In 1962 Harry Messel launched the first Science School for high school students from Australia and New Zealand. There had been previous Science Schools for high school teachers, but Harry wanted to recognise and reward talented senior high school students, and to encourage them to pursue careers in science.

In the late 1960s the Science Schools became international with students from the UK, Japan, and the United States of America. More recently, they have been broadened further with students from Malaysia, Singapore, Thailand and China.

Over the years, more than 3500 young scholars from around the world have gathered in Sydney to be stimulated, inspired and challenged by outstanding lecturers on topics as diverse as Space Science, Time, Nuclear Energy, The Brain, Our Earth, Solar Energy, Biology, Population, Carbon, and The Environment.

To honour the man who had the vision to establish these Schools, from 1999 the Science Schools have been called the Professor Harry Messel International Science Schools.

Alumni of the International Science Schools can be found in senior positions in all walks of life with many of them acknowledging that "their" Science School was responsible for changing their lives and recalling its two weeks as an exciting developmental experience.