On Feb. 25, 2026, NASA and ESA released new James Webb Space Telescope imagery of a tiny, little-studied nebula called PMR 1, now nicknamed the “Exposed Cranium.” In the official write-ups, the object is described as resembling “a brain in a transparent skull,” an uncanny look produced by layered gas, dust, and a striking dark lane that appears to split the inner glow.
Far from being a cosmic oddity for its own sake, the Exposed Cranium Nebula is a snapshot of a star in a late stage of life, actively shedding material into space. Webb’s observations add sharply resolved structure to an object first revealed in infrared more than a decade ago by the (now-retired) Spitzer Space Telescope, turning a faint, intriguing detection into a richly detailed laboratory for stellar mass loss.
1) What Webb actually “revealed” in the Exposed Cranium
PMR 1 sits roughly 5,000 light-years away in the constellation Vela, according to summaries published Feb. 27, 2026, including Scientific American and Space.com. At that distance, even a small nebula can hide complex geometry, especially when dust and gas obscure one another differently across wavelengths.
The Feb. 25, 2026 release (“NASA’s Webb Examines Cranium Nebula”) emphasizes that Webb is targeting a “mysterious, little-studied” nebula surrounding a dying star. The new images show intricate arcs, ripples, and layered shells that were not visible with earlier instruments at the same clarity.
The nickname “Exposed Cranium” isn’t just poetic branding; it reflects the way the nebula’s bright inner structure appears encapsulated by a fainter outer envelope, creating a skull-like outline. This impression is amplified by a dark central lane that divides the luminous interior into two “hemispheres,” a feature that becomes a major clue in interpreting how the star is expelling matter.
2) A dual-instrument view: why NIRCam and MIRI look so different
One of the most important takeaways from the Feb. 25, 2026 materials is that Webb’s Near-Infrared Camera (NIRCam) and Mid-Infrared Instrument (MIRI) produce strongly different views of PMR 1. The split is not a contradiction, it’s the point of multiwavelength astronomy, where different bands trace different components of the same object.
In NIRCam imagery, more stars and background galaxies are visible through and around the nebula. Near-infrared light can reveal fine filaments and contrast effects in the inner regions, making the dark center lane especially noticeable, as also noted on ESA multimedia pages describing the release.
MIRI, by contrast, emphasizes thermal emission from dust: the dust itself glows more strongly at mid-infrared wavelengths, while many background point sources fade. In the ESA “Exposed Cranium Nebula (MIRI image)” page, the agency highlights that MIRI shows more dusty material but fewer stars and galaxies than NIRCam, changing the apparent structure and giving a different read on what’s physically dense versus what’s simply bright in reflected or transmitted light.
3) The dark lane: a “channel,” an outflow, or something else?
The dark lane slicing through the inner nebula is one of the most discussed features in both official releases and media coverage. ESA notes that it is more obvious in NIRCam, while MIRI highlights its apparent role in the ejection of material toward the top and bottom of the structure, suggesting it may be intimately connected to the nebula’s shaping mechanism.
A NASA Webb Telescope quote relayed by NDTV captures the public-facing interpretation: “What looks like a brain is actually a dying star blowing off a shell of gas… The dark lane that divides its ‘hemispheres’ may be related to an outflow from the central star.” In other words, the “gap” may be a pathway carved by moving material, or a region where dust and gas obscure the light differently.
Space.com’s February 2026 explainer adds that the split could reflect polar jets or outflows, but it also underscores uncertainty about the central star’s exact nature, presenting possibilities rather than a settled classification. That uncertainty is scientifically valuable: when the engine driving the structure is not fully pinned down, the nebula becomes a target for follow-up spectroscopy and modeling rather than a closed case.
4) Two distinct regions, two phases: shells that tell a timeline
Webb’s view supports a picture of multiple stages of mass loss. The Feb. 25, 2026 release describes “distinct regions / phases,” including an outer shell that was blown off first and is mostly hydrogen, plus a more structured inner cloud containing a mix of gases.
Scientific American’s Feb. 27, 2026 summary echoes this layered interpretation: the outer layer appears largely hydrogen, while the interior is more complex. That chemical and structural contrast can indicate changes in how the star lost mass over time, whether through steadier winds, episodic pulses, or directional outflows shaped by rotation, magnetism, or a companion.
When astronomers see an older, simpler outer shell wrapped around a younger, more sculpted interior, they often suspect the star’s behavior changed late in life. Webb’s high-resolution infrared imaging provides the kind of detailed morphology needed to test those ideas, because the shapes of filaments and cavities can be compared against simulations of winds, jets, and interacting shells.
5) From Spitzer to Webb: why this is a leap, not just an update
PMR 1 was first revealed in infrared by NASA’s Spitzer Space Telescope more than a decade before Webb’s 2026 images. Spitzer’s discovery context matters: it suggests the nebula is especially telling in infrared, precisely where dust emission and obscured structures become visible.
But Webb’s contribution is not merely a sharper photograph. With far finer structural detail, Webb separates regions that would have blended together in lower-resolution data, turning a general glow into a map of arcs, lanes, and nested shells. That’s essential for determining whether the nebula’s “cranium” appearance is a projection effect (3D structure seen in 2D) or the signature of directional mass loss.
The ESA/Webb photo release (weic2605) explicitly frames the approach as an NIRCam+MIRI observing strategy. It’s the pairing, near-IR sensitivity to fine structure and mid-IR sensitivity to warm dust, that makes the modern dataset more diagnostic than earlier infrared detections alone.
6) Scale, filters, and the people behind the image
Official NASA asset pages provide the practical reading tools that keep a dramatic image scientifically anchored. For the side-by-side “Exposed Cranium Nebula (NIRCam and MIRI)” presentation, NASA includes a compass, scale, and filter details; the scale bar is listed as 0.5 light-years / 20 arcseconds.
Those filter sets matter because they define what the colors are tracing, specific infrared bands that emphasize different emissions and dust features. While the public may remember the “brain” resemblance, researchers focus on how each filter highlights different components that can be tied back to physical conditions and composition.
The credits also show how modern astronomy is a blend of engineering, observation, and communication. Across official pages, the imagery is credited to NASA/ESA/CSA/STScI, with image processing by Joseph DePasquale (STScI). Processing does not “invent” features; it translates calibrated data into a view where structures and contrasts can be interpreted, especially important when comparing NIRCam and MIRI, where the same region can look radically different.
7) What happens next for the star, and why that answer depends on mass
The February 2026 coverage, both official and in media summaries, repeats a central framing: the star at the heart of PMR 1 is shedding layers in a late evolutionary stage. In that sense, the Exposed Cranium Nebula is not a static object but a transient phase, a record of material recently expelled into interstellar space.
Its ultimate fate depends on the star’s mass. If the star is massive enough, it may eventually end in a supernova; if not, it will likely leave behind a white dwarf after casting off its outer layers. This broad mass-dependent fork is widely cited because it connects the nebula’s beauty to a fundamental stellar outcome, either a quiet compact remnant or a catastrophic explosion.
Yet the same reports emphasize that details remain uncertain, especially regarding the central star’s nature and how, exactly, the inner structures were sculpted. That uncertainty is precisely why Webb’s multiwavelength imagery is valuable: it can guide follow-up observations aimed at measuring composition, temperature, density, and motion, turning the “exposed cranium” into a testbed for how dying stars return material to the galaxy.
Webb’s Exposed Cranium Nebula images show how a single object can look like two different nebulae depending on how you observe it: NIRCam reveals a busier background and sharper contrast in the inner lane, while MIRI elevates the warm dust that reshapes the perceived anatomy. Together, the two views make PMR 1 feel less like a novelty and more like a case study in the physics of stellar shedding.
From Spitzer’s earlier infrared detection to Webb’s 2026 dual-instrument portrait, PMR 1 has evolved from a faint curiosity into a finely resolved scene of layered shells, mixed gases, and possible outflows. The “brain in a transparent skull” is ultimately a reminder of what nebulae are: not clouds for their own sake, but the visible consequences of stars changing state, and of the material they return to space to seed future generations of stars and planets.
