Lifeboat Foundation

If you have clear skies and are willing to brave the chilly temperatures, you might want to head to a dark site and look for a passing visitor.

Comet 46P/Wirtanen, first discovered in 1948, will have its closest encounter with Earth on Dec.16. But it’s already visible in the sky.

While this is the brightest comet of the year and the 10th closest comet in modern times, don’t expect one with a well-defined tail, a hallmark of comets.