This week sees the appearance of one of the years best meteor showers, the Geminids, this Thursday evening. But before the Geminids peak, there is a small chance that meteors from Jupiter-family comet 46P/Wirtanen may be visible over the next few nights. Note, we have never (at least not definitely) observed meteors from Wirtanen. But computer simulations of the trajectories of dust released by the comet suggest that the Earth may encounter dust from its 1927, 1934, 1941 and 1947 returns. It is uncertain if any meteors will be seen but as always, we’ll never know unless we look.
For those who’d rather wait for a more certain shower, the Geminids on Thu/Fri night will definitely put on a show. I’ll post more on that shower later in the week.
In the meantime, the excerpt below is from Bob Lunsford’s Meteor Activity Outlook for this week:
Meteors from comet 46P\Wirtanen? There is the possibility that we may be able to see meteor activity from comet 46P\Wirtanen as the Earth passes through several filaments of material produced when the comet passed through perihelion during the first half of the 20th century. This is strictly an evening display as any meteors from this source would have a radiant of 23:48 (357) +04. This position lies in western Pisces, just east of the circle of faint stars known as the “Circlet”. This area of the sky is best seen as it becomes dark as it culminates between 1800 and 1900 (6pm and 7pm) local standard time. The first of these encounters is with the material shed in 1947. The expected peak is at 06:21 Universal Time (UT) on December 11th. This corresponds to 22:21 (10:21pm) PST and 23:21 (11:21pm) MST on Monday evening December 10th. The radiant is too low for any activity to be seen in the eastern half of North America. The second encounter is material from 1941. This peak is expected to occur at 10:20 UT on December 12th. This is too late for North America but observers in Hawaii may be able to see some of this activity. The third encounter is produced from the 1934 return. This peak is expected to occur at 12:30 UT on December 13th. This timing favors the western Pacific area. The last possible encounter is produced by the 1927 return. This peak is expected to occur at 00:02 UT on December 14th. This corresponds to 19:02 (7:02pm) EST and 18:02 (6:02pm) CST on the evening of December 13th. This timing favors the eastern half of North America. If any meteors are produced from this source, they would be extremely slow.