Email Print Share
July 6, 2005

Blue jet lightning

This is the first image ever captured of blue jet lightning. It was taken at Arecibo Observatory in Puerto Rico, a National Science Foundation (NSF)-supported facility.

More about this Image
A team of researchers at Arecibo captured video evidence from the ground of this lightning phenomenon known as blue jet. The discovery is the first ground-based evidence linking the ionosphere with cloud tops in blue jet events.

According to Victor Pasko of Penn State University, an electrical engineer working at Arecibo, pilots and others reported observations of red sprites and blue jets long before the first one was captured on video, and numerous undocumented reports of similar phenomena have appeared in scientific literature for over a century.

Blue jets develop on the tops of cloud formations at altitudes of 12 to about 26 miles high. They appear blue to the naked eye, can last for up to several hundreds of milliseconds and are cone-shaped. According to Sunanda Basu, a program director in NSF's Division of Atmospheric Sciences (which funded the research), the video is the first ground-based evidence of a direct electrical discharge from a thundercloud top to the lower edge of the Earth's ionosphere. The electrical contact may represent an important component of the global electrical circuit, says Basu.

The event was recorded using a monochrome, low-light video system, but the researchers all agree that the phenomena was seen visually as blue in color. The top of the jet appears to look much more like a red sprite than a blue jet, with hot spots and a fuzzy diffused appearance. Scientists do not yet know if this is a new phenomenon. (Date of Image: Unknown)

Credit: Victor Pasko, Penn State University

Images and other media in the National Science Foundation Multimedia Gallery are available for use in print and electronic material by NSF employees, members of the media, university staff, teachers and the general public. All media in the gallery are intended for personal, educational and nonprofit/non-commercial use only.

Images credited to the National Science Foundation, a federal agency, are in the public domain. The images were created by employees of the United States Government as part of their official duties or prepared by contractors as "works for hire" for NSF. You may freely use NSF-credited images and, at your discretion, credit NSF with a "Courtesy: National Science Foundation" notation.

Additional information about general usage can be found in Conditions.

Also Available:
Download the high-resolution JPG version of the image. (690 KB)

Use your mouse to right-click (Mac users may need to Ctrl-click) the link above and choose the option that will save the file or target to your computer.