史汪彗星的离子彗尾
2020 April 29 The Ion Tail of New Comet SWAN Image Credit & Copyright: Gerald Rhemann Explanation: Newly discovered Comet SWAN has already developed an impressive tail. The comet came in from the outer Solar System and has just passed inside the orbit of the Earth. Officially designated C/2020 F8 (SWAN), this outgassing interplanetary iceberg will pass its closest to the Earth on May 13, and closest to the Sun on May 27. The comet was first noticed in late March by an astronomy enthusiast looking through images taken by NASA’s Sun-orbiting SOHO spacecraft, and is named for this spacecraft’s Solar Wind Anisotropies (SWAN) camera. The featured image, taken from the dark skies in Namibia in mid-April, captured Comet SWAN’s green-glowing coma and unexpectedly long,…