---
title: "Galaxy Zoo"
chunk: 2/5
source: "https://en.wikipedia.org/wiki/Galaxy_Zoo"
category: "reference"
tags: "science, encyclopedia"
date_saved: "2026-05-05T03:49:12.688307+00:00"
instance: "kb-cron"
---

== Volunteers ==
Galaxy Zoo recruited volunteers to help with the largest galaxy census ever carried out. Opening the project to the general public saved the professional astronomers the task of studying all the galaxies themselves, resulting in classification of a large number of galaxies undertaken in a shorter time than what smaller research teams would be able to do, classifying 900,000 galaxies in months rather than years if done by smaller research teams. Computer programs had been unable to reliably classify galaxies: several groups had attempted to develop image-analysis programs. Kevin Schawinski stated: "The human brain is actually much better than a computer at these pattern recognition tasks." However, volunteers astonished the project's organizers by classifying the entire catalog years ahead of schedule. An online forum was later set up two weeks after the initial start, partially due to a large volume of emails being sent around, to the point that it was troublesome for those receiving them to process and respond to them. This led volunteers to point out anomalies that on closer inspection have turned out to be new astronomical objects such as 'Hanny's Voorwerp' and 'the Green Pea galaxies'. "I'm incredibly impressed by what they've managed to achieve," says University of Oxford astronomer Roger Davies, former president of the Royal Astronomical Society."They've made it possible to do things with a huge survey."
The Galaxy Zoo forum became a hotbed for the discussion of the SDSS images and more general science questions. Its 'global moderator', volunteer communuity manager and UK astronomy enthusiast Alice Sheppard, said of it: "I don't quite know what it is, but Galaxy Zoo does something to people. The contributions, both creative and academic, that people have made to the forum are as stunning as the sight of any spiral, and never fail to move me." Author Michael Nielsen wrote in his book Reinventing Discovery: "But Galaxy Zoo can go beyond computers, because it can also apply human intelligence in the analysis, the kind of intelligence that recognizes that Hanny's Voorwerp or a Pea galaxy is out of the ordinary, and deserves further investigation. Galaxy Zoo is thus a hybrid, able to do deep analyses of large data sets that are impossible in any other way." A community feeling was also created. Roger Davies stated: "The community of Galaxy Zoo gives them the opportunity to participate that they're looking for." This community became known as the 'Zooites'. Aida Berges, a homemaker living in Puerto Rico who has classified hundreds of thousands of galaxies, stated: "Every galaxy has a story to tell. They are beautiful, mysterious, and show how amazing our universe is. It was love at first sight when I started in Galaxy Zoo ... It is a magical place, and it feels like coming home at last." The Galaxy Zoo Forum became a read-only archive in July 2014. After seven years online and over 650,000 posts, it continues to generate science.
As of July 2017, 60 scientific papers have been published as a direct result of Galaxy Zoo and hundreds of thousands of volunteers. In previous studies though, it was found that data produced by volunteers was more likely to contain bias or mistakes. However Chris Lintott says that crowdsourced results are reliable, as proven by the fact that they are being used and published in peer-reviewed science papers. Indeed, other scientists have questioned crowdsourcing and crowdsourced studies. Steven Bamford, a Galaxy Zoo research scientist, stated: "As a professional researcher you take pride in the work that you do. And the idea that anybody off the street could come and do something better sounds threatening but also implausible." David Anderson, the founder of BOINC, stated: [For many sceptical scientists] "There's this idea that they're giving up control somehow, and that their importance would be diminished". The continuing goodwill of citizen scientists is also questioned. Chris Lintott stated: "Rather than letting anyone pitch for volunteers, we'd like to be a place where people can come and expect a certain level of commitment".
A conference was held between 10–12 July 2017 at St. Catherine's College, Oxford, to recognise the tenth anniversary of the start of Galaxy Zoo in July 2007. Co-founder Chris Lintott stated: "What started as a small project has been completely transformed by the enthusiasm and efforts of the volunteers... It has had a real impact on our understanding of galaxy evolution." 125 million galaxy classifications resulting in 60 peer reviewed academic papers from at least 15 different projects have been made since July 2007. Discoveries include: Hanny's Voorwerp, Green pea galaxies and more recently objects known as 'Yellow Balls'. On the conference Twitter feed, #GZ10, it states that 10 of the 60 papers have over 100 citations [within the Astrophysics Data System] in 10 years. Karen Masters, an astrophysicist at Portsmouth University and project scientist for GZ stated: "We're genuinely asking for help with something we cannot do ourselves and the results have made a big contribution to the field." As a result of GZ's success, the citizen science web portal Zooniverse was started, which has since hosted a 100 projects.

== Retired projects ==

=== Galaxy Zoo 1 ===
The original Galaxy Zoo consisted  100,000 galaxies imaged by the Sloan Digital Sky Survey. With so many galaxies, it had been assumed that it would take years for visitors to the site to work through them all, but within 24 hours of launch, the website was receiving almost 70,000 classifications an hour. In the end, more than 50 million classifications were received by the project during its first year, contributed by more than 150,000 people. This was started in July 2007 and retired in 2009.