NASAさんのインスタグラム写真 - (NASAInstagram)「Nope, you’re not seeing double — comet NEOWISE has two tails. This unique view of comet NEOWISE comes from @nasa’s Parker Solar Probe spacecraft, which was speeding away from the Sun as it took this image on July 5. The comet was discovered by NASA’s Near-Earth Object Wide-field Infrared Survey Explorer, or NEOWISE, in March 2020. Like other comets, comet NEOWISE has both a dust tail and an ion tail. Both tails are visible in this image because of Parker Solar Probe’s viewing angle to the comet. The dust tail (the lower tail in this image) is created when dust lifts off the surface of the comet’s nucleus and trails behind the comet in its orbit. Scientists hope to use Parker Solar Probe’s images to study the size of dust grains within the dust tail, as well as the rate at which the comet sheds dust. The ion tail (the upper tail in this image) is made up of gases that have been ionized by losing electrons in the Sun’s intense light. These ionized gases are buffeted by the solar wind — the Sun’s constant outflow of magnetized material — creating the ion tail that extends directly away from the Sun. Parker Solar Probe’s images appear to show a divide in the ion tail. This could mean that comet NEOWISE has two ion tails, in addition to its dust tail, though scientists would need more data and analysis to confirm this possibility. Follow the link in our bio to read more. Image credits: NASA/Johns Hopkins APL/Naval Research Lab/Parker Solar Probe/Brendan Gallagher #nasa #space #science #comets #neowise」7月11日 0時53分