Photo of Planet Uranus Taken With off-the-Shelf Cell Phone
By: John Clark Craig
Tags: Astronomy, Cell Phones, Python, Astrophotography, Amateur Astronomy

Pictures of Uranus are tricky, but yes, it’s very true

My goal is to photograph the trails of satellites in the night sky, with known stars in the background, to enable analysis with Python scripts to calculate things like altitude, velocity, and other parameters. My passion is using Python for creative and fun real-world applications, and this night-sky application seemed like a good challenge.

Photo by Usukhbayar Gankhuyag on Unsplash

Updated Camera

About a week ago I traded up my phone for a Samsung Galaxy S20 Ultra model. I chose this phone for its cameras, although there are several other phones available with similar capabilities suitable for various types of simple astrophotography. I wasn’t sure if any of today’s phones would be up to the task of capturing stars and satellites, but I was in for a pleasant surprise!

Photo by Jonas Leupe on Unsplash

Finding a Dark Sky Location

Last night was our first drive out of town to find better dark sky conditions, with the hope of catching a satellite or two. (The Python scripts are yet to be written, but stay tuned as I plan to present some code in the next few days.) The night was a huge success, as the photographs showed many more stars than we could see with the naked eye, and we caught several satellites that we were able to clearly identify with the aid of the online Stellarium program.

Even as the Sun was setting we captured many stars in our photographs

For example, we could clearly see the constellation Cassiopeia with the naked eye, but the photographs revealed many more stars in that part of the sky than we had expected. Here’s a comparison of a zoom in on one small part of a photo with a screen grab of Cassiopeia from Stellarium:

A small part of a photo showing Cassiopeia

Courtesy Stellarium online app

It’s tricky to do the photograph justice here in this online article, but it is very possible in the original photo to see many faint stars that perfectly match those shown in the online Stellarium app as you zoom in on the same part of the night sky. Notice that even the M31 galaxy is visible in the photo as a faint smudge.

Camera Setup

To capture these photos I put my Samsung Galaxy S20 Ultra camera into Pro mode, manually set the focus to infinity, the ISO to 1600 (it can go up to 3200 on this camera), the exposure to 8 seconds, and the aspect ratio to 4:3. I used a tripod, as this is an absolute necessity to get clear 8 second exposures.

Photo by Ben Collins on Unsplash — Any astrophotography requires a tripod

We came home with a couple dozen photographs, several showing Russian, U.S., and even Egyptian satellite trails. Again, stay tuned for a future article showing how we verified these satellites, and how we can do interesting calculations on those photos. But the story doesn’t stop there!

Fun Facts About Uranus

Uranus is an ice giant planet almost 20 times further from the Sun as the Earth, and its diameter is only 4 times that of the Earth. Jupiter is almost 3 times bigger than Uranus, and it’s only about 5 times as far from the Sun as the Earth. Uranus takes 84 Earth years to orbit the Sun just once. Jupiter is easy to see in the night sky, but Uranus is smaller, much further away, and it sits far out there in much dimmer sunlight. It really is hard to see, or photograph.

Planet Uranus fact: It’s almost exactly 4 times the diameter of the Earth

Catching Uranus in a Photograph

While studying the various photographs against the Stellarium display, I noticed that Uranus was marked in a position that should be in one of the photos. Sure enough, when I zoomed in on that part of the photo, the dim white dot of Uranus was there! Uranus is normally nearly impossible to see with the naked eye, or to photograph with off-the-shelf cameras without special lenses and filters, so I was totally impressed and blown away with this discovery.

Courtesy Stellarium online app