On December 21, 2020, Saturn and Jupiter came close together in what is called the Great Conjunction. This happens every 20 years, but this one was much more rare due to how close they came. Saturn and Jupiter were within 0.1 deg. of one another, or 1/5 the apparent diameter of the moon to an observer. The last time they were this close was 400 years ago and couldn't be seen since the planets were in the sky during the day; the last time they were this close and observable was nearly 800 years ago in 1226 A.D. 

A friend and I traveled an hour up into the mountains and sat for two hours in 30° F weather in order to attempt to capture this phenomenon. Unfortunately, clouds in the valley occluded the planets as they came closer to setting, but I was able to get one or two decent shots before they were too hard to see. Another complication was the breeze - even the smallest breeze made my lens shake noticeably at the zoom level I was at. 

I then turned my lens on the moon for the closest shot I've gotten to date. More details in the photos' descriptions.

Jupiter (left) and Saturn (right). Jupiter is much brighter than Saturn, so I brightened up Saturn and slightly darkened Jupiter in this photo, so they could be more equally observed. I also wanted to get another shot with a much increased exposure so the moons could be visible, but by the time I got to that point, the clouds were starting to get in the way.
ISO 200, 1680mm, f/18, 1/13 sec

Waxing Gibbous Moon. This is only very slightly cropped from the original size, mostly to center the moon in the image. My (rented) setup this time was 150-600mm Sigma zoom, 2x Sigma teleconverter, and a 1.4x teleconverter I acquired at the last minute. Combining that with the 1.6x crop factor of my sensor, that is an effective focal length of 2688mm.
ISO 800, 1680mm, f/18, 1/50 sec

Went out again the next night with clear skies in my neighborhood. Much easier to get good shots without the wind, and after having nailed the focusing technique the night before. In this shot, I was able to bring the moons of Jupiter into view. I darkened Saturn some, and Jupiter quite a bit, to facilitate.
ISO 400, 1680mm, f/18, 1/4 sec