Help astronomers explore the Universe!

Help astronomers explore the Universe!


Help astronomers explore the Universe!

Galaxy Zoo is an online astronomy project in which volunteers  assist in the classification of over a million galaxies, according to their shapes — a task at which the human brain is better than even the fastest computer. 

More than 1,50,000 people have volunteered  so far, and their participation has produced  a wealth of valuable data.  Over the past year, volunteers from the original Galaxy Zoo project — ordinary people like you and me — have created the world’s largest database of galaxy shapes.

This database is already revealing  surprising facts about the nature of galaxies. For example, astronomers’ assumption that if a galaxy appears red in colour, then it is also probably an elliptical galaxy has gone for a toss. Thanks to the volunteers’ help, Galaxy Zoo has shown that up to a third of red galaxies are actually spirals. Similarly, there is a much larger number of blue ellipticals than previously thought, and this revelation is largely due to the volunteers’ enthusiastic participation in the project. It is not knowledge of astronomy but willingness on the part of the volunteer that is required for participation in the project. Potential volunteers are shown spirals, ellipticals and so on, and asked to guess before the correct answer is provided to them.  They are also shown unclassified pictures of stars and satellite trails recorded by robot telescopes.

When shown an image of a galaxy the potential volunteer is asked a series of questions about it. All he/ she needs to do is to look for features that mark out different types of galaxies and answer the questions to the best of their ability. As this is a job that humans are much better at than computers, most of the questions are fairly easy to answer.

If the answer to a particular question isn’t easy, don’t worry as often there won’t be a correct answer.  Just pick the one that seems best and move on to the next question. The volunteer’s individual response for each galaxy is extremely important as Galaxy Zoo scientists sift through the responses and work out which is most likely to be the right answer.

How the site was born

The original Galaxy Zoo was launched in July 2007, with a data set made up of a million galaxies imaged with the robotic telescope of the Sloan Digital Sky Survey. With so many galaxies, the team thought that it would take at least two years for visitors to the site to work through them all.

But within 24 hours of launch, the site was receiving 70,000 classifications an hour. More than 50 million classifications were received by the project during its first year, from people all over the world.

The Astronomy Project Galaxy Zoo is truly a great example of how people can contribute their mite to scientific research.  Many projects are now underway using the data garnered from ordinary folk. Eleven scientific papers based on the overall data classifications are now complete and five have been published, with more to follow.
Galaxy Zoo discoveries such as Hanny’s Object, spotted by a member called Hanny van Arkel, have been instrumental in getting time on professional telescopes. These include Isaac Newton and William Herschel telescopes on the island of La Palma in the Canaries, Gemini South in Chile, WIYN telescope on Kitt Peak in Arizona, IRAM radio telescope in Spain’s Sierra Nevada, Swift and GALEX satellites, and Hubble space telescope.
An improved version called Galaxy Zoo 2, launched last year, focuses on the nearest, brightest and most beautiful galaxies.

According to Kevin Schawinski, a member of the team behind the project, “The human brain is actually much better than a computer at these pattern-recognition tasks.”
Without human volunteers, it would take researchers years to process the photographs, but it is estimated that with as few as 10,000- 20,000 people making time to classify the galaxies, the process could be complete in one month.
To know more on Galaxy Zoo you could browse either its home page at or the Wikipedia page on Galaxy Zoo at

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