Credit: NASA/JPL-Caltech

This all-sky mosaic image from NASAs SPHEREx space telescope was collected between May and December 2025 and features a small selection of the 102 infrared colors the observatory can detect. Infrared colors are invisible to the human eye but are represented here in visible colors. The infrared colors included in these images were selected to highlight the presence of stars (blue, green, and white), hot hydrogen gas (blue), and cosmic dust (red). The bright feature running through the middle of the images is the Milky Way Galaxy, lit up by billions of stars within it. Most of the points of light above and below it are other galaxies.

The prominent red clouds are a type of cosmic dust known as polycyclic aromatic hydrocarbons (PAHs), a common ingredient in the formation of stars and planets. This dust primarily emits one wavelength of light around 3.4 microns. The bubbles of hot hydrogen gas (blue), corresponds to a wavelength of around 4 microns.

Breaking the light from cosmic objects into its constituent wavelengths is a technique called spectroscopy. The image here illustrates one primary use of spectroscopy, which is to identify the presence of certain chemical elements. Other wavelengths of light observed by SPHEREx reveal the presence of water ice, carbon dioxide ice, and carbon monoxide ice. With its all-sky view, the observatory will help scientists measure the large-scale distribution of these materials in the Milky Way galaxy. These chemicals are all building blocks of organic material, and essential for the formation of life as we know it.

Spectroscopy can also be used to measure the distances to other galaxies, and SPHEREx will measure the 3D distribution of hundreds of millions of galaxies in our universe. With this new map, scientists will learn more about a dramatic cosmic event called inflation that occurred in the first billionth of a trillionth of a trillionth of a second after the big bang. That event subtly influenced the large-scale distribution of those galaxies, and SPHERExs all-sky spectral map will lend new insight into the physics of inflation.

In order to make the file sizes smaller, the spatial resolution of these images has been reduced by a factor of one thousand from the full-resolution SPHEREx data images.

The elliptical projection used in this image encompasses the entire visible sky.

Provider: SPHEREx

Image Source: https://www.spherex.caltech.edu/image/spherex20251218a-spherex-all-sky-map-2025

Curator: SPHEREx at Caltech, Pasadena, CA, United States