, however, the most extraordinary and the most controversial part of the story is not so much the constellation map as the intervals between the different signals from the alien spacecraft. These intervals are always an exact number of seconds of time and, as you know, our second of time is supposed to be a human invention. Up to now, the Sumerians have been credited with the fantastic idea of dividing the solar day into 86,400 equal parts they called seconds.
    In other words, these alien astronauts from a distant planet in outer space, who had been orbiting our planet in a spacecraft for 13,000 years, knew from the very beginning that the human race divided the solar day into 86,400 seconds of time. And how could they know it
unless they made the division