Couldn’t agree more, one puzzle solved. Go science!
But I’m curious: If comets typically emit large clouds of hydrogen - why don’t we have more false positives? The HI line is one (if not the most) used frequency in astronomy (and SETI).
eta: from TFA
James Bauer of the Jet Propulsion Laboratory in Pasadena, California, agrees that the hydrogen from comets can extend quite far, but still thinks the signal won’t be strong enough. “If comets were radio-bright at 21 centimetres, I would be puzzled as to why they aren’t observed more often at those wavelengths,” he says.
