It’s the day before Remembrance Day, when we look back to remember the sacrifices of our ancestors in the two World Wars and by those in more recent operations overseas in our uncertain world. In the modern world, we know about the role of scientists in total war mainly from the dramatic results of the Manhattan Project. Decades of work towards nuclear power were lost, as all efforts were redirected towards getting the atomic bomb before Germany.  During these global conflicts of the twentieth century, many scientists were thrown at the problems created by modern warfare.

Walter Roberts was the astronomer in charge of the Climax Observatory (later renamed the High Altitude Observatory) in Colorado, 1940-45. He made daily observations of the Sun, using a coronagraph, a solar observing devise that had only been discovered by a Frenchman (Bernard Lyot) nine years before he took over operations at the Colorado observatory. Essentially, the coronagraph filters out the unwanted glare of the Sun so astronomers can view the much fainter edge (corona), to observe solar flares and prominences. Before the invention of the coronagraph, observers would have to wait for a total eclipse of the Sun to be able to do this and even then they would only have a couple minutes of viewing time, if the weather cooperated.

Making use of this new instrument, at the Climax Observatory, Walter Roberts discovered that there was a link between radio interference on Earth and solar activity. The importance of this discovery, during World War II, caused it to be immediately classified and for the rest of the war Roberts reported his daily observations directly to the US Navy. Because of the critical importance of radios to coordinate military operations, his reports on solar activity were transmitted to Allied Command in various theatres to ensure no major operations were launched when they would be disrupted by solar activity, effectively jamming their communications. In the lead up to D-Day, Roberts’ reports were transmitted daily to nervous planners in England, to ensure that one of the largest amphibious landings of the war didn’t become a complete fiasco.

Because of the quality of the work by Walter Roberts, during and after the war, Colorado has become a world headquarters of solar astronomy. Straddling the sciences of astronomy and meteorology, his work pushed the boundaries of our understanding, about the relationship between the Sun and our terrestrial weather.  Walter Roberts spent the last decades of his life applying his scientific knowledge and will against a new threat to humanity: Climate Change.