Millions of people in Mexico, the US and Canada experienced a total solar eclipse on Monday. The spectacle occurs when the moon passes between the sun and the earth, completely obscuring the sun and leaving only a bright ring of fire visible. Beginning over the Pacific Ocean, the core shadow stretched across northern Mexico, crossed the US from Texas north-eastwards to Maine, grazed south-east Canada and ended over the North Atlantic. In Mexico, thousands of tourists and residents in the coastal town of Mazatlán on the Pacific Ocean watched as the solar eclipse darkened the day for a few minut…