Astronomy Challenge: Observing the Moons of Uranus

My first ever astronomy challenge piece challenges you to observe the moons of Uranus, since Uranus is a dim planet out in the outer reaches of our solar system about 1.5 billion kilometres from the Sun.

You would receive about 400th the light on Uranus compared to Earth, which means that everything out there would be a great deal dimmer. With the naked eye, the planet is currently visible at magnitude 5.7 in the constellation Aries, and will move into Taurus over the next few years. The planet is brightening as well as it approaches perihelion which will do so around the year 2050.

It is possible to view the planet itself with binoculars or a small telescope, in which case the planet will appear as a small blue disc, but this is a challenge and we are not really interested in the planet itself but in the moons. A telescope with an aperture of eight-inches can be used to view some of the moons, including the brightest, Titania, at magnitude 13.8.

But hold on do not worry I will get to doing this challenge in small telescopes in a little while.

To view Oberon which is further out than Titania you can use a 10 or 12 inch telescope but there are actually similarly bright moons of Uranus that are closer in and in fact there's five moons of Uranus that you can view potentially within with a telescope visually.

But the problem becomes that Uranus itself is too bright, which is quite ironic. The glare of the planet manages to hide the moons that are closest to the planet so how do you deal with this?

Tips and Tricks on viewing the Moons of Uranus

So you really need to try and time your viewing of the moons correctly. So that they are at the point in their orbit where the furthest away from the planet as possible and that is a real challenge.

Another possibility is to try and look at the moons through a high magnification some people have managed up to 350 times magnification to try and increase the contrast between the planet and the moons. If so you would want to use a high powered wide angle eyepiece to observe as much of the surrounding area as possible.

Another technique that can be used is an occulting bar which is as simple as a piece of wire that you can put across the eyepiece to try and block the glare of the planet.

Now of course it is all well and good saying just use a larger telescope but that is not much of a challenge. But so also if you want to try and capture the moons of Uranus in a smaller telescope then you can use a camera and that is what I have done myself.

I have not got an eight-inch telescope, I have a six-inch telescope but using a camera you can increase the exposure length and by increasing it just up to five to ten seconds as I did you can start to see the moons emerge from the from the darkness.

Of course, the problem with this is that the longer you expose the image the brighter Uranus gets in the actual image so you will need a way of somehow overcoming that if you want to capture more moons. As of now I have only managed to capture Titania and Oberon. They are the easiest to capture since they are some of the brightest of the moons, as well as being quite far from the planet itself. While there are similar ones in brightness, they are also closer so they fall under the glare of Uranus.

Another potential approach is to try and capture the moons in the infra red. I haven't tried this myself so if anyone has any success please leave a comment below.

I find that this tool is great to confirm that you have seen the moons of Uranus at any particular point in time.

Now I really want these astronomy challenges to be interactive and for you to take us apart in them as much as possible so if you have any images or drawings that you want to submit then please submit them to this shared google album where you can post those as well as very short videos do not submit anything too massive!

In submitting images or videos so you give permission for those videos and photos and so on to be used in a later episode, if there are enough responses sent in. If you have any observations notes then please in the comments below and I will also include those in the video if you like.

To see what I managed to capture using my six-inch telescope please watch the episode below.

I get commissions for purchases made through affiliate links in this article.