July 26, 2021

I, Science

The science magazine of Imperial College

When Giovanni Schiaparelli tilted his telescope towards Mars in 1877, he was hardly expecting to answer one of humanity’s enduring questions: are we alone in the Universe? Yet, what he found sparked almost a century of heated debate about whether he had done just that.

The Italian observed a series of long, straight lines, or ‘canalis’, carved into the rocky surface of our celestial neighbour. Astronomers, most notably Percival Lowell, cited these as direct proof of an advanced civilization — canals that carried water from the planet’s icy poles to the arid equatorial regions. It didn’t seem to matter that Schiaparelli never made any mention of aliens (canalis actually means channels — a subtle but important mistranslation); the idea of life in our cosmic back garden was too appealing to ignore, and the Martian myth was born.

Despite being embraced by popular culture, scientists greeted the findings with scepticism. Some astronomers accepted that ‘canals’ existed, but preferred geological explanations over the presence of little green men. Others dismissed them as illusions, caused by the inadequacies of their equipment. Viewing Mars pushed telescopes to their resolution limits, meaning that separate points, such as craters, could easily be confused as one. Enough of these points along a straight path might suggest one solid line. It was not until NASA sent a series of probes to the red planet in the 1960s and 70s, which failed to find any evidence of canals or channels, that the issue was finally put to rest.

Despite its absurdity, the whole saga gives an insight into the power of belief in shaping observation. The 19th century was a time of frantic industrialisation, supported in part by the construction of a network of canals. It is no coincidence that astronomers searching for the signs of intelligent life saw products of their own civilization though their lenses. They wanted to believe so badly that they saw exactly that which would support their views.

Whilst many people were disappointed by the lack of life on Mars, it might turn out to be a blessing. After all, as Stephen Hawking remarks, if intelligent life is anything like us, do we really want to meet them?

By Jan Piotrowski