Celestron StarSense Explorer - What's the best one for you?

Celestron StarSense Explorer Model Guide

The StarSense Explorer range from Celestron is no doubt the bestselling line-up of telescopes in the world. They've helped turn complete novices into keen star gazers, delighted families and found homes with the young and young at heart. 

Plus, it's not just beginners - many have found a home with more experienced observers who want something ultra simple to setup and transport with just enough tech to assist without it getting in the way.

There are a few different options in the StarSense Explorer range and this is a quick explainer to help you decide the best one for you (and maybe some hints about selecting telescopes in general.)

With all of these telescopes you'll be able to see planets such as Saturn, Jupiter and Mars but as we like to point out, there's much to observe beyond the Solar System. You will easily view other deep-sky astro objects such as nebulae, star clusters and much more.

All StarSense Explorer telescopes use Celestron's technology to help you find objects in the night sky using your Android phone or Apple iPhone.  Think of it being similar to the maps system in your car.  StarSense Explorer doesn't control your telescope, rather it tells you where to move it to so you can find what you're looking for.

For example, you've heard the Great Orion Nebula is worth a squizz, so you put that into the StarSense app on your phone attached to the telescope and it will put arrows on the screen to show you where to move the telescope to find 

If you are not sure what to look for, the StarSense Explorer app can take you on a personalised tour of "what's up" for your location. You also don't need Wi-Fi or even a 4G/5G connection. All the data you need is loaded onto your phone when you install the app. You can head away the bush to observe the night sky without having to worry about needing a phone signal. 

First up: how do we measure telescopes?

The main thing a telescope does is collect light and either concentrate it on an observers eyeball or camera sensor. The tiny Celestron FirstScope and the Hubble Space Telescope both work on the same principle.  

The width of its main lens or mirror - also called the aperture - is one of the main contributors to how powerful a telescope is. Basically, the larger the aperture the more light it collects. This lets the telescope see things that are fainter and in more detail. 

For example, the Celestron StarSense Explorer LT70 AZ is the introduction to the range and its lens has diameter of 70mm. It's also one of our most popular telescopes. By comparison the "lens" at the front of your eye has a diameter of about 7mm.

Celestron StarSense Explorer LT70 AZ

This means the StarSense Explorer LT70 AZ can see collect about 100 times as much as your eye can, letting it see things that are too faint to be seen with your eyes alone.

A slightly larger and more expensive model is the Celestron StarSense Explorer LT80 AZ.  This has a 80mm aperture lens. You might think "why am paying for such a tiny increase in size? It's only centimetre bigger!" 

Yes, it's one 1cm larger in size, but compared to the 70mm lens, the 80mm has a 30% larger surface area in total. This mean is doesn't collect 100 times as much light as your eye, but rather about 130 times - a very useful bump in capability if it's within your budget.

Reflector vs Refractor

You'll notice two types of Celestron StarSense Explorer telescopes. The LT70 AZ and LT80 AZ are refractor type telescopes. They have lens at the front of the telescope and you view through the other end. 

The StarSense LT114 AZ and LT127 AZ models use curved, parabolic mirror at the end of the tube. It collects and concentrates the light and then use a small mirror at 45 degree angle to view at the side of the tube.

This style of telescope is often called a Newtonian Reflector as it was invented by Sir Isaac Newton back in 1668. The design was so effective, we still use it today!

Why use a mirror?

The main reason Sir Isaac came up with his design back in the day was to avoid the colour fringes around objects that were common with early refractor telescopes.  We can now get around this with refractor telescope by using a more complex lens, however it costs much less per cm of aperture to make a reflecting telescope.  The LT114 AZ telescope has a mirror 114cm across and you can probably guess what the size of the mirror in the LT127 AZ. In much the same way the amount of light captured by the LT80 AZ is greater than the LT70 AZ, the larger telescope collects more light and will let you "see" more. 

Reflecting telescopes like these produce an image that's upside down. There zero problems with this when looking at objects in space, however it's less than ideal for things on planet Earth.

The Celestron StarSense Explorer LT70 AZ and LT80 AZ will also produce an image that's the right way up.  This is something you might want to consider if you're planning on using your Celestron telescope for viewing scenery or say whale watching. 

Another model is the even larger DX130 telescope.

Celestron StarSense Explorer DX130 Newtonian Telescope

This has a 130mm aperture main mirror that collects more than 340 times the amount of light compared to the human eye, so the reason for observing with a larger telescope is images will be brighter and clearer.  What can be seen will in the StarSense Explorer LT70 AZ will be more detailed in the DX130 and there's things that you'll see that are too faint to be seen in the smaller LT70 AZ. 

The DX130 also has a sturdier tripod as well as slow motion control for fine tuning the movement of the telescope. 

Another option is the tabletop versions of the StarSense Explorer range. 

Celestron StarSense Explorer 130mm Tabletop Dobsonian Telescope

If you have a solid picnic table or outdoor place to put these telescopes onto, their Dobsonian mounts will provide a smooth movement and rock steady viewing.