English: It is never safe to look directly at the sun's rays - even if the sun is partly obscured. When watching a partial eclipse you must wear eclipse glasses at all times if you want to face the sun, or use an alternate indirect method. This also applies during a total eclipse up until the time when the sun is completely and totally blocked.

During the short time when the moon completely obscures the sun - known as the period of totality - it is safe to look directly at the star, but it's crucial that you know when to take off and put back on your glasses.

First and foremost: Check for local information on timing of when the total eclipse will begin and end. NASA's page of eclipse times is a good place to start.

Second: The sun also provides important clues for when totality is about to start and end.

Learn more at https://eclipse2017.nasa.gov

Credit: NASA's Goddard Space Flight Center

Find more videos about the solar ecilpse at https://svs.gsfc.nasa.gov/Gallery/suneclipse2017.html

This video is public domain and along with other supporting visualizations can be downloaded from the Scientific Visualization Studio at: https://svs.gsfc.nasa.gov/12637

If you liked this video, subscribe to the NASA Goddard YouTube channel: https://www.youtube.com/NASAExplorer

Or subscribe to NASA’s Goddard Shorts HD Podcast: https://svs.gsfc.nasa.gov/vis/iTunes/f0004_index.html

Follow NASA’s Goddard Space Flight Center · Facebook: https://www.facebook.com/NASA.GSFC · Twitter https://twitter.com/NASAGoddard · Flickr https://www.flickr.com/photos/gsfc/ · Instagram https://www.instagram.com/nasagoddard/

· Google+ https://plus.google.com/+NASAGoddard/posts