Dec. 16, Comet 46P/Wirtanen
On Dec. 16, Comet 46P/Wirtanen will make its nearest approach to the sun, and it will be visible just after dusk. The periodic comet, which revolves the sun once every 5.4 years, was discovered in 1948. Its last near approach to Earth occurred in 2013, when it was 564 million miles (907 million kilometers) from Earth. While it was lees than amazing last time, this year Wirtanen will come much closer! When it swings by again on Dec. 16, Comet 46P will be only 7.3 million miles (11.7 million km) away creating much better conditions for the observer .
Comet 46P/Wirtanen is a tricky object and tends to be visible only with a good telescope or a good pair of binoculars. But this year it will be exceptionally bright. It can reach up to a third magnitude, which is similar to the faintest star in the Big Dipper. Look toward the winter constellations of Taurus the bull, near the Pleiades and Hyades star clusters for the comet on Dec. 16