A chess set, a university sash, a set of rosary beds, a container of dirt, a model of a Chinese junk are all among objects placed reverentially behind glass in a new exhibition at the National Museum of Australia.

And they may be just objects but they resonate with meaning, with history and experience. The mundane lifted to the exceptional due to their owners, some of Australia's most exemplary citizens.

Each contender for the 2018 Australian of the Year Award selected a meaningful object to put on display in the annual Australian of the Year exhibition.

The joint exhibition with the National Australian Day Council was launched on Thursday by NMA director Dr Mathew Trinca.

"When we ask you to choose a single object, or in some cases a couple of objects, that represent something about your life journey, not only do we learn about you, but we learn about ourselves as well," he said.

That was even in a time when so much of our attention was devoted to the ephemeral, intangible digital world.

"It makes you think about how things still matter and how they might say something...and help us recall aspects of our life journey," Dr Trinca said.

Samuel Johnson, Victoria's 2018 Australian of the Year, chose a small wire unicycle made for him by his sister, Connie, who died in September after devoting her later years to raising funds towards eradicating cancer.

"My sister sent me on the most absurd quest imaginable when she dared me to unicycle around Australia," Johnson's citation reads in the exhibition.

"It was mayhem and it was magic. It happened because Connie demanded more of me. She was a force of nature and always saw a way, no matter how big the dream. That's what I'll miss the most."

The Northern Territory's 2018 Australian of the Year, paediatric cardiologist Dr Bo Remenyi, tellingly chose a painting of a "strong, healthy heart" , the artwork completed from a "patient's grateful mother".

Professor of quantum physics, Michelle Simons, the 2018 Australian of the Year for NSW, chose a chess set and a certificate from the London Primary Schools Chess Association confirming she participated in a chess competition in 1977. The fact few girls participated in the competition might have been confirmed by a mistake on the certificate saying she was selected to play for "his" school.

The chess set was significant, too, because she had been a "silent observer" to games played by her father and brother before she plucked up the courage to challenge her father to a game when she was eight. And she won the game.

"When people don't expect things of you, that makes you want to prove them wrong," she said.

Western Australia's 2018 Australian of the Year, psychologist Dr Tracy Westerman chose a bottle of dirt from the Pilbara region, her homeland, and her mother's 1964 certificate of citizenship, a slip of paper that did not reveal the entrenched racism behind it.

"My mother Mavis Westerman was granted this certificate by attending Port Hedland court in 1964," her citation reads.

"To be eligible, you had to prove you had served ties with your Aboriginal family, were free of disease, could speak English and were 'civilised' in your behaviour."

NRL star Johnathan Thurston, Queensland 's 2018 Australian of the Year, provided signed decorative headgear he had worn in Allstars' games. There was also a heartfelt letter, written neatly in lead pencil, from a fan "Kody" who attends NRL Cowboys House in Townsville, providing assisted accommodation and education opportunities for Aboriginal and Torres Strait Islander students.

Kody wrote in his letter that JT means "Just Terrific" to him.

"I admire the skills that he plays with but I like who he is too. I watch how he is always kind to the ballboys. He pats them on the head to say thank you," the innocent letter reads.

The ACT's 2018 Australian of the Year, entrepreneur and community leader Dion Devow, recognised the importance of faith and education to him. He chose rosary beads and a sash from his graduation ceremony at the University of Canberra, made for him as he was the only graduate that year with both Aboriginal and Torres Strait Islander heritage.

Craniofacial surgeon Professor David David chose three-dimensional models from a patient's CT scans, revealing his approach to life is "all or nothing".

And Tasmania's 2018 Australian of the Year, theatre director Scott Rankin, included a model of a Chinese junk, growing up on such a vessel, that unconventional start to life sending him down a creative path.

"Like me, it gets more decrepit over time, a reminder of that early freedom," he said.

The 2018 Australian of the Year exhibition is at the National Museum of Australia until February 18 before it travels nationally. Entry is free.