Before sunrise tomorrow – April 27, 2014 – most of the world will see Venus rising first, then a very slim crescent moon close to the time of sunrise. Both will ascend over the eastern horizon shortly before the sun comes up. Astronomers call this very thin crescent moon an old moon. Soon this waning crescent will reach the new moon phase. It’ll pass between the Earth and sun, causing a partial solar eclipse visible from Australia on the afternoon of April 29. Afterwards, a new lunar cycle will begin, and in early May the moon will be back in the evening sky, visible shortly after sunset each evening as a waxing crescent.
As seen from mid-northern latitudes, Venus is rising in the east roughly one-and-one-half hours before sunrise on April 27. At more northerly latitudes, Venus rises closer to sunrise; at more southerly latitudes, Venus rises farther from sunrise. At temperate latitudes in the Southern Hemisphere, for instance, Venus rises well over three hours before sunrise.
All other things being equal, it’ll be more difficult to catch the old lunar crescent in North America than at similar latitudes in Europe and Asia. At northerly latitudes anywhere, however, an unobstructed eastern horizon will be to your advantage for catching the old moon by the horizon. At mid-northern latitudes in North America, the moon rises about one hour before the sun on April 27. Binoculars might come in handy!
The old moon will be easier to see from the Southern Hemisphere in the coming mornings. Southerly latitudes might catch the older, thinner lunar crescent before sunrise on April 28.
Bottom line: If you’re up early on April 27, look first for the dazzling planet Venus, the third-brightest celestial body to light up the heavens, after the sun and moon. Then see if you can spot the old moon beneath Venus and close to the horizon with either the unaided eye or binoculars!