Jupiter has been at opposition lately and closer to the Earth than it usually is and has thus has been quite bright in the night sky lately. Jupiter at opposition means that the Earth is directly between Jupiter and the Sun and not only is the Earth as close to Jupiter as it gets, but the Earth-facing side of Jupiter is fully lit by the sun so it is one of the brightest objects in the night sky. Jupiter is in opposition with the Earth about once every 13 months. Below is a photo of Jupiter taken by the NASA space probe Juno which is currently orbiting Jupiter.

Jupiter was at maximum opposition on September 26, but the night of September 27 it occurred to me to go out into my driveway a little after 10:00PM and have a look. Jupiter, being the largest planet in the solar system, was very bright and easy to find on the clear night, but to the un-aided eye it still just looks like a bright star. So I wondered what I could get if I shot it with my camera and a 400mm lens. Turns out, a lot.

When I initially set my camera up and focused, I was amazed that I could not only see Jupiter but four of its moons as well. So, I had to take some photos. The main consideration is that with a 400mm focal length, I would have to be shooting well under a second shutter speed to avoid motion blur as the Earth rotates. With a 1/15s exposure and f/5.6, ISO800 I was just able get Jupiter and its four main moons without too much noticeable blur. Jupiter has dozens of moons, but there are four relatively big moons that are most noticeable. The image below is a crop of the original image.

The problem with exposing enough to get the moons is that Jupiter is completely over-exposed. Jupiter is more than 1000 times the size of the Earth and reflects a lot of sunlight, but the four moons are much smaller than the Earth and don’t reflect nearly as much light as Jupiter. So I decided I would figure out a good exposure for Jupiter and see if I could get some interesting detail.

With a good exposure I was surprisingly able to get some of the characteristic banding of Jupiter, but the moons were now too faint to show up. So, I decided to merge the photos in Photoshop to see if I could get the entire family. I opened both images as layers in Photoshop and masked out the overexposed Jupiter and then aligned the properly exposed Jupiter in the image underneath it. I had to work on the glare and save the nearby moon, but I think I got a pretty good merge.

So, there is a pixelated Jupiter and it’s four largest moons Io, Europa, Ganymede, and Callisto as taken by a full-frame camera and 400mm lens from 400,000,000 miles away. It’s no impressive telescope picture, but it was fun to do.