Hundreds of thousands of members of the public are helping a team of astronomers to discover a group of rare galaxies.
You too can take part in this mass experiment even if you have no previous astronomy background or experience.
The “citizen scientists” help classify galaxies in an online image bank, through a project called Galaxy Zoo. Its finding of rare galaxies called “Green Peas” could give unique insights into how stars were formed in the early universe.
“It’s not just for fun,” says Kevin Schawinski, an astrophysicist at Oxford University.
Kevin is part of the team who devised the mass observation project, and says: “The human brain is actually better than a computer at pattern recognition tasks like this. Whether you spend five minutes, 15 minutes or five hours using the site, your contribution will be invaluable.”
Since the launch of Galaxy Zoo in 2007, over 230,000 volunteers from around the world have taken part.
What’s involved
The Galaxy Zoo website starts by giving you a quick (three- or four-minute) tutorial.
Then they ask you to you classify a short series of images from a telescope in New Mexico.
For example, you decide whether an image of a galaxy is spiral or elliptical. If it’s a spiral, you say which way it appears to be rotating.
As the organisers explain, “If you find it hard to decide upon the answer to a particular question, don’t worry! There often won’t be a ‘correct’ answer. Just pick the one that seems best and move on to the next question.”
Green Pea discovery
The volunteers at Galaxy Zoo came across a number of objects that stuck out because of their small size and bright green colour.
They began discussing this in their online forum, and dubbed the strange new objects “Green Peas” – the original forum thread was called “Give peas a chance”.
They then helped the astronomers to do further analysis, and the Green Peas turned out to be small, compact galaxies that were forming stars at an incredibly high rate.
Of the one million galaxies in Galaxy Zoo’s image bank, the volunteers managed to pin down 250 Green Peas. It’s a task that no one individual could have completed.
The Green Pea findings will be published in an upcoming issue of the Monthly Notices of the Royal Astronomical Society. The scientific paper acknowledges 10 Galaxy Zoo volunteers as having made a particularly significant contribution.
Learn more
Visit Galaxy Zoo and take part in the project
Read how our Science Ambassador Dave McDonald became interested in astronomy – and discovered an asteroid from his back garden in Co Kildare
Find out how you can learn astronomy on your iPhone
