50 years ago

'Whistlers' are being heard consistently at Scott Base, the New Zealand International Geophysical Year Antarctic Station, McMurdo Sound. From the time observations commenced on April 15 until the time of writing considerable activity has been observed, including 'bonks', 'tweeks', short and long 'whistlers', whistler trains, and periods of strong 'sferics'. No dawn chorus has yet been observed... It is believed that this is the first time that whistlers have been heard in such a high geomagnetic latitude. The whistlers appear to have dispersion characteristics similar to those heard in lower geomagnetic latitudes. However, the characteristics cannot be truly determined until tape recordings of them are sent to New Zealand for spectrographic analysis, at the end of the Antarctic winter.

From Nature 28 June 1958.

100 years ago

“The rings of Saturn” — In a note published as Bulletin No. 32 of the Lowell Observatory, Prof. Lowell develops rather more fully the idea that the appendages B and C of Saturn are not flat rings, but tores. He arrives at this conclusion, by two independent methods, from a discussion of the phenomena observed at Arizona during November and December last. In the first place, a black core was observed running medially through the length of the shadowy band which then encircled the planet. This core...is presumed to be the black shadow of the plane ring A bordered by the particles of the rings B and C scattered above and below the plane of A. That is to say, the rings B and C differ from A in being tores and not flat rings... The assumed heaping up of the particles, as indicated by the agglomerations [seen at many observatories], is in accordance with gravitational laws. Furthermore, it is shown from the observational results that the inevitable disintegration of the rings is in the process of taking place.

From Nature 25 June 1908.