Big and grey with oily skin. Two dark-coloured eyes. Lipless mouths dripping saliva and surrounded by tentacles. Ghastly invaders from a distant, dying landscape. That’s the fictional vision fuelled by American astronomer Professor Percival Lowell. 107 years ago he observed water on Mars. This week the US’s National Aeronautics and Space Administration announced that the liquid does indeed flow in the summer months on Mars, ending a century of professorial ridicule.

Lowell’s Mars theories, including artificial water canals, were proven false. But his proclamation of Martian water was also derided by the scientific community. He now deserves to be popularly remembered.

Professor Lowell founded the first observatory to be deliberately located in a remote place for optimal viewing. That’s become standard today. He led the search for Planet X which resulted in the discovery from his observatory of Pluto 14 years after his death. Its astronomical symbol is a stylized P-L monogram, Lowell’s initials. Craters on the Moon and Mars have been named after him.

Lowell popularised science more than anyone in his age. H.G. Wells’ novel ‘The War of the Worlds’ extrapolated on his theories. The most famous adaptation is the 1938 radio broadcast narrated by Orson Welles. The first 40 minutes was presented as a news bulletin. American listeners were panicked and outraged. They believed the extra-terrestrial invasion was real. We have Lowell to thank for that as well. But today apart from scientists, few know of him.

After this week’s NASA announcement, think of tentacles. Lowell was right. There is water up there.