A serendipitous flythrough of the tail of a disintegrated comet has actually provided researchers a unique chance to study these impressive structures, in brand-new research study provided today at the National Astronomy Meeting 2021.
Comet ATLAS fragmented prior to its closest method to the Sun in 2015, leaving its previous tail routing through area in the kind of wispy clouds of dust and charged particles. The disintegration was observed by the Hubble Space Telescope in April 2020, however more just recently the ESA spacecraft Solar Orbiter has actually flown near the tail residues in the course of its continuous objective.
This fortunate encounter has actually provided scientists with a unique chance to examine the structure of a separated cometary tail. Using combined measurements from all of Solar Orbiter’s in-situ instruments, the researchers have actually rebuilded the encounter with ATLAS’s tail. The resulting design shows that the ambient interplanetary electromagnetic field brought by the solar wind ‘drapes’ around the comet, and surrounds a main tail area with a weaker electromagnetic field.
Comets are usually identified by 2 different tails; one is the popular intense and curved dust tail, the other — usually fainter — is the ion tail. The ion tail stems from the interaction in between the cometary gas and the surrounding solar wind, the hot gas of charged particles that continuously blows from the Sun and penetrates the entire Solar System.
When the solar wind engages with a strong barrier, like a comet, its electromagnetic field is believed to flex and ‘drape’ around it. The synchronised existence of electromagnetic field draping and cometary ions launched by the melting of the icy nucleus then produces the particular 2nd ion tail, which can extend for big ranges downstream from the comet’s nucleus.
Lorenzo Matteini, a solar physicist at Imperial College London and leader of the work, states: “This is quite a unique event, and an exciting opportunity for us to study the makeup and structure of comet tails in unprecedented detail. Hopefully, with the Parker Solar Probe and Solar Orbiter now orbiting the Sun closer than ever before, these events may become much more common in the future!”
This is the very first comet tail detection taking place so near the Sun — well inside the orbit of Venus. It is likewise among the really couple of cases where researchers have actually had the ability to make direct measurements from a fragmented comet. Data from this encounter is anticipated to contribute significantly to our understanding of the interaction of comets with the solar wind and the structure and development of their ion tails.
Meeting: Royal Astronomical Society National Astronomy Meeting