About once a century on any given square kilometre of Earth, a cosmic ray hits with mind-boggling intensity. The teeny tiny subatomic particle from space comes careening in with more than 10 million times the energy of particles shot out by the LHC. Where do these ultrahigh energy cosmic rays come from?
Astronomers have a plan to find out, using the moon and a massive new radio telescope array. The £910 million array, which is in development now, is so massive that doesn't fit on one continent. Spread out over thousands of miles across Australia, New Zealand, and South Africa will be thousands of radio telescopes that, together, add up to the Square Kilometre Array. The total collecting area of the array is one million square metres, or one square kilometre, hence its name. When it's completed in 2015, it will be the world's biggest and most sensitive radio telescope.