Today is Percival Lowell‘s birthday, and Google have both changed their logo and created Google Mars. I had a poster of that same relief map on my wall during the Beagle and Rover landings a couple of years ago. There are pins showing the locations of Spirit and Opportunity, too.
Percival Lowell was an interesting guy. After Schiaparelli claimed to have discovered calani – translated into english as ‘canals’ but more accurately ‘channels’ – on the surface of Mars Lowell pushed for them as evidence of intelligent life on the planet, creating detailed maps, and even a globe, of their distribution.
Lowell’s theories were challenged as more powerful telescopes became available. Unfortunately, maps drawn by different astronomers failed to match, and many failed to see the canali at all. No less than the great (but ever so slightly crazy) Alfred Wallace debunked the claims. It was eventually demonstrated that they were an optical illusion.
Lowell spent much of the latter part of his life searching for Planet X, a world he predicted based upon variations from gravitational theory in the orbits of Uranus and Neptune. He never found anything, but Pluto was discovered 14 years after his death.
It’s ironic that both of Lowell’s major interests turned out to have merit, although his reasoning was flawed in both cases. Mars does indeed have a system of water channels, although not created by any intelligent beings and not visible from Earth-based telescopes. Pluto is not in fact Planet X, as the problems with Uranus and Neptune’s orbits were to do with incorrect values for their masses being used in the equations. Pluto is too small to affect the major planets to any detectable extent.
Lowell also did much for the promotion of astronomy, however, and it seems likely that he instigated much study of Mars. Although the idea of water on the planet was very unlikely, some questions remained until probes visited the planet in the 1960s. He is also credited with inspiring the search which lead to the discovery of Pluto, and he founded the Lowell Observatory in Flagstaff, Arizona, which is still in use today.