The fragmented remains of Comet C/2019 Y4 (ATLAS) imaged with the Hubble Space Telescope on April 23, 2020. (NASA/ESA and STScI)
(News from ESA)
ESA’s Solar Orbiter will cross through the tails of Comet ATLAS during the next few days. 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.
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. All such encounters have been discovered in the spacecraft data after the event. Solar Orbiter’s upcoming crossing is the first to be predicted in advance.
Solar Orbiter is equipped with a suite of 10 in-situ and remote-sensing instruments to investigate the Sun and the flow of charged particles it releases into space – the solar wind. Fortuitously, the four in-situ instruments are also perfect for detecting the comet’s tails because they measure the conditions around the spacecraft, and so they could return data about the dust grains and the electrically ...