Comet 46P Wirtanen may not look like much right now but it is already developing a tail and is expected to become visually visible and the brightest comet for the year. This short period comet come closest to the sun every 5.4 years and will be at perihelion December 13. What makes this closest approach favorable is that on perihelion it will come very close to the Earth at 0.078 AU or just five lunar distances.