Comet C/2020 F3 (NEOWISE)

Comet Neowise was discovered on March 27,2020 by astronomers operating NASA’s Near-Earth Object Wide-field Infrared Survey Explorer (NEOWISE) spacecraft. At that time, it was at magnitude 18. It was not expected to get much brighter than 9th or 10th magnitude. Typical of the unpredictability of comets, on June 7 it had increased to a magnitude 7.2. Beginning July 1, amateur astronomers made sightings of the comet before sunrise with estimates of magnitude near +1, bright enough to be plainly visible to the naked eye.

Naked eye comets are fairly uncommon. During an average human lifespan, you may get a chance to see about four. The last naked eye comet visible in the Northern Hemisphere was the great Hale-Bopp in 1997.

Because it had "come out of nowhere", I was caught a little flatfooted and did not have access to my dark sky sight the week of July 12 when the comet was at its brightest in the sky before sunrise. But thankfully, after the comet had swung around the sun and into the evening sky, I got a clear night to observe and photograph it on July 20. On that date, the comet was 0.70 astronomical units from earth, 2 days from its closest approach (0.69 AU on July 22; an AU is the distance from the earth to the Sun, about 93 million miles).

The photograph clearly shows the comet has 2 "tails". Pushed out by the pressure of sunlight itself, the comet's broad, yellowish dust tail is easiest to see. This tail curves as heavier dust particles are better able to resist this light pressure and continue along a solar orbit. The fainter blue tail is an ion tail, formed as ions from the cometary coma are dragged outward by magnetic fields in the solar wind and fluoresce in the sunlight. The coma (nucleus) of the comet displays a green/teal color; this is because the coma contains cyanogen and diatomic carbon, which glow green in the sunlight (comets are one of the very few astrophotography targets to display the color green).

On most nights when doing astrophotography, I take brief glimpses of the night sky. But this night was different. The sky was very dark since it was the night of the new moon. While the equipment was doing its thing, I could not stop staring up. The Milky Way stretched like a canopy overhead. Jupiter and Saturn shone like beacons in the southeast. And comet Neowise adorned the northwest sporting a magnificent tail. While doing so, it occurred to me that a chapter in my life had closed. As a 14 year old, I became interested in astronomy and astrophotography after seeing an article about Comet Kohoutek, which was predicted to be the "Comet of the Century", but I never saw it because it seriously underperformed, and I stopped pursuing the hobby. It took me about 30 years to get involved again. And here I was, 47 years later, finally viewing and photographing a naked eye comet at a dark sky site.