Longest known comet tail stretched for over a billion kilometres

NASA’s Cassini spacecraft crossed paths with the elongated tail of a comet in 2002, picking up hydrogen ions from over a billion kilometres away

Source:
https://www.newscientist.com/article/2245355-longest-known-comet-tail-stretched-for-over-a-billion-kilometres/?utm_campaign=RSS%7CNSNS&utm_source=NSNS&utm_medium=RSS&utm_content=home