Skip to main content
U.S. flag

An official website of the United States government

Official websites use .gov
A .gov website belongs to an official government organization in the United States.

Secure .gov websites use HTTPS
A lock ( ) or https:// means you’ve safely connected to the .gov website. Share sensitive information only on official, secure websites.

Spotlight: Geomagnetic Storm Creates Bright Northern Lights While Also Affecting NIST’s Cesium Clocks

A photo of the night sky with greenish lights on the right.
Credit: Courtesy of Rebecca Jacobson

Did you see the northern lights recently? NIST’s cesium fountain clocks did.

Coronal mass ejections on the Sun sent waves of highly energized particles crashing into the Earth’s atmosphere over the weekend of May 10. This geomagnetic storm created the bright aurora borealis that was seen across all 50 United States, including Hawai‘i, according to NOAA’s Space Weather Prediction Center. NOAA rated this storm a G5, the strongest on its scale. 

Storms of this magnitude interfere with the Earth’s magnetic field. The storm was so intense that NIST’s cesium fountain clocks, NIST-F3 and F4, directly sensed the variation of 0.1% in Earth’s magnetic field due to the storm. That was surprising — both clocks have layers of magnetic shielding to block out environmental effects like geomagnetic storms. 

But don’t worry, NIST is well prepared for these events and applied a correction to the clocks to compensate, so we could keep civilian time ticking without interruption.

Follow us on social media for more like this from all across NIST!

Released May 21, 2024