Comet ISON, C/2012 S1 (ISON): Hubble Telescope Captures First Image Of ISON. Coma Is Already Impressive.
. by Anura Guruge
It is still a long ways out but Solar heat is already causing the frozen matter to sublimate while Solar radiation and wind are creating quite an impressive coma around the nucleus. The tail is also taking shape.
On April 10, 2013 when Hubble took this picture C/2012 S1 was in the process of just crossing Jupiter’s orbital path and was 4.151 AU from the Sun.