Back at the beginning of Galaxy Zoo some of our vigilant volunteers started spotting a type of galaxy that appeared unusual. They are small, round and greenish-blue. Their colour is due to an unusually high rate of star formation. It turned out that they were an entirely new class of galaxy! Their discovery is a great example of the power of citizen science. You can read the scientific paper of their discovery here.
Have a look for some green peas at www.galaxyzoo.org