I remember it as if it happened yesterday. I was 19 and on my way to see The Manchurian Candidate with friends when Billy Noonan told us: "Hey, did ye hear that President Kennedy's been shot?" Later, in the Pavilion Cinema in Cork, they flashed a hastily written manuscript upon the screen to tell us that the President had died in Dallas.
Kennedy's death in this respect is something of a cliche, in that everyone remembers exactly where they were when it occurred.
But there are other happenings that are equally vivid in our lives, and in the case of meteorologists above a certain age, a chronological beacon shining from the distant past is one's memory of that first sighting of a picture taken by a weather satellite.
The experience was a revelation, something completely new.
In my case, I recall, two things struck me about those images that we received at Shannon in the summer months of 1967: amazement that the geographers should have got the shape of Europe so exactly right; and surprise that a depression, viewed from space, appears as a spiral in contrast to the series of concentric circles so familiar from the weather chart.
As it happened, weather satellites by then had been around for quite a while. Sputnik, you will recall, showed us in 1957 that it could be done; three years later, and 39 years ago today, the first satellite dedicated entirely to the weather was launched on April 1st, 1960. It was the American TIROS I, the acronym standing for Television and Infra-Red Observations Satellite. It lasted for two years, and transmitted 20,000 pictures down to Earth.
There have been hundreds of weather satellites since. TIROS could only provide a simple picture of the weather systems, but today's spacecraft give us numerical values of temperature, wind and rainfall over the vast areas of their field of view, data that are invaluable as an input to the forecast over large regions of the world where conventional observations are few and far between.
They also allow us to monitor the effects of global warming, and to keep a watchful eye upon the health of the ozone layer.
One might think, of course, that if the meteorologist's "eye in the sky" can see exactly what is happening to the weather all around the globe, there must surely be no excuse for the forecaster ever to be wrong again. But satellites, alas, are not a panacea: they show the weather as it really is, but on the future development of the atmospheric systems, the satellites remain discreetly silent.