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PHYS 1411: Introduction to Astronomy: Web Resources

How to Measure to Spin of a Black Hole

How to Measure the Spin of a Black Hole

By NASA/JPL-Caltech [Public domain], via Wikimedia Commons

Evaluating Websites

Have you ever used the CRAAP test?

If you are using a website for research--whether is it being used to get some background information, learn more about a topic, or being used in a paper (if your professor allows)--you want to find GOOD and RELIABLE websites.  You want to evaluate them for credibility and appropriateness.  There are a lot of websites out there that promote misinformation, are not fact-checked, or are just opinion pieces (to note a few examples of unreliable information).  You might read and consider an opinion piece in your personal life, but for the most part it will not be used in the academic sciences. 

Not sure how to evaluate websites to find good information?  Follow the CRAAP test!

The CRAAP test asks you to evaluate sources based on three criteria:

  • Currency--The timeliness of the information (how current is it?)
  • Relevance--The importance of the information for your needs
  • Authority--The source of the information
  • Accuracy--The reliability, truthfulness, and correctness of the information
  • Purpose--the reason the information exists

To learn more about how to use the CRAAP test, such as questions to ask yourself as you encounter websites, see this handout developed by librarians at California State University--Chico.

Web Resources

NASA Astrophysics (NASA): A NASA page that includes links to their overviews of Dark Energy, Dark Matter, Black Holes, The Big Bang, Galaxies, Stars, and Exoplanets.

Solar System Exploration (NASA): A NASA page dedicated to our solar system.  There is information on the individual planets including "Planet X".  If you click the planets tab at the top of the page you can also find additional webpages dedicated to other objects in the solar system such as the Oort Cloud.

Stellar Evolution Infographic (NASA): An infographic showing the evolution of stars.  It goes beyond just what would happen to our sun.  Useful visual aid to understand the evolution of stars.


'The light from those millions of stars you see is probably many thousands of years old' is a rare example of laypeople substantially OVERestimating astronomical numbers.

Randall Monroe via (Creative Commons)

Finding Reliable Web Resources

One way to find websites that are reliable (can be trusted to have true information) is to use Operators as well as other search tricks.  These operators allow you to tailor your search to retrieve better results.  The image below shows one of the most useful operators as well as another trick to help you search.  Other common operators can be found HERE.

In the image, there is an operator site: You can use this operator to tailor your search to particular types of sites such as educational institutions (edu), organizations (org), or government institutions (gov).  These are three most common types of sites you would find reliable information on. 

The other thing to note below is that the phrase medical terminology is written with quotes around it.  This tells Google that you only want results back that have the phrase medical terminology.  Without those quotes Google may retrieve websites that have the words medical and terminology but not as a phrase.  This allows you to find more relevant information.