ESA | Solar Orbiter | 2020 May 29
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 charged particles given off by the comet. These emissions create the comet’s two tails: the dust tail that is left behind in the comet’s orbit and the ion tail that points straight away from the Sun.
Solar Orbiter will cross the ion tail of Comet ATLAS on 31 May–1 June, and the dust tail on 6 June. If the ion tail is dense enough, Solar Orbiter’s magnetometer (MAG) might detect the variation of the interplanetary magnetic field because of its interaction with ions in the comet’s tail, while the Solar Wind Analyser (SWA) could directly capture some of the tail particles.
When Solar Orbiter crosses the dust tail, depending on its density – which is extremely difficult to predict – it is possible that one or more tiny dust grains may hit the spacecraft at speeds of tens of kilometres per second. While there is no significant risk to the spacecraft from this, the dust grains themselves will be vaporised on impact, forming tiny clouds of electrically charged gas, or plasma, which could be detected by the Radio and Plasma Waves (RPW) instrument. ...
Prospects for the In Situ detection of Comet C/2019 Y4 ATLAS by Solar Orbiter ~ Geraint H. Jones, Qasim Afghan, Oliver Price
- Research Notes of the AAS 4(5):62 (2020 May) DOI: 10.3847/2515-5172/ab8fa6
- arXiv.org > astro-ph > arXiv:2005.03806 > 08 May 2020