Meteors and Comets

The past few nights have been interesting. On the evening of December 13–14 was the peak of the Geminid meteor shower. This year the expected peak was around 100–120 meteors per hour and various meteor counts appear to confirm that number.

At the same time, Comet 46P/Wirtanen has been getting a lot of attention. On December 16 it made its closest approach to Earth—only 11.5 million km away. That’s about 30 lunar distances for reference.

From SpaceWeather.com: “Although the comet is very close to Earth, it is not very bright. 46P/Wirtanen is a relatively small comet and, thus, barely visible to the unaided eye despite its proximity. It is nevertheless an easy target for digital cameras. Even a short exposure reveals the comet’s spherical form and emerald green hue.”

During the late evening of December 13, I traveled to Wupatki National Monument because of its dark skies. I shot a sequence of photos—each of 30 seconds duration—of the night sky hoping to catch a few meteors. One bright meteor blazed across the sky and I was able to catch part of it before it moved out of the frame of the camera. At the same time, the crescent Moon was setting in the west and gently illuminating Wukoki Pueblo. At the very top center of the photograph is Comet 46P/Wirtanen.

Geminid meteor, Comet 46P/Wirtanen and Wukoki Pueblo.
Geminid meteor, Comet 46P/Wirtanen and Wukoki Pueblo.

After about 1/2 hour of shooting meteors, I shot longer exposures of the comet. On this night, the comet formed a triangle with the Pleiades and Hyades star clusters. The image shown here is from ten 60-second images stacked using Deep Sky Stacker (DSS) and post-processed using  rnc-color-stretch.

Comet 46P/Wirtanen with the Pleiades and Hyades star clusters.
Comet 46P/Wirtanen with the Pleiades and Hyades star clusters.

A few nights later, the comet had moved so that it was between the Pleiades and Hyades clusters. Again, I shot a sequence of 60-second exposures totaling about one hour in duration—this time from the Mormon Lake overlook. The motion of the comet is quite apparent in this sequence of images. The first image shows the motion of the comet against the stars; the second is a time-lapse movie of the same sequence.

The motion of Comet 46P/Wirtanen is seen as a short streak in this one-hour composite image.
The motion of Comet 46P/Wirtanen is seen as a short streak in this one-hour composite image.

Time lapse movie showing the motion of Comet 46P/Wirtanen during a period of one hour.

Comet 46P/Wirtanen is now moving farther from Earth and will slowly dim in brightness but it will remain visible through binoculors, telescopes, and with digital cameras for many weeks or more. There is still plenty of time to see the comet if you haven’t already.

Geminid meteor shower

The Geminid meteor shower peaked on the evening of 13 December and skies were incredibly clear all that day. Just as darkness was arriving, clouds were starting to approach from the north. Would I be able to get some photos of a few meteors in the early evening before the clouds arrived?

The clouds moved in about 45 minutes after I started shooting and remained through most of the evening. If I had been located a bit farther to the west or south, clouds might not have been a problem, as can be seen in this Infra-red satellite image.

Infrared satellite image from GOES-West at 0600 UTC (11 P.M. MST).
Infrared satellite image from GOES-West at 0600 UTC (11 P.M. MST).

Now, that’s just bad luck on my part.

I pointed the camera at the radiant and used my iOptron Skytracker to keep the camera pointed at the radiant as it rose higher in the sky during the evening. I was then able to combine several images showing a handful of meteors originating from the constellation Gemini.

The brilliant meteor in the upper right corner occurred while the sky was partly cloudy and, as a result, the beginning of the track was obscured by clouds. I didn’t see this bright flash as I was looking in another direction but it was so brilliant that it lit up the sky and landscape for a second or two.

Composite image showing several Geminid meteors.
Composite image showing several Geminid meteors.

The small number of meteors captured by the camera doesn’t tell the whole story. There were many more—some brilliant and many long-tracked—that streaked across the sky that evening. We had a wonderful time looking up at the sky.