NASA’s Solar Dynamics Observatory (SDO) is celebrating ten trips around the sun this year—that is, ten years of being the sun’s most reliable photographer. The satellite has been taking a snapshot of the fiery ball of gas at the center of our solar system every 0.75 seconds since its launch on February 11, 2010.
All told, SDO has captured more than 425 million high-resolution images of the sun, amounting to more than 20 million gigabytes of data, according to a NASA statement. This month, scientists at the Goddard Space Flight Center used that massive stockpile of images to stitch together a one-hour-long timelapse video of the sun’s surface, where each second corresponds to about one day on Earth. The video gives viewers a sped-up look at the sun’s last decade, set to a custom soundtrack by musician Lars Leonhard.
As the images flicker, sunspots—the dark, cooler patches on the sun’s outer layer where magnetic fields are the strongest—appear and fade over time. Solar flares arc over the sun’s corona, the burning hot outermost layer of gas in its atmosphere. As Victoria Jaggard reported for Smithsonian magazine in 2014, solar flares are large bursts of radiation that occur when magnetic energy is released from the sun’s surface.
The sun goes through a roughly 11-year cycle of activity, as Nicholas St. Fleur explained in the New York Times in 2017. During solar minimum, the sun’s surface is relatively quiet, with few sunspots or solar flares; during solar maximum, sunspots and solar flares abound.
In the video, viewers can watch as activity on the sun’s surface intensifies until its peak in 2014, when the star reached solar maximum, and then quiets down in the following years as the sun cycles back toward its minimum.
Highlights in the footage include a shot of a massive prominence eruption exploding out of the sun on June 7, 2011, around the 6:20 minute mark. On June 5, 2012, at the 12:14 minute mark, Venus transited the face of the sun—“an event so rare it won’t happen again until 2117,” according to another highlight reel from NASA’s Goddard Space Flight Center.
On October 8, 2014, at the 26:39 minute mark, active regions on the sun’s surface “resemble a jack o’ lantern just in time for Halloween,” according to NASA’s description. Mercury transited the sun’s surface on May 9, 2016 (36:18 minute mark) and again on November 11, 2019 (57:38 minute mark).
Last June, NASA announced that the sun had produced its biggest solar flare since 2017, which could be a sign that the sun has passed its solar minimum and is “waking up” from its cyclical slumber, as Smithsonian magazine reported at the time.
SDO orbits at roughly 22,000 miles above the surface in a geosynchronous orbit, according to its website. NASA plans to keep observing the sun with SDO for at least another three years, according to its statement.