This picture, assembled from data from the WISPR instrument on the Parker Solar Probe, shows the twin tails of Comet NEOWISE as seen on 5 July, 2020. The lower, broader tail is the comet’s dust tail, while the thinner, upper tail is the comet’s ion tail.
The dust tail is created by dust lifting off the surface of the comet’s nucleus, and it trails behind the comet in its orbit. The ion tail is made up of gases that have been ionized by stripped of electrons by the Sun’s intense light. These ionized gases are buffeted by the solar wind, the Sun’s constant outflow of magnetized material, forcing the ion tail to extend directly away from the Sun. The Sun is out of the image to the left.
Image Credits: NASA / JHUAPL / NRL / Parker Solar Probe / Guillermo Stenborg