Thousands of students and others are expected to visit the RDS in Dublin over the next few days to view displays at this year's BT Young Scientist and Technology Exhibition.
More than 550 projects from schools, both North and South, have gone on show after the event was formally opened by President Michael D Higgins this afternoon.
The range of topics students have focussed on is wide and gives an insight into the questions that most concern them, with climate change and pollution featuring strongly.
This year sees a significant number of projects focusing on the presence of micro-plastics in our food and our waters.
Other topics examine aspects of sport, online gaming, schooling, gender issues, and even Brexit.
The exhibition is open to the public from Thursday until Saturday, and an estimated 50,000 visitors are expected.
In this, the 55th year of the competition, 55% of the projects have been completed by girls.
Organisers say there has been a particularly strong increase in the number of girls qualifying to participate in the Chemistry, Physics and Mathematics category.
The winner, or winners, will be announced at a special awards ceremony on Friday evening.
The top prize includes a cheque for €7,500, and the chance to represent Ireland at the 31st European Union Contest for Young Scientists in Bulgaria in September.
A science fair for primary school pupils will take place alongside the exhibition.
The Primary Science Fair, now in its 17th year, will bring hundreds of primary students from across Ireland to the RDS from Thursday to showcase their projects.
This year's exhibition comprises four categories: Technology; Biological and Ecological; Social and Behavioural Sciences; and Chemical, Physical and Mathematical Sciences.