Pattern recognition of galaxies

It is likely that you and I (and the other few people who read this blog) are the only humans to have laid eyes on these galaxies.

The Sloan Digital Sky Survey has taken a digital photos of one million galaxies. If you head over to galaxyzoo.org you will be able to learn how to classify galaxies, take a short quiz and then begin sorting out galaxies that most likely have never been seen before. By sorting these images into “spiral galaxies” (like our own Milky Way) or “elliptical galaxies”, visitors will help astronomers to understand the structure of the universe.

This is a Spiral Galaxy is in the Anti-clockwise direction.

It turns out that the human brain is far better than a computer at recognising the patterns that divide ellipticals from spirals. This is why many websites make you use Captcha to prove that you are a human rather than a computer program.

They want us to put this kind into the Edge On Spiral category. Astronomers have spent many decades trying to measure basic galaxy properties such as age, mass or dustiness that may give us some clues as to how they formed and evolved and what precisely the connection between spiral and elliptical galaxies is. However, most studies of galaxies so far have only looked at a few dozen or hundred galaxies in the nearby universe and many aspects of galaxy formation and evolution are still a mystery.

Are these Merging Galaxies? In theoretical simulations astronomers have found that the merger of spirals can create an elliptical, and that an elliptical can become a spiral by accretion of further stars and gas during its lifetime. Pictures of real galaxies in the sky taken with the most modern telescopes on earth and space reveal that such processes are indeed happening in nature. But how frequent are mergers? Are they really important? Does every galaxy go through such fundamental transformations during its lifetime?