"Keep right" signs aren't just all over U.S. roads. One "sign" appeared at least briefly at the center of the solar system last week.
The formation on the sun appeared to resemble a cosmic "keep right" sign -- or the school of pointing fish in "Finding Nemo."
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The "arrows" were made by two solar filaments, or clouds of solar material held in place by magnetic force. While unstable, some formations can stay in place for days or weeks, NASA said.
These filaments can also erupt, with the solar material either raining back down onto the sun or shooting out into space as a coronal mass ejection.
The image above was taken on May 28 in combined wavelengths of extreme ultraviolet light by NASA's Solar Dynamics Observatory, which keeps watch over the sun's activities.