6 OF THE BEST
iPhone planetarium apps
Apple stargazing apps come with many features, so which one is best for you?
Sky Guide
Price Free; All Constellations art & stories £1.79; Plus £17.99 per year, Pro £34.99 per year
OS minimum version requirement iOS 14.0
Developer Fifth Star Labs
www.fifthstarlabs.com
https://apps.apple.com/gb/app/sky-guide/id576588894
The latest iteration of the Sky Guide app, Version X, sees upgraded visualisations and lots of great background astronomy news. The night sky has more realism than ever, including beautifully rendered pre-dawn light, twilight and dusk, as it takes on a more accurate, practical look than before.
We’re not quite sure, however, how useful it is to point a smartphone at the daytime sky and only get information for the Sun (though you can toggle on and off the ‘stars fade during day’ option). Ditto for some fine but fanciful aurora effects, which can appear on the app when pointed north and south after dark.
As well as a slick and simple design, complete with a cosmic calendar and a weather forecast, the Sky Guide app’s ‘featured’ section contains a mix of excellent news and features by science communicator Dr Jenifer Millard (@ DrJeniMillard on Twitter). The available upgrades increase the number of stars, objects, satellites and zoom power (as well as weather predictions and a dark-sky finder), but the free version – with 24 constellations, 100 deep-sky objects and ISS tracking – is likely to be enough for casual stargazers.
VERDICT
A slick and simple app with an excellent astronomy news and features section. The free version is a great option for casual stargazing.
FOR The basic version is free and visually impressive.
AGAINST Odd aurora effects are misleading.
OVERALL SCORE ★★★★
Stellarium PLUS
Price £11.99
OS minimum version requirement iOS 12.0
Developer Noctua Software
www.noctua-software.com/apps
https://apps.apple.com/gb/app/stellarium-plus/id1458716890
Many amateur astronomers use the free and open source Stellarium planetarium software on their desktop computers, but the developer’s lesser-known apps are just as impressive. A basic free version offers the usual augmented reality experience, with overlaid stars, constellations, planets, comets, satellites and deep-sky objects, while this step-up Stellarium PLUS version –a separate app that costs £11.99 – increases the database from 10th magnitude to 22nd magnitude stars.
Stellarium PLUS is aimed more at telescope owners: it can control a scope using Celestron NexStar, Orion SynScan and LX200 serial protocols and it even simulates what an object will look like through a specific telescope.
The expanded database of stars now includes the new Gaia DR2 catalogue of over 1.69 billion stars, as well as over 10,000 asteroids. As with the desktop version you can zoom in on detailed images of deep-sky objects, and simulate landscapes and Earth’s atmosphere to show realistic sunrises, sunsets and atmospheric refraction. We also love Stellarium’s representations of constellations and asterisms from non-Western cultures.
VERDICT
A familiar experience for users of the desktop version, Stellarium PLUS offers telescope control and a massive database down to 22nd magnitude stars.
FOR Polished, open-source software.
AGAINST Slightly reduced dataset when offline.
OVERALL SCORE ★★★★
GoSky Watch Planetarium
Price £3.49
OS minimum version requirement iOS 9.3
Developer GoSoftWorks
www.gosoftworks.com/apps/goskywatch
https://apps.apple.com/gb/app/goskywatch-planetarium/id284980812
With so many astronomy apps now either costing a lot of money or keeping a lot of features behind in-app purchases, it’s great to see the stargazer-centric GoSkyWatch Planetarium still available for a low price.
It’s got one of the best transitions from portrait to landscape: just swivel a smartphone and the night sky remains serenely still (most stargazing apps reset or refresh). It also has a unique touchless navigation system that makes everything incredibly simple. Instead of the user having to touch an object (and receiving reams of information), this app features a small target circle in the centre of the screen. As you move the phone, stars and planets – even those too dim to see unaided – naturally pass through that circle. As they do, up pops some simple information below the circle, including the name, constellation and how many lightyears away it is. If it’s a planet, a small, image of it rotating briefly appears. Amusingly, it also has a ‘Pluto is a planet’ option.
VERDICT
A uniquely touchless experience and a slick design make this one of the best apps for casual, naked-eye stargazers.
FOR Smooth portrait-to-landscape transitions and touchless navigation.
AGAINST There’s no free option and it only includes stars that are visible to the naked eye.
OVERALL SCORE ★★★★★
Night Sky
Price Free; Premium £4.99 per month or £29.99 per year
OS minimum version requirement iOS 13.0
Developer iCandi Apps
www.icandiapps.com/night-sky-4
https://apps.apple.com/gb/app/night-sky/id475772902
Why not share the night sky? The Night Sky app’s ‘connected stargazing’ feature is a virtual shared stargazing session, allowing members a FaceTime Audio call between iPhones to add stars, planets, constellations and satellites to the session in real time. However, it’s a feature that is only open to Night Sky Premium subscribers (£4.99 per month or £29.99 per year).
Fortunately, this is not the case with another new feature, ‘Sky Tags’, which is free to try out a couple of times: it allows objects in the sky to be saved for future reference and also shared via Apple’s iMessage for others with the Night Sky app to find. As a bonus, you can attach observation notes and even your own astrophotography to each ‘Sky Tag’, which is a nice feature. Meanwhile, ‘Sky Timestamps’ lets you access the sky on specific dates, such as the dates of your next planned star party, but just as impressive is built-in data on local stargazing conditions and an auto-red light mode.
The free version is worth trying out, but the best features do require a subscription.
VERDICT
All-new sharing, virtual stargazing sessions and astrophotography upload, but only if you pay extra.
FOR A clean interface and advanced features.
AGAINST The most useful features require a monthly or annual subscription.
OVERALL SCORE ★★★★
Sky Tonight
Price Free; Premium access £0.79 per month or £4.99 per year
OS minimum version requirement iOS 11.0
Developer Vito Technology
www.starwalk.space/en
https://apps.apple.com/gb/app/sky-tonight-star-gazing-guide/id1570594940
When we are observing in the real world, trees and buildings often get in the way. Cue this well-designed new app’s ‘interactive trajectory’ feature, which will show you the precise movement of a selected object, relative to where you are, for the rest of the night. It’s a powerful addition that, when combined with the app’s ‘AR’ (Augmented Reality) mode, will overlay the sky map on the surroundings using a smartphone’s camera. Meanwhile, on the interactive map, the magnitude limit of what is displayed can be changed using a slider at the bottom of the screen, so it’s obvious what you can see with the naked eye, binoculars and telescopes, respectively.
There’s an easily searchable calendar that presents a list of celestial events that are coming up in the user’s sky, complete with the best observation times, Moon phase and stargazing conditions. All the events can be saved to create an observing list, complete with notifications. This is an impressive free app, but the events are limited to a total of three unless you take out the small Premium subscription.
VERDICT
The app has impressive one-handed operation with uniquely practical features for stargazers and amateur astronomers.
FOR Useful real-world stargazing features.
AGAINST No telescope control features.
OVERALL SCORE ★★★★
SkySafari 7 Plus & Pro
Price Plus £17.99, Pro £21.99
OS minimum version requirement iOS 14.0
Developer Simulation Curriculum Corp
www.skysafariastronomy.com
https://apps.apple.com/gb/app/skysafari-7-plus/id1567654881
This app has been around for years in many guises and it keeps on improving. The very latest version comes in two distinct flavours, Plus and Pro, which cost £17.99 and £21.99 respectively. Please note that it’s not possible to upgrade from one to the other.
So what are the differences? The Plus version shows 2.5 million stars and 32,000 deep-sky objects, while the Pro version reveals 100 million stars, three million galaxies down to 18th magnitude, and 750,000 Solar System objects. Crucially, both play nicely with Wi-Fi-controlled telescopes (via the ASCOM Alpaca and INDI protocols), which puts even the basic Plus version ahead of most other stargazing apps.
Other must-have features on both versions include a ‘Sky Tonight’ area, notifications, a logbook, a stargazing session planning zone and a red-light mode to help your night vision. You can share your observations with others (also using SkySafari) via SkyCast, but we can’t quite see the point of ‘OneSky’, a mode that allows you to see what random other users are observing in real time.
VERDICT
An expensive and impressive toolbox for amateur astronomers, although it takes time to get to know.
FOR Telescope control and hobbyist features.
AGAINST Using the app requires a steep learning curve, and it’s expensive.
OVERALL SCORE ★★★★