Comet Neowise and its ion tail

Although it is growing fainter day by day (around third magnitude last night) the comet has grown two impressive, long tails. The one we've all been looking at is the whitish dust tail, made up of silicate dust that has 'boiled off' the surface of the comet. For the first time last night I managed to photograph the second, blueish ion tail.This is composed of ionised gases - chiefly carbon monoxide, carbon dioxide and nitrogen - the CO+ absorbs sunlight, fluorescing it as blue light. The ion tail points directly away from the Sun, whereas the dust tail is pushed away from the comet's nucleus by the solar wind and radiation pressure. The dust tail reflects sunlight, so is typically white or yellowish. Neowise is getting quite high in the sky and is just below the familiar constellation 'the Plough' (Ursa Major)

Lots of other good stuff to see last night: the four Galilean satellites of Jupiter were strung out in a line with two either side of the giant planet, while the ISS occulted Arcturus and nearly did the same to Vega!