Billions upon billions, Galaxy Zoo

It’s been a while since I first mentioned the super amateur astronomy project Galaxy Zoo where members of the public get to classify galaxies and so help astronomers build a better view of the universe. September 2009 on SciScoop, in fact.

Roughly one hundred billion galaxies are scattered throughout our observable Universe, each a glorious system that might contain billions of stars. Many are remarkably beautiful, and the aim of Galaxy Zoo is to study them, assisting astronomers in attempting to understand how the galaxies we see around us formed, and what their stories can tell us about the past, present and future of our Universe as a whole.

The idea is based on the fact that you we tell an awful lot about a galaxy just from its shape. If you can spot a system with spiral arms, for example, then most of the time you’ll know that you’re looking at a rotating disk of stars, dust and gas with plenty of fuel for making new stars. Find one of the big balls of stars known as ellipticals, and you’ll most likely be looking at an old galaxy, one that no longer makes new stars.

The history of a galaxy is revealed by its shape. Ellipticals are usually formed by head-on collisions between two smaller galaxies, warped disks, large bulges or long streams of stars are testament to the complexity of galactic evolution.

Visit the site now and start classifying and you will see pictures of astronomical objects from the database of The Sloan Digital Sky Survey (SDSS) which started in 2000 and used a 126 megapixel imaging camera and two fibre-fed spectrographs, mounted on the dedicated 2.5 metre telescope at Apache Point Observatory in New Mexico to create a vast map of the night sky.