Sometimes it pays to return to the places you’ve been before. That’s certainly the case for NASA’s Hubble Space Telescope, which just released an ethereal new image of a strange formation that the agency calls a “Cosmic Sea Lemon” or a “Cosmic Sea Slug” hidden inside a stellar nursery some 5,000 light-years away.
Hubble has seen this formation before. In 1997 the telescope photographed the gassy region inside the Trifid Nebula, which lies within the constellation Sagittarius.
Astronomers decided to re-create the original Hubble image in honor of the 36th anniversary of the space telescope’s launch on April 24, 1990. In the new photograph, the Trifid Nebula is just as cloudy as ever—but there are a few key differences between the two images.
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Images of the Trifid Nebula taken in 2026 (left) and 1997 (right).
NASA/ESA/STScI/Joseph DePasquale/STScI/Jeff Hester/Arizona State University
The formation’s “horn”—a jet of plasma expelled by a protostar—is now noticeably longer than it appeared nearly three decades ago. And a slash of orange and red along the Cosmic Sea Lemon’s “body” appears to have expanded to the right. These subtle changes may help researchers better understand how stars are forming in a notably active stellar nursery.
The image is also a potent reminder of how far Hubble has come. The space telescope was originally expected to operate for about 15 years. But thanks to a few tune-ups, NASA now expects it to continue capturing images of the universe until at least the mid-2030s.