Credit: NASA/JPL-Caltech/IPAC

At first glance this image might look like the glow of aurorae in the night sky, but it actually reveals patterns of wispy dust that fills the space between stars. This region of sky in the constellation of Aries covers a large swath of sky, about as wide as the span of 11 full moons. When viewed in visible light we see only a myriad of stars, but the infrared view provided by NASA’s WISE reveals a delicate field of cloudy dust structures. This is an example of what astronomers dubbed “infrared cirrus” after its discovery 40 years ago by the Infrared Astronomical Satellite (IRAS). And while its similarity to aurorae may only be coincidental, the patterns seen here are likely also influenced by the effect of magnetic fields in our galaxy.

These dust clouds fill the spaces between stars. The faint glow of starlight that permeates interstellar space can excite the glow of carbon-rich dust molecules, known as polycyclic aromatic hydrocarbons (PAHs), which are particularly bright at wavelengths of light around 12 microns, here represented as green. The wispy shapes trace out the flow of interstellar gas and dust.

The dim linear band of infrared light running diagonally from the middle left to the lower right side of the field comes from a source much closer to home, within our own solar system. Known as “zodiacal dust,” it fills the flat disk defined by the orbits of the inner planets and asteroids. This material is produced from collisions of asteroids and the passage of comets, objects that were the focus of the NEOWISE mission, the 2013 reactivation of the retired WISE spacecraft.

This image uses data from the original cryogenic phase of the WISE mission. Infrared wavelengths of 3.4 & 4.6 microns are displayed in blue and cyan, respectively, and are dominated by the glow of stars. Light with a wavelength of 12 microns is displayed in green and traces the presence of carbon-rich dust known as polycyclic aromatic hydrocarbons (PAHs). The 22 micron light is rendered in red and is dominated by the thermal glow of warm dust.

Provider: Wide-field Infrared Survey Explorer

Image Source: /image/wise/WISE2024-02

Curator: Wide-field Infrared Survey Explorer