Harney is well known as an advocate and ambassador for
Aboriginal Australians, and has made several international tours promoting knowledge of Aboriginal Australians. He also appears regularly on TV, radio, and film, often speaking on the subject of
Aboriginal astronomy. In 2003 he published, with Hugh Cairns,
Dark Sparklers, detailing the astronomy embedded in the Wardaman culture. He has been a finalist several times in the
National Aboriginal & Torres Strait Islander Art Award. In August 2009 he featured in a two-man
The First Astronomers show with astrophysicist
Ray Norris at the Darwin Festival, episode on Aboriginal astronomy produced by ABC TV. In 2020, the International Astronomical Union's Working Group for Small Body Nomenclature formally approved the asteroid
1979 MR2 as
7630 Yidumduma in honour of his sharing and promotion of traditional Wardaman astronomical knowledge through film, television, and books, including
Dark Sparkers and
Four Circles. Harney was appointed a
Member of the Order of Australia in the
2026 Australia Day Honours. ==Selected bibliography==