22° halo – The Amazing Sky

Cloud hid Comet Catalina but added a halo around the waning Moon, intersected by the line of the ecliptic.

I’m in Arizona, just inside the state line with New Mexico, on a quest to shoot Comet Catalina at dawn. Clouds prevented any view of the faint comet this morning but provided a fine consolation prize.

The waning crescent Moon was surrounded by an ice crystal halo, a rare sight around a thin Moon. The Moon was between Mars and Jupiter, heading toward a conjunction with Venus, below, on December 7.

The line of Venus, Mars, the Moon, and Jupiter, plus the stars Spica and Regulus defined the line of the ecliptic beautifully in the pre-dawn sky.

A classic 22° ice crystal halo around the waning crescent Moon, here overexposed, with the Moon between Jupiter and Mars in the morning sky on December 5, 2015. Seeing a halo around a crescent Moon is somewhat rare as they usually require the brighter light of the Full Moon. Venus is the brightest object at bottom closest to the horizon. The three planets, along with the stars Spica (above Venus) and Regulus (at top of frame) define the line of the ecliptic here in the dawn late autumn / early winter sky. I captured this scene from southeast Arizona near the Arizona Sky Village at Portal. This is a stack of 4 exposures from long to short (8s to 1/2s) to encompass the great range in brightness and not overexpose the crescent Moon too much. Images were layered in Photoshop and masked with luminosity masks. Automatic HDR techniques did not work well as the shortest image was too dark for ACR to find content to register in Merge ot HDR, and in Photoshop the HDR Pro module left visible edge artifacts. The camera was on the iOptron Sky Tracker to follow the sky and register the sky for all the exposures, thus the slightly blurred ground. Taken with the Canon 6D and 15mm full-frame fish-eye lens. — This is a stack of 4 exposures from long to short (8s to 1/2s) to encompass the great range in brightness and not overexpose the crescent Moon too much. Images were layered in Photoshop and masked with luminosity masks. Automatic HDR techniques did not work well as the shortest image was too dark for ACR to find content to register in Merge ot HDR, and in Photoshop the HDR Pro module left visible edge artifacts.
The camera was on the iOptron Sky Tracker to follow the sky and register the sky for all the exposures, thus the slightly blurred ground. Taken with the Canon 6D and 15mm full-frame fish-eye lens.

It was a show of circles and lines, real and imagined, in the morning sky.

With luck, clouds will clear to reveal Comet Catalina, which is likely fainter and less spectacular than hoped. But such is the way of comets. Regardless of what the comet does, it is a good time to be in the desert southwest, typing this blog on a sunny front porch under blue desert skies.

An ice crystal halo surrounds the Moon while a jet contrail crosses the sky.

On our last nights earlier this week at the Churchill Northern Studies Centre we had a bright gibbous Moon in our sky (as did everyone in the world!). We also had high-altitude clouds filled with ice crystals, the source of the “ring around the Moon” effect. This is a lunar halo, created by moonlight shining through six-sided ice crystals. This halo exhibits rainbow-like colours as well.

But this night, conditions were also ideal for seeing the contrails from jets flying overhead on polar routes from Europe to North America. In the main image above, you can see the jet departing to the west at lower right. Its high-altitude contrail is casting a dark shadow onto the lower cloud deck.

This view, taken earlier in the evening shows a more pronounced lunar halo with a horizon-to-horizon contrail shooting straight across the Moon and also casting a shadow.

I used an 8mm fish-eye lens to capture this 360° image of the entire sky. I was able to shoot this image in shirt-sleeve comfort through the rooftop plexiglas viewing dome at the Centre.

In this image, taken outside at -25° C, the sky is clearer but still contains enough ice crystal cloud to create a bright lunar halo. When I took this image on February 9 the Moon was to the right of bright star-like Jupiter, and in the middle of the winter stars and constellations, such as Orion just below the Moon.

Lunar haloes can be seen at any season. On any night with a nearly Full Moon embedded in high haze, look up!