SEMAINE 27 – JOUR 3 Reading + Writing + Listening

Scientists investigating a strange radio signal detected by a Chilean observatory last month say the source must be located somewhere in the outer solar system, though they acknowledge its precise origin might not be identified for several years. The signal, which pulses at irregular intervals, could be the result of naturally occurring plasma interactions, or it may indicate the presence of an unknown geological phenomenon on one of Neptune's moons.

Dr Leila Farrokhzad, who leads the research team, explained that, while the signal is unusual, it cannot be extraterrestrial intelligence — the modulation patterns are too simple and too slow. "It must be something physical," she told reporters, "but at this stage we can't be certain what. The data might suggest volcanic activity, or the signal could turn out to be interference from an old space probe."

Astronomers outside the project may well disagree with that conclusion. Professor Tomás Arrieta of the University of Santiago argues that the probe explanation can't be right: no probe should be transmitting from that region. The matter might remain unresolved until the next generation of deep-space telescopes comes online — a development that could still be a decade away.