NASA’s Hubble Dazzles With Young Stars in Trifid Nebula

This shimmering region of star-formation, a close-up of the Trifid Nebula about 5,000 light-years from Earth, was captured in intricate detail by NASA’s Hubble Space Telescope. The colors in Hubble’s visible light image, which marks the 36th anniversary of the mission’s launch on April 24, are reminiscent of an underwater scene filled with fine-grained sediments fluttering through the ocean’s depths.

Several massive stars, which are outside this field of view, have shaped this region for at least 300,000 years. (See them in a wider view.) Their powerful winds continue to blow an enormous bubble, a small portion of which is shown here, that pushes and compresses the cloud’s gas and dust, triggering new waves of star formation.

This isn’t the first time Hubble has gazed at this scene. The telescope observed the Trifid in 1997 and now, 29 years later, it has leveraged almost its full operational lifetime to show us changes in the nebula on human time scales. Why look at the same location again? In addition to seeing changes over time, Hubble is also equipped with an improved camera with a wider field of view and greater sensitivity that was installed during Servicing Mission 4.

Hubble’s view of the Trifid Nebula (also known as Messier 20 or M20) focuses on a “head” and undulating “body” of a rusty-colored cloud of gas and dust that resembles a marine sea lemon, or sea slug, that appears as if it is gliding through the cosmos.

The Cosmic Sea Lemon’s left “horn” is part of Herbig-Haro 399, a jet of plasma periodically ejected over centuries by a young protostar embedded in the head of the sea lemon. Changes, as seen in the video below, allow researchers to measure the speeds of the outflows and determine how much energy the protostar is injecting into these regions. These measurements will provide insights into how newly formed stars interact with their surroundings.

To the immediate lower right is evidence of the counter jet: jagged orange and red lines that ”run” down the back of the sea lemon’s neck, where a natural V appears in the brown dust.

The darker, more triangular “horn” on the right of the “head” hosts another young star at its tip. Zoom in to see a faint red dot with a tiny jet. The green arc above it may be evidence that a circumstellar disk is being eroded by the intense ultraviolet light from nearby massive stars. The clearer area around this protostar suggests it may almost be finished forming.

To the immediate left of the Cosmic Sea Lemon is a small, faint pillar that resembles a water bear. Much of this pillar’s gas and dust has been blown away, but the densest material at the top persists.

Streaks and sharp lines offer more clues about other young stars’ activities. Spy an example by looking near the center for a rippling angled line that begins in a bright orange and ends in a blazing red. In the image comparison, it appears to move, which means it may be a jet shot out by another actively forming star buried deeply in dust.

In Hubble’s visible light observations, the clearest view is toward the top left, where it’s bluer. Strong ultraviolet light from massive stars, not in the field of view, stripped electrons from nearby gas, creating a glow, with winds sculpting a bubble by clearing out surrounding dust.

At the top of the Cosmic Sea Lemon’s head, bright yellow gas streams upward. This is an example of ultraviolet light plowing into the dark brown dust, stripping and dismantling the gas and dust.

Many ridges and slopes of dark brown material will remain for a few million years, as the stars’ ultraviolet light slowly eats away at the gas. The densest areas are home to protostars, which are obscured in visible light.

The far-right corner is nearly pitch black. This is where the dust is the densest. The stars that appear here may not be part of this star-forming region — they might be closer to us, in the foreground.

Now, scan the scene for bright orange orbs. These stars have fully formed, clearing the space around them. Over millions of years, the nebula’s gas and dust will disappear — only stars will remain.

Hubble’s varied instruments and the expansive range of light it collects — from ultraviolet through visible to near-infrared — have helped researchers make ground-breaking discoveries for decades and supply new data daily that will inevitably lead to more.

The telescope has taken over 1.7 million observations to date. Almost 29,000 astronomers have published peer-reviewed science papers using Hubble data collected over the telescope’s 36-year lifetime, resulting in more than 23,000 publications, with almost 1,100 in 2025 alone. Hubble’s observational data is publicly available in the Barbara A. Mikulski Archive for Space Telescopes at the Space Telescope Science Institute in Baltimore, while its mission descriptions, history, and gallery of popular images are found on NASA’s Hubble website.

Since 2022, researchers have regularly combined Hubble’s observations with those from NASA’s James Webb Space Telescope to push opportunities for discovery further. Very soon, astronomers will begin diving into huge near-infrared datasets from vast surveys from NASA’s new Nancy Grace Roman Space Telescope, and will seek to compare them to existing or new Hubble observations to clarify what is at work. For context, Roman’s camera can cover the entire Trifid Nebula, showing the full bubble, with a single pointing — and may turn up interesting objects for follow-up.

Another flagship to look forward to? The mission concept known as the Habitable Worlds Observatory, which would have a significantly larger mirror than Hubble — leading to higher resolution images — and, like Hubble, capture ultraviolet, visible, and infrared light. This next-generation space telescope would advance science across all of astrophysics, and would be the first specifically engineered telescope to identify habitable, Earth-like planets next to relatively bright stars like our Sun and examine them for evidence of life.

The Hubble Space Telescope has been operating for over three decades and continues to make ground-breaking discoveries that shape our fundamental understanding of the universe. Hubble is a project of international cooperation between NASA and ESA (European Space Agency). NASA’s Goddard Space Flight Center in Greenbelt, Maryland, manages the telescope and mission operations. Lockheed Martin Space, based in Denver, also supports mission operations at Goddard. The Space Telescope Science Institute in Baltimore, which is operated by the Association of Universities for Research in Astronomy, conducts Hubble science operations for NASA.