The Google Science Fair is an annual contest that runs from February to May, open to anyone ages 13-18. The site displays winning entries from previous years, which are interesting to read about. The broad topics are

● Flora & Fauna
● Food Science
● Earth & Environmental Sciences
● Inventions & Innovation
● Electricity & Electronics
● Robotics
● Biology
● Chemistry
● Physics
● Behavioral & Social Sciences
● Energy & Space
● Astrophysics
● Computer Science
● Math

There is a springboard that suggests topics to work on based on a student's interests and aptitudes. The rules are here.

Thanks for sharing this. I played with the idea springboard, entering various answers, and found an awesome array of different resources was presented each time. Beyond providing possible inspiration for the google science fair, the idea springboard could be a great way to gather new resources to study on a rainy day or for any occasion.