In mid 1967, PhD student Jocelyn Bell at Cambridge University was helping to build a telescope. She went on to discover a little bit of "scruff" - the first evidence of a pulsar.
Technology is driving a revolution in the way radio astronomers study the universe, and it could lead to new discoveries.
It used to take weeks to find any of these mysterious signals from deep in space but when the new telescope started looking it found one within days. Then another.
Astronomers are making new discoveries about our galaxy thanks to a more detailed map of the Milky Way.
You can't just buy a radio telescope receiver off the shelf. So CSIRO has been hard at work building receivers for the world's largest telescopes using the very latest technology.