Hubble revisited the aquatic-looking Trifid Nebula 30 years after its original observations. (Image credit: NASA, ESA, STScI. Image processing: J. DePasquale (STScI))

Quick facts

What it is: Trifid Nebula (Messier 20)

Where it is: 5,000 light-years from Earth in the constellation Sagittarius

When it was shared: April 20, 2026

There are speckles, horns, and a series of colorful, glowing ridges. No, it's not an underwater creature — it's the latest breathtaking portrait of the Trifid Nebula, captured by the Hubble Space Telescope.

This nebula, also known as Messier 20, is a star-forming region located around 5,000 light-years from Earth in the constellation Sagittarius. Nicknamed the "Cosmic Sea Lemon," this zoomed-in portion of the nebula tells a story of the tantrums of young, massive stars blowing a giant bubble of gas and dust. This region is home to several stellar giants (not captured in this field of view) that have sculpted this region for at least 300,000 years.

What makes this image even more special is that Hubble first photographed this exact scene back in 1997 using its Wide Field and Planetary Camera 2. Now, 29 years later, Hubble took a second look at this stunning scenery for its 36th anniversary — this time, with its more powerful Wide Field Camera 3.

An annotated image of the Trifid Nebula, showing the jet and possible counter-jet being spat out by a young star. (Image credit: NASA, ESA, STScI. Image processing: J. DePasquale (STScI))

In the new image, the mesmerizing orange cloud linings show where powerful ultraviolet radiation from massive stars has stripped electrons from nearby gas, making it glow. Their stellar winds have cleared some surrounding dust, as shown in the bright-blue area where the dust is thinnest. The far-right corner — nearly pitch-black — is where the dust is densest.

The prominent brown-shaped structure in the center left of the image is the "head" of the cosmic sea lemon. Its "body" is a rust-colored cloud of gas. Between two "horns," yellow gas splashes outward like the glow of a volcano's lava, almost as if something were being destroyed there. And that is exactly what's happening; these are regions where the ultraviolet light is eroding gas and dust, according to the European Space Agency.

The main peak, seen left of the sea lemon's head, is accompanied by a jet of energetic gas. This region is part of the Herbig-Haro (HH) object called HH-399, and the jet is ejected by a baby star located within the sea lemon's head. (HH objects are bright regions of nebulosity created by the powerful jets of newborn stars.)

Comparing the new observations with the 1997 image, researchers actually watched the jet expand. This change will allow scientists to estimate the jet's speed, revealing how much energy the young star is injecting into its surroundings. There is also a thick streak of material in bright orange and blazing red that appears to expand to the right — potentially a jet shooting from another newly formed star.

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The bright-orange stars scattered across the scene have already won their battle against the nebula. They are fully formed, and their light and stellar winds have cleared the space around them. Over the next few million years, the remaining stars buried in the nebula will do the same. The gas and dust will slowly disappear, and only stars will remain.

With this image, Hubble not only celebrates 36 years of operations but also puts its improved capabilities on full display. The newly operational Vera C. Rubin Observatory, located in Chile's Atacama Desert, also captured the Trifid Nebula, looking like a giant cloud of cotton candy, in its first batch of images.