Solar Orbiter to pass through the tails of Comet ATLAS

The European Space Agency's Solar Orbiter, which carries instruments proposed, designed and built at UCL, will cross through the tails of Comet ATLAS during the next few days in a chance encounter flagged to ESA by a team from the UCL Mullard Space Science Laboratory (UCL MSSL). Although the recently launched spacecraft was not due to be taking science data at this time, mission experts have worked to ensure that the four most relevant instruments will be switched on during the unique encounter, including the Solar Wind Analyser (SWA) instrument led by UCL. Solar Orbiter was launched on 10 February 2020. Since then, and with the exception of a brief shutdown due to the coronavirus pandemic, scientists and engineers have been conducting a series of tests and set-up routines known as commissioning. The completion date for this phase was set at 15 June, so that the spacecraft could be fully functional for its first close pass of the Sun, or perihelion, in mid-June. However, the discovery of the chance encounter with the comet made things more urgent. Serendipitously flying through a comet's tail is a rare event for a space mission, something scientists know to have happened only six times before for missions that were not specifically chasing comets.