The Ultimate Guide to viewing the Planets

A Beginner’s Guide to viewing the Planets from Ireland: How to Spot Our Cosmic Neighbours

Understanding the Basics

Before you start your planetary viewing journey, it's important to understand the basics first. The five planets that are visible to the naked eye from Ireland without any telescope or equipment are Mercury, Venus, Mars, Jupiter, and Saturn. These planets are usually relatively bright in the sky - in fact in many cases some of them are often mistaken for a bright stars. The planets Uranus and Neptune are of course also visible, but are much further away and can generally not be seen with the naked eye but require the use of a good telescope.

Timing is key

The time of year plays a crucial role in viewing the planets because each planet has its own specific orbit around the sun and will therefore be only visible in the night sky at certain times of the year. This is where a good planetarium APP is very useful as it will tell you exactly when and where to look to see them - 'more on this below'

Location

As the planets are much closer to Earth and relatively bright in comparison to other objects in space, light pollution is not something you really need to worry about. Even if you're in a large town or city such as Dublin, Cork or Galway for example, you can still clearly see the planets with the naked eye or through a telescope.

How to view them

So you may be wondering how do I find the planets in the night sky amongst all those stars? Well its actually a lot easier than you might think. As the majority of the planets are generally fairly bright, you just need to know when and which direction to look to have a really good chance of spotting them. In addition to this, many of them have some pretty distinguishable features which we will explain below.

Recommended starting point is to download a smartphone planetarium APP such as 'Stellarium' (which is FREE to download and use - suitable on both Android and Apple devices). This is the best way to locate them and get confirmation whether you are looking at a planet or a bright star. Its also lots of fun to use too for the family and will also show how to find other deep space objects such as galaxies and nebula. While there is a paid version of the APP for more advanced features, don't worry as you'll have more than enough features using the the FREE version to find different objects in space such as the planets.

Once you're all setup and ready to go, you can check the APP to see if any of the planets are currently visible in the sky from your location at that exact moment and if not, when they will be visible to see.

REMEMBER - don't worry if you don't have a telescope or binoculars right now, even with the naked eye, there is something quite magical about looking into the sky and realising that the object you are looking at is another world in our Solar System!

Here's a brief explanation of how 'Stellarium' works below:

After you enter your present location, time and date, Stellarium can accurately show what deepspace objects are in the sky from your location at that exact moment. Just enter an object in the search bar and while holding your phone towards the sky, simply follow the arrow on the virtual planetarium to find it, as shown in the images below.

Now you have located it, you can sit back and take in the fact that you are right now viewing another planet in our Solar System - that's pretty impressive! Of course if you have some binoculars or a good quality telescope you can use Stellarium to show you where to point them and really dial in the details further. While Binoculars will still help, a telescope will really allow you to experience features of the planets that you probably never expected such as the rings of Saturn or the moons and cloud bands of Jupiter. 

If you have never seen the planets through a telescope, we promise, you won't be disappointed!. Its quite a memorable experience, even with a good beginner telescope and its hard to ever forget moments like that.

So you live somewhere in rural Ireland or even one of the larger towns -
lets go through the main planets you can see with the naked eye:

Planet Mercury: Mercury is normally visible in the morning or the evening, depending on the time of year. Its not especially bright but when its visible in the sky its usually very low on the horizon (East or West) and is one of the few bright star like objects that you can see at that time of the morning or evening - which makes it easier to spot. 

Planet Venus: Again like Mercury its usually only visible in the evening or the early morning but its BY FAR the brightest star in the sky, in fact the planet Venus is brighter than any other object in the sky - You definitely won't miss this planet when its in view! Its so bright many people often mistake it for a plane when they first see it.

Planet Mars: Mars is also relatively bright, similar to many of the other brighter stars but what gives it away is its red/orange colour which really stands out amongst the other stars, making it quite easy to spot when you know the approximate location in the sky.

Above: A photo of Mars under a bright Moon as it would be seen in the night sky (taken with a Nikon D3500 DSLR camera) © Horizon Astronomy

Planet Jupiter: This is the second brightest planet (after Venus) and again is extremely easy to find. While Venus dominates the sky at sunrise and sunset, Jupiter is the brightest object in the sky at night. As its such a huge planet, you can see some incredible details on Jupiter using a very modest telescope or even Binoculars - some of its larger moons are sometimes visible next to it and appear as bright points of light when viewed using Binoculars.

Planet Saturn: The planet Saturn is relatively bright but not as bright as Jupiter. It has a very definite cream/yellow colour and once you know the approximate location in the sky, its generally quite easy to pick out among the other stars. What's fascinating though with Saturn (like Jupiter too) is the amount of detail you can see even with good binoculars or a beginner telescope. While it won't be very big using a small telescope, you can still quite easily make out the shape of the rings.

Planetary Events

Another thrilling experience are special planetary events such as Oppositions and Conjunctions -  During an Opposition, a planet is directly opposite the Sun in relation to Earth, making it appear brighter as its at its closest point to us.

Conjunctions on the other hand occur when two or more planets appear close together in the sky. Some common planetary conjunctions are 'Mars + Jupiter' and 'Venus + Jupiter (Which is very impressive as they are both so bright)' as well as 'Venus + Mercury (which can sometimes happen several times a year)'.

Taking things to the next level - Using a Telescope.

Viewing the planets using a Telescope really changes everything as even a small but good quality beginner telescope can reveal details you probably wouldn't expect. Using a smaller telescope, the best planets to view are Venus, Mars Jupiter and Saturn (Mercury can also be seen but as its so tiny, it wont reveal any real detail and will still appear as a bright star). To view Uranus and Neptune we recommend a larger Telescope such as an 8" aperture or bigger. (Although you can still see them with smaller telescopes as a small green/aqua coloured star)

What you can expect to see through a small beginner telescope:

Mars: Mars will appear as a very small but bright orange glowing disc through a small telescope and the best time to view it is during its opposition (closest point to earth). We also recommend using a more powerful eyepiece like a 6mm eyepiece and even a x2 Barlow lens . Its also very bright which can wash out some of the visible details but as mentioned above for Venus, planetary filters really tone this down and dramatically improve the contrast and in fact if the atmospheric conditions are good enough and with enough magnification, it can also be possible to see the polar ice caps on Mars at certain times of the year.

Above: Some actual photos of Mars, Jupiter and Saturn taken through a small beginner telescope to give you an idea of the scale of the planets through a small telescope (Telescope used: Bresser Messier Nano AR-80/640 and a x2 barlow lens) - © Horizon Astronomy

Jupiter: Without a doubt one of the big favourites (along with Saturn) to view with a small telescope. The planet Jupiter is simply huge, its also very bright and even with some of our good entry level telescopes and a higher powered eyepiece, you will clearly make out the planet as a small but bright disc with two distinctive bands across the middle (Jupiter's two main cloud bands). Actually if the conditions are good enough and with some planetary filters to increase the contrast, you can sometimes make out the 'Great red spot' on Jupiter - A huge raging storm that's over twice the size of planet Earth. You'll normally also see some of its larger moons and these will appear as bright points of light to either side of it and its fascinating to view Jupiter over several hours to see how the moons move and change position.

Saturn: Like Jupiter, Saturn is a real treasure to see through a small telescope. Although you won't see much detail on the planet itself, you will be able to make out the shape of its famous rings. Again a stronger eyepiece and even a barlow lens is recommended for viewing Saturn too as its extremely far away and will benefit greatly with a little more magnification. Saturn is also extremely bright when viewed through the eyepiece and can appear almost white when viewed without filters.

Uranus (Recommended for larger Telescopes): Although Uranus is a very large planet, its distance is simply 'mind blowing' to comprehend (approx. 2.9 billion kilometers away) so at this distance you need a larger dedicated planetary telescope (or a large Dobsonian - 8" or bigger) to make out a clear disc shape. With a larger telescope it will appear as a pale aqua coloured disc - which is really impressive to see!

Neptune (Recommended for larger Telescopes): Neptune sits even further away than Uranus and orbits our sun at an even more 'incomprehensible' 4.5 billion kilometers away from Earth. Through a larger telescope, again a dedicated planetary telescope or 8" Dobsonian or bigger - Neptune will appear as a pale green coloured disc. Viewing this planet with your own eyes, as it sits right at the edge of our solar system is really amazing to see and a 'must-do' if you have a suitable telescope.

Final Thoughts: So as you can see, to view the planets, you don't necessarily need a telescope because even seeing the planets with your own eyes is a really great and highly recommended experience. However if you have one, naturally a small beginner telescope will begin to provide some extraordinary details of our neighbours in the Solar System and this is one of the best introductions to planetary Astronomy.

While pretty much all telescopes are suitable for viewing the planets, if specifically viewing the planets (and the Moon!) is your ultimate goal in Astronomy then there are some specific characteristics to look out for when purchasing a telescope - We've listed some of them below.

Ideal Telescope characteristics for viewing the planets:

1. More Aperture & Longer Focal length = More Clarity & Resolution (therefore better at high magnifications)
2. A good solid Mount: This is really important for all telescopes but especially at higher magnification. (This prevents the object shaking in the eyepiece at high magnifications, which can make focusing and viewing extremely difficult.)

As an example, we've included some photos below which were taken using our more advanced 'Specialised' planetary telescope at our 'Horizon Observatory' in Southern Germany. These telescopes are of course well beyond the scope of beginner level (*and not meant to be representative of what you can see through a small beginner telescope) - but fascinating to see nonetheless.

Below: Some actual photos of Mars, Jupiter and Saturn taken using specialised a 6" Classic Cassegrain Planetary Telescope and a dedicated Astro-camera on an EXOS-2 Mount - © Horizon Astronomy

So now you know how to find the planets and what kind of views you can expect to see.

We hope you found this guide useful and as always feel free to contact us at sales@horizonastronomy.ie (or send us a quick 'Whats APP' Message) if you have any questions about anything in this article or need some Telescope advice.

Clear Skies!