Please look at the FAQ and tutorials below to see if your question has an answer. Much of what you need to know is already available:


For help on the SkyServer or CASJobs, or to know more about SQL, consult the SkyServer DR12 Help.

Accessing Data

If you want a list of tools for accessing the data, consult the data access documentation.

About the Data

If you have questions about the nature of the data (what is a plate? what is a run?) consult the spectroscopic and imaging documentation pages.

Data Analysis

If you have a question about a technique used in the data analysis, see if it is addressed in the algorithms documentation.


If there is a term you don’t understand, try to find it in the glossary.

About SAS

If you are looking at a file from SAS and want to know more about its contents, consult the survey data model.


Frequently Asked Questions (FAQ) provides answers to common questions about the SDSS-III, Data Release 10 and our data access tools.


Tutorials provide guidance and hands-on practice in accessing SDSS data for a variety of scientific and teaching tasks.

Contact Us

If you are unable to find answers to your questions on these pages, please email us at the SDSS-III helpdesk, and your question will be directed to a survey expert in the appropriate area.