One of the best ways to check whether summer has arrived is to look at the eastern sky after it gets dark. Climbing above the horizon at this time of year is a group of stars called the Summer Triangle, a vast but simple arrangement of three very bright but very different stars.
Not only does its arrival in the night sky signal the beginning of summer in the Northern Hemisphere and winter in the Southern Hemisphere (where it's known as the Winter Triangle), but this triangle marks where to look for the Milky Way if you are under dark skies this season.
