Australian astronomer Ken Freeman has won the 2012 Prime Minister’s Prize for Science, more than 40 years after he revolutionised his field with his research on dark matter.

Professor Freeman, the Duffield Professor of Astronomy at the Australian National University’s Mt Stromlo Observatory, is also famous for his work on galactic archaeology, which aims to unpack how our Universe was built.

“It’s a very exciting thing to win and I certainly wasn’t expecting to happen,” he said of his $300,000 prize.

“It’s exciting for me personally but it’s also the first time astronomy has got one of these and it affirms basic science.”

Professor Freeman helped bring the concept of dark matter — the idea that most of the Universe is made up of stuff that cannot be seen — into the mainstream with a 1970 paper on the topic.

“At the time I was doing this stuff, we thought galaxies were just made out of stars, gas and dust,” he said.

Professor Freeman was the first to calculate that the luminous, visible matter in galaxies is only a small fraction of their overall mass.

“There was a clear mismatch, there was a lot more gravity there than we could account for,” he said.

“I was the first person to say, ‘We have a problem here.’”

Dark matter, while it remains one of the greatest mysteries of space, has now been accepted into mainstream astronomy and is thought to make up as much as 97% of the Milky Way and 84% of the Universe overall.

Professor Freeman’s more recent work, in conjunction with University of Sydney astronomer Joss Bland-Hawthorn, delves into the science of how the Universe was constructed, a field now known as galactic archaeology.

Astronomer and Nobel Prize winner Brian Schmidt said Professor Freeman had done more than any other single Australian astronomer to help advance our understanding of the cosmos.

“While Australia’s achievements in astronomy abound, Ken’s scientific discoveries, his supervision of more than 50 PhD students and his scientific leadership make him stand out from the crowd,“ Professor Schmidt said.

Other winners in the Prime Minister’s Prizes for Science include physicist Eric May from the University of Western Australia, for his work towards making liquid natural gas a cleaner resource, and oncologist Mark Shackleton for his work on breast cancer and melanoma.

Table Cape Primary school science teacher Michael van der Ploeg received the award for excellence in science teaching in primary schools for helping to inspire his students to enrol in science and medicine at university.

Salisbury High School science teacher Anita Trenwith received the award for excellence in science teaching in secondary schools for her hands-on approach to teaching science and developing confidence in special education students.