Can iOS devices really be useful astronomy companions? Christian Hall turns his iPad and iPhone to the sky to find out

Astronomy For iPhone : There’s no better place to start in amateur astronomy than with a cheap refractor telescope and a paper planisphere to hold up to the sky. Well, we’d agree if this was still 2007! Ever since then the world of astronomy has changed dramatically thanks to the App Store, giving you the power to not only locate stars, but to learn all sorts of facts and figures by pointing your device at the night sky.

Astronomy has found a new audience thanks to some incredible apps made using the same data that’s behind some of the world’s most expensive telescopes. Yet these apps cost just a few pounds. Even desktop stargazing software never gets that cheap! But are these apps just educational tools or practical astronomy assistants? The answer is a bit of both. You obviously still need a telescope or large binoculars to see the true majestic beauty of the night sky, but iOS apps are perfect for guiding your viewing and saving you time in locating and exploring parts of the cosmos.

We’ve concentrated on star mapping apps that show you the current positions of stars and planets in their constellations, but some are better than others for locating deep sky objects such as nebulae. Brian Cox wannabees read on!

Controlling telescopes with stargazing a pps

More expensive apps such as SkySafari 3 Pro (£27.99) can also double up as a control interface for your ‘go-to’ telescope. Such apps can point a ‘go-to’ telescope anywhere in the sky, using Wi-Fi or via a specialist connection kit like Southern Star’s SkyWire lead (http://www. southernstars.com/products/ skywire/index.html). A wide variety of telescope brands are supported by such accessories and if you needed proof that iOS devices are being taken seriously by the astronomy community then these tie-in products are it. If using the apps we’ve mentioned here get you hooked on the stars then consider the ‘go-to’ option if you want to use your iOS device to the max.

GoSkyWatch Planetarium for iPad

Handily the perfect entry point for newcomers to iOS astronomy is a free app

GoSkyWatch’s overall design and depictions of the constellations might not be as attractive as some of ether apps on show here, but it’s a very useful and accurate navigation tool that uses a star lock on feature to really good effect. Unlike most star mapping apps, GoSkyWatch’s locator is a targeting ring in the centre of the screen, which makes selecting the star a lot easier than most other planetarium apps where it’s very common to press on the wrong thing with your finger.

GoSkyWatch also has a really useful thumbnail feature which shows you a small image of the object you’re actually observing, be it a major star, planet, star cluster or nebula. The targeting ring also has crosshairs which are used to display additional information. The name of the constellation you’re in is displayed at the bottom, the celestial coordinates to the left and the area on the right is populated by the object’s name once you centre something in the ring. The search features are superb and for the planets and the Moon there’s real-time distance calculators and altitude charts for the day. It’s also available as a universal app for £2.49, but if you’ve got an iPad just go for this brilliant free introduction to iOS astronomy.

Star Walk

This showcase app for the original iPad really shows off the night sky in all its wonder

Star Walk was one of the first serious astronomy apps to emerge on the App Store and it continues to be well supported with regular updates. With an iOS device that sports a camera, Star Walk allows for an overlay of the real night sky that you see with a graphical representation layered on top of it. It’s a great use of augmented reality and is the finest example of it in an astronomy app. The app’s overall design and graphical representations are stunning and the addition of a bit of colour to the night sky really helps newcomers engage with the heavens, getting away from all that black! The spiral arm of the Milky Way that you can see from Earth is wonderfully recreated here and inadvertently helps make navigating the constellations easier. There’s also a night viewing mode which turns the screen red to help your eyes maintain their ‘dark vision’ when observing outside.

One of the standout features of Star Walk is Sky Live, which can be called up from the menu in the bottom-right of the interface and also shows up when you launch the app. It shows you key information for observing the Moon and planets in real-time from your present location. A recent update has also animated this menu for extra flair! A handy video tutorial is also now included in the app to help you get the most out of your stargazing.

Redshift – Astronomy

This good alternative to Sky Walk has a few unique features but it costs a bit more

As with GoSkyWatch Planetarium a star targeting guide is used in the centre of the screen, making this app a little easier for some people to use in the field. The targeting graphic isn’t as detailed as GoSkyWatch’s but proves very effective nonetheless. The overall display is every bit as stunning as Star Walk and the 3D animations of the planets are superb. Whereas Star Walk’s 3D depictions of the planets and major stars show up in the info panel, in Redshift the planets are actually represented in 3D within the main viewer. Tap on Tools > Take 3D Flight, then choose an object to zoom into. The Grand Tour option is well worth sitting through and is just the thing for putting your planetary observing into context. The representations of nebulae are also superior in Redshift and despite Star Walk getting all the popular mass media attention when it comes to good-looking stargazing apps, this app is the better choice to use alongside telescopic observing, enabling you to check what you’re actually seeing with a bit more confidence. The red screen night time mode is practically identical to Star Walk’s. In terms of the number of observable objects it’s right up there with the very best iOS astronomy apps but it doesn’t track satellites or other man-made objects such as the International Space Station.

Luminos – Astronomy for iOS

Can Luminos be regarded as the finest planetarium app of them all?

The amazing level of detail is easily demonstrated by zooming into a planet or nebula. In Star Walk you get a thumbnail size, in Redshift a 3D object if it’s a planet, but here you get a stunning hi-res image, and in the case of the Moon you’ll see a real-time representation of the lignt being cast onto its surface. What about 3D? Well, that’s covered too, but in a different way to Redshift. Whilst you zoom into to see major objects as 2D you can then tap the object to bring up the detail pane and then choose ‘View from space’. You can then zoom in or out and rotate the object in 3D. In the case of planets you can also choose ‘Land on surface’, which will suddenly transport you to the surface of another world where you can look back at Earth! If all that wasn’t amazing enough you can view stars from Earth with the terrain for your location mapped out in front of you, showing the best viewing spots.

SpaceMap

Take a look at the bigger picturewith this awe inspiring visual explorer

There are a few 3D solar system tools on the App Store and whilst they don’t map the stars from Earth’s perspective, like planetarium apps do, they provide you with a realistic orrery. As with other digital orreries, like the excellent Solar Walk, the planets are set at a reduced distance from each other around the Sun to make navigation easier. It shows you real-time positions of the planets and you can choose to move forward or back in time. A  simple pinch in or out changes your view of the Solar System and you can rotate the entire orrery by dragging around. We particularly like the the ability to zoom quickly in or out via a scrollbar on the right of the screen. This has set distances in Astronomical Units, or AU (the mean distance between the Sun and Earth being 1 AU). At important markers, the names of obejcts are placed next to their distances on the scrollbar. A fantastic addition to your astronomy arsenal.

Star Atlas

Sometimes an old-fashioned star map is useful to have in your pocket

here’s no doubting the visual glory of augmented reality planetarium apps. Yet the level of detail found in flat maps is still useful for regular star spotters. Here you’ll find maps recreated to fit on an iPhone screen complete with Greek lettering for the Bayer numbers in a constellation (the major stars decreasing in order of visual magnitude) and the Flamsteed numbering system for the minor stars. There’s no  wizardry here and it doesn’t have the impact of something like Luminos, but it’s a tiny free install that proves to be just the thing as a backup tool.

The app is divided up into 18 scrollable maps and you can search by constellation or object type. Once again this app includes a night vision mode which stops your iPhone affecting your eye’s adaptation to the dark, but it’s only applied to the menus and not the maps which is a shame.

Observer Pro – Astronomy Planner

Make more of your stargazing with this companion app which helps you plan out a decent night’s viewing

So far we’ve concentrated on planetarium apps, but there’s a lot more to iOS astronomy. This app is a must if you stargaze with a telescope, helping you get set up in the right place by enabling you to work out where a star, planet or nebula will appear above the horizon.

A 24-hour viewing chart shows you your current time and where the object you’re interested in will rise and set. All graphs are colour-coded. For the ‘simplified’ chart, green displays the hours in the sky for best viewing, and the thickness of the bar represents at what distance the object will be straight overhead from your position (the zenith). There’s also standard monthly and yearly visibility bar charts which show you optimal viewing times.

The best features of the ‘standard’ visibility chart are the overlays of a red line for object altitude and a green line for object visibility based on your location. If you tap on the default black and white image of the object you’re interesting, like the Orion nebula for example, a sky map shows an arc of its progress over the day, going green when and where it’s best to view. All your favourite objects can be saved in a handy observing list to make things easier on another night.

Moon Globe HD

If Patrick Moore owns an iPhone or iPad, he’s sure to have this

To aid your lunar observations this app is just the thing for pinning down that particular peak or crater you’ve been studying. The Moon is beautifully rendered using the best satellite data and realistic lighting has been applied to make the separate images fit together seamlessly. It’s all in real-time too. As you move forward or back in time you can also see how the phases of the moon change on the map. It’s  fully interactive so you can rotate the Moon and pinch to zoom, with a handy tag cloud that floats just above the surface, labeling terrain features and spacecraft landing areas. The app also shows you where the Moon and Sun are in the sky with its sky compass. Once again a night viewing mode can be used. Resolution has been updated for the new iPad’s Retina display and as a universal app for just 69p it’s a must for lunar observers.

NASA App HD

Discover more about the universe you see through your telescope

This iPad only app lets you explore the Solar System as well as see some spectacular NASA pictures and videos. If you’re fascinated with space science and not just star spotting there’s a lot to like here. The app provides you with thousands of images from NASA IOTD, APOD and NASAImages.org, NASA videos, live streaming of NASA TV, current NASA mission information, launch information and countdown  clocks, as well as satellite tracking info and passes of the International Space Station. We can’t knock the vast amount of facts and figures from the world’s biggest space agency, but the actual page layouts are sloppy with images not well placed against some of the text. Things are better in the main menus for news, images and videos however. The ‘browse all’ mode for images is particularly useful for skimming through content quickly.

Space Images

The very latest NASA images in an easy to browse

Whilst much of the content here can be found elsewhere (including NASA App HD), it has a great menu design and more images to feast over. The app uses a category-selection tool to help keep images sorted sensibly and is just the thing if you have an obsession with a particular planet. Just tap on Saturn for example to only see images of that planet and its moons. You can rate each image and add to your favourites list for later. You can of course read more information about each picture but oddly this ‘More detail’ button has been placed two taps away from the image.

A selection images are available in 3D too if you have a pair of old red and blue glasses. Then there’s a few videos too. Watch footage compiled by active NASA spacecraft and watch movies about astronomy and various space missions undertaken in the past.