Dr Kavan Ratnatunga studied at Royal College, Colombo. He got a First Class BSc Honours Degree in Physics in 1976 from the University of Ceylon, Colombo. He qualified as an astrophysicist, with a 1979 MS from University of Pittsburgh in USA, and a 1983 PhD from Australian National University, specializing in automated statistical analysis of astronomical data and digital images. His 25 year career included research at Institute of Advanced Study in Princeton (1984/86), Dominion Astrophysical Observatory in Victoria Canada (1986/88), NASA Goddard Space Flight Center in Greenbelt (1989/91), Space Telescope Science Institute and Johns Hopkins University in Baltimore (1992/96), and Carnegie Mellon University in Pittsburgh (1996/2004). Highlights of over 50 publications in refereed Journals included the First in-situ sample of Field Halo K-giants in Galactic Halo (1983), and the First Quad Gravitational Lens discovered with NASA Hubble Space Telescope (1995).
He retired back to Lanka in 2005. His current interest include increasing the information on Lanka on the Internet via his domain lakdiva.org Archaeology with a special interest in Numismatics (coins.lakdiva.org), and rare books on Lanka (books.lakdiva.org). At the Post Graduate Institute of Archaeology in 2010 he did a Diploma in Museology and from 2013 doing research for a PhD in Archaeology.
He is vice President of the Sri Lanka Numismatic Society, and the Archaeological Society of Sri Lanka. He is ex-co member of the Internet Society of Sri Lanka, and the Royal Asiatic Society of Sri Lanka He is a Trustee of the National Trust of Sri Lanka He is a life member of the Sri Lanka Rationalist Association, the Sri Lanka Philatelic Society, and the Sri Lanka Association for the Advancement of Science of which he was the Chairmen, Commitee for the Popularization of Science in 2007. He is President of the Sri Lanka Astronomical Association He is member of the International Astronomical Union (IAU), on behalf of which he was the chairman of the International Year of Astronomy IYA2009 committee for Sri Lanka.
He writes Free lance to the Sunday Times of Sri Lanka. He is a visiting Lecturer on Astronomy (DE1412) at the University of Moratuwa at Katubedda, and on Digital Collections at the Post Graduate Institute of Archaeology (PGIAr) of the University of Kalaniya. He gives Guest Lectures on Astronomy, Numismatics, and the Internet on invitation.