Mobile stargazing: Binocular astronomy tips and targets for summer 2017

Summer is a perfect time to explore the night sky with the wide-field views that binoculars provide. Whether you are using regular binoculars or the image-stabilized type shown here, sweeping your view across the Milky Way as it rises from the southern horizon will reveal many nebulas and star clusters. Your mobile astronomy app will help you identify the objects. (Credit: SkySafari App and Canon USA)

In the Oct. 21, 2016, edition of Mobile Astronomy, we examined how to use binoculars for astronomy, explained how they work and what to shop for, and suggested some night-sky objects to look at. This time, we'll cover some tips for making binoculars work better for you, highlight a type of binoculars that helps with unsteady hands and share a variety of targets to look for this summer.

Using binoculars for astronomy

Binoculars consist simply of a matched pair of small telescopes precisely mounted together to deliver a stereo image to your two eyes. The lenses at the front are called objectives. As with any optical device, the larger the area of those lenses, the more light they collect and concentrate into your pupils.

The small lenses you look into are called eyepieces or oculars, and they do the job of magnifying what you see. In binocular specification numbers, such as 7 x 50, the second number is the diameter of the objective lenses in millimeters and the "7x" means the binoculars will magnify by seven times.