Photographing Comet Neowise

This July we were treated to a once in a generation event in the night sky: the brightest comet in the northern hemisphere since Comet Hale-Bopp in 1997 - Comet Neowise.

C/2020 F3 (NEOWISE) was discovered only months earlier on March 27 2020 by astronomers from the Wide-field Infared Survey Explorer (WISE) during the NEOWISE program, the namesake of the comet. But by the summer, the comet could be seen in the morning sky just above the north-eastern horizon and had brightened dramatically.

Unfortunately, the weather had been less kind to me and other hopeful skywatchers in the United Kingdom and Ireland. Sightings of the comet have been inhibited seemingly never-ending cloud cover. But then, in the early hours of the 12th July, our patience was rewarded with a rare break in the clouds. Finally, the deep ocean blues of the summer sky was lit up with the the sight of neowise juxtaposed with the shimmering wisps of noctilucent clouds. A palette of blues with scintillating whites dancing across it. Not only was this a rare astronomical event with the presence of Comet Neowise, but this was the brightest display of noctilucent clouds for some time.

Panorama stitched together from 5 different images featuring Comet Neowise and noctilucent clouds.

Noctilucent clouds are composed of tiny ice crystals in the upper atmosphere making them the highest clouds of any kind in the Earth’s atmosphere. They are only visible during astronomical twilight when the sun is below the horizon and usually seen during the summer months in latitudes between 50 and 70 degrees.

Comet Neowise is on a near parabolic orbit and passed perihelion - the point of closest approach to the sun - at a distance of 103 million km on July 3rd. Its closest approach to Earth, meanwhile, occurred on the 23rd July while it was seen in the constellation of Ursa Major. It’s common for comets to break up as they pass through Perihelion due to the heat of the Sun. Neowise, on the other hand, survived this point continued to brighten and became one of the most infamous comets of the past two decades. During this period, including the nights I was photographing it, the comet tracked just below the Plough and eventually dimmed by the end of July.

The central solid structure of the comet is known as the nucleus. It is typically composed of rock and frozen gases but when this is heated by the sun, the frozen gases sublimate to form an atmosphere that surrounds the nucleus called a coma. Comet Neowise’s nucleus is only around 5km across but the coma that forms around the surface is so bright the it can’t be seen directly. Furthermore, radiation pressure and solar wind exert a large force on this coma to cause the large tail seen in the pictures. This dust trail is in fact one of two tails first seen accompanying Neowise it also has a prominent blue ion tail composed of ionised gas that is blown back by solar winds. This can be observed in images taken with more specialised astrophotography equipment that can perform longer exposures of the night sky. A further sodium tail has also been confirmed subsequently be observers at the Planetary Science Institute’s Input/Output facility.

Unfortunately Comet Neowise is on a 6,800-year orbit around the sun so we will have to wait nearly 7,000 years for it to return. Until then, I hope you enjoy my images.

C/2020 F3, it’s been a pleasure.

Nikon DS5600

Sigma 20 mm f/1.4 DG HSM AF-P DX Lens

NIKKOR 18-55mm f/3.5-5.6G VR Lens

Images captured in my Bortle 4 skies in Shropshire. Processed with Starry Landscape Stacker Lightroom, Photoshop and Topaz DeNoise AI.

Follow @leather_ben on Instagram to learn more and if you have any questions about astrophotography or my images, don’t be afraid to message me!