NASA’s Parker Solar Probe mission has given scientists the first complete look at Venus’ orbital dust ring, a collection of microscopic dust particles that circulates around the Sun along Venus’ orbit. Though earlier missions have made some observations of Venus’ orbital dust ring, Parker Solar Probe’s images are the first to show the planet’s dust ring for nearly its entire 360-degree span around the Sun.
Parker Solar Probe’s WISPR instrument — short for Wide-field Imager for Solar Probe — is designed to study the solar wind, the Sun’s constantly outflowing material. Space is teeming with dust, which reflects so much light that it typically shines at least a hundred times brighter than the solar wind. (The light reflected from space dust is what creates the zodiacal light, sometimes visible from Earth as a faint column of light rising upward from the horizon.)
In order to see the solar wind with WISPR, scientists use image processing to remove the dust background and stars from the images. This process worked so well that Venus’ orbital dust ring — which appears as a bright band stretching across the images — was subtracted as well. It wasn’t until Parker Solar Probe performed rolling maneuvers to manage its momentum on its way to its next solar flyby, which changed the orientation of its cameras, that the static dust ring was noticed by scientists. Based on the relative brightness, scientists estimate that the dust along Venus’ orbit is about 10% more dense than in neighboring regions. The results were published on April 7, 2021, in The Astrophysical Journal. Read more about Parker Solar Probe’s observations from the Johns Hopkins University Applied Physics Laboratory, which designed, built, and operates the spacecraft.