NASA's James Webb Space Telescope has imaged PMR 1 — a cloud of gas and dust that strikingly resembles a brain inside a transparent skull, earning it the nickname the "Exposed Cranium" nebula.
The nebula was first observed in infrared light by Webb's predecessor, the now-retired Spitzer Space Telescope, over a decade ago. Webb's two instruments — NIRCam (Near-Infrared Camera) and MIRI (Mid-Infrared Instrument) — now reveal far greater detail.
The images show two distinct regions corresponding to different phases of the nebula's evolution: an outer shell composed mostly of hydrogen, and a more structured inner cloud containing a mix of gases. Both instruments capture a prominent dark lane running vertically through the nebula, dividing it into two brain-like hemispheres. Webb's resolution suggests this lane is linked to jets of material ejected from the central star in opposite directions — particularly visible at the top of the MIRI image, where inner gas appears to be pushed outward.
The nebula is being shaped by a star in its final stages, expelling its outer layers in a process that is rapid by cosmic standards. The star's ultimate fate depends on its mass, which has yet to be determined. If massive enough, it will end in a supernova explosion. A less massive, Sun-like star will continue shedding layers until only a dense white dwarf remains — cooling slowly over billions of years.