The Square Kilometre Array (SKA), a radio telescope to be built at CSIRO's Observatory in Western Australia, will ultimately have a total collecting area of one square kilometre (hence the name) ten times larger than an existing facility. It will be so sensitive it could detect an airport radar on a planet tens of light years away.
This sensitivity will revolutionise our understanding of the Universe and the laws of fundamental physics. Astronomers will be able to track the growth of millions of galaxies through cosmic time, perhaps finally nailing the nature of the mysterious dark energy. And they'll be able to trace the giant magnetic fields that run through the universe, learning what generates them.