Overlap Zoo

Galaxies, which are themselves vast collections of billions of stars, gas, and dust held together by gravity, are scattered across the immensity of space. Every so often, a rare cosmic coincidence occurs: two galaxies overlap one another in the sky, lining up perfectly from our point of view (on Earth or from a telescope in space). These rare overlapping galaxies let us study something normally invisible: the dust in the foreground galaxy.

As a volunteer in Overlap Zoo, you’ll view images that volunteers in a different project (Galaxy Zoo) previously identified as containing overlapping galaxies. The Overlap Zoo project will teach you how to verify the presence of galaxy pairs in these images, classify key features of each galaxy, and mark their outlines. Your work will help build the first large-scale catalog of galaxy pairs suitable for dust studies and enable a huge step forward in accuracy of astronomical estimates.

What you’ll do:

• Learn how to recognize two types of galaxies, smooth and featured, in galaxy pairs.
• Examine images of galaxies and answer questions about the kinds of galaxies you see and their orientation in space by clicking buttons and drawing their outlines.
• If you like, you can discuss what you find with other volunteers and scientists in an online Overlap Zoo Talk forum (https://www.zooniverse.org/projects/tbutrum/overlap-zoo/talk).

The Overlap Zoo project’s Research page (https://www.zooniverse.org/projects/tbutrum/overlap-zoo/about/research) gives an overview of the value of overlapping galaxies to astronomy, especially to scientists interested in learning more about cosmic dust and its impact on observational astronomical data. The Frequently Asked Questions (FAQs) page (https://www.zooniverse.org/projects/tbutrum/overlap-zoo/about/faq) has additional, practical information relevant to doing the work of the project.