STEREO-A watches Comet Leonard

The Heliospheric Imager (HI) instrument on NASA’s STEREO-A satellite has been watching comet Leonard since early November 2021, and was well-placed to capture images of the comet as it brightened in December. These very sensitive cameras observed the comet’s extremely long ion tail interacting with the solar wind and solar outflows, providing valuable context for the Solar Orbiter observations.