Taking pictures of stars and deep sky objects with an iPhone would not have been something I thought would have worked, but as Apple hardware improves with better low light camera performance, apps are there to exploit it and push the envelope.
Several users of NightCap Pro, an app designed for night and low light photography, are getting some impressive results.
Star trail shots are looking pretty good, and we're seeing meteor captures, and even shots of the International Space Station as it orbits the earth like the one at the top of this post. One amateur astronomer grabbed a decent shot of M42, the Orion Nebula, by attaching his iPhone to a telescope.
The twin enemies of low light photography are grain and noise, and NightCap Pro does a good job of reducing the noise, leaving your faint subject visible. None of these photos are going to rival the Hubble Space Telescope output, but it's pretty amazing what an iPhone can do with the right software.
Many iPhone owners have had some luck in the past taking photos of the moon through a telescope, but the moon is bright and doesn't put the iPhone camera to much of a test.
NightCap Pro has a special 50 percent discount offer currently, making the app only US$0.99. The app requires iOS 7 or later, it's optimized for the iPhone 5 and 6 series, and it's universal for iPads.