WWe start December with one of the best chances to see Mercury this year, at least for the Northern Hemisphere. The elusive inner planet never strays very far from the sun, but this week it reaches the configuration known as greatest western elongation.
This means that from our vantage point on Earth, the planet appears as far from the sun as possible. It will appear in the pre-dawn twilight sky. For observers in mid-northern latitudes, the geometry is favorable and therefore the best views are possible 30 to 60 minutes before sunrise.
The map shows the view looking south-east from London at 0700 GMT on December 7. Although still low in the sky, Mercury will be undeniably bright. As the darkness of night gives way to the brightness of day, the stars will disappear one by one. Mercury will be the last to succumb.
The planet will only be marginally visible from the southern hemisphere. But for those up for a challenge, a clear eastern horizon will be essential for getting a glimpse. Binoculars might help reveal the planet, but don’t use binoculars at sunrise. Catching even a glimpse of the sun can cause vision damage.
