A flash of lightning, and then – something else. High above the storm, a crimson figure blinks in and out of existence. If you saw it, you are a lucky witness of a sprite, one of the least-understood electrical phenomena in Earth’s upper atmosphere. But if you caught it on camera, your photo could contribute to a ground-breaking scientific discovery.
NASA’s newest citizen science project, Spritacular (pronounced sprite–tacular), leverages the power of crowdsourcing to advance the study of sprites and other Transient Luminous Events, or TLEs. TLEs include a range of electrical phenomena that occur above thunderstorms and produce brief flashes of light. The new citizen science project aims to connect professional scientists with members of the public who would like their camerawork to contribute to scientific studies.
“People capture wonderful images of sprites, but they’re shared sporadically over the internet and most of the scientific community is unaware of these captures,” said Dr. Burcu Kosar, a space physicist at NASA’s Goddard Space Flight Center in Greenbelt, Maryland and Spritacular principal investigator. “Spritacular will bridge this gap by creating the first crowdsourced database of sprites and other TLEs that is accessible and readily available for scientific research.”
Sprites occur at some 50 miles (80 kilometers) altitude, high above thunderstorms. They appear moments after a lightning strike – a sudden reddish flash that can take a range of shapes, often combining diffuse plumes and bright, spiny tendrils. Some sprites tend to dance over the storms, turning on and off one after another. Many questions about how and why they form remain unanswered.
Eyewitness reports of strange flashes of light above thunderstorms date back hundreds of years, but it wasn’t until 1989 that the first such event was caught on camera. Researchers from the University of Minnesota were testing a low-light TV camera for an upcoming rocket flight mission. By sheer accident, their camera captured the very first credible evidence for what we now call sprites.
“It wasn’t a very high resolution or fast camera – they just captured two luminous blobs above a nearby thunderstorm,” Kosar said. “The whole field was kickstarted because a camera was pointed in the right direction at the right time.”
Scientists dubbed these elusive events “sprites,” a reference to mythical fairy-like creatures from European folklore. As other kinds of TLEs were discovered, the playful naming convention stuck. Today, scientists study ELVES, Halos, Blue Jets, Gigantic Jets, and more.
Yet we still have far too few observations of sprites and other TLEs, and there is much we don’t know. Some of the major outstanding questions include:
- How often do sprites occur? Why do they take the shapes they do?
- What conditions in the upper atmosphere trigger sprite initiation?
- How do sprites affect Earth’s global electric circuit, and what is their contribution to the energy in Earth’s upper atmosphere?
- How are sprites connected with gravity waves, which send wind-driven ripples of energy through our upper atmosphere?
Answering these questions could lead to major advances in the science of Earth’s upper atmosphere. But to get there, Spritacular needs your help!
Become a Spritacular Citizen Scientist
The first goal of Spritacular is to build an image database: A collection of observations of sprites and other TLEs that will help answer the questions above.
Many commercially available, digital single-lens reflex (DSLR) cameras are suitable for capturing sprites. The hardest part is knowing when and where to look. By bringing together experienced “sprite-chasers” and providing educational support and resources, Spritacular aims to provide all the guidance you need for a successful capture.
If you believe you have captured a photo of a sprite or other TLEs, you can create an account and then submit your photos and photo details (time and location of the photo) to Spritacular. Accurate time and location details are preferred, but approximate time and location will also be accepted with sufficient detail. To submit a photo, you must be the photographer who captured it.
All submitted photos will be reviewed by scientists. Submitters who collaborate with scientists and whose image leads to a scientific study or discovery will be properly acknowledged or listed as a coauthor on the resulting scientific publication, depending on the level of contribution.
The broader goal of Spritacular is to foster a mutual exchange between observers of TLEs and the scientific community and to inspire citizen scientists all around the world to participate in the investigation of these elusive events. As the Spritacular community and image database grows, Kosar is planning to implement new software tools to automatically cross-reference submissions with databases on lightning and thunderstorms. These tools will allow users to analyze their own images and contribute to the scientific method.
Spritacular is a NASA-funded citizen science project in collaboration with the Catholic University of America in Washington, D.C. The principal Investigator is Dr. Burcu Kosar and Co-Investigator is Dr. Jia Yue.
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By Miles Hatfield
NASA’s Goddard Space Flight Center, Greenbelt, MD.