The waning moon and Mars rise in tandem over Lake Superior from Duluth, Minn. last night. Bob King
The waning moon and Mars rise in tandem over Lake Superior from Duluth, Minn. last night. Bob King

We had just enough breaks in the clouds to enjoy the Mars-moon conjunction last night. I loved seeing the color contrast between the two celestial bodies, something you can really only appreciate when they're close together. The moon will be near the Red Planet again tonight but about a fist to its left or east.

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Find the moon, and focus it sharply in binoculars. Place it near the bottom of the field of view and look near the top for two similarly bright stars. The bottom "star" is the planet Uranus. Although I made the map for 11 p.m. Uranus will still be rather low in the east at that hour. If you need more altitude because of trees or buildings in the way you can also wait until midnight when it will be better placed.Stellarium with additions by the author
Find the moon, and focus it sharply in binoculars. Place it near the bottom of the field of view and look near the top for two similarly bright stars. The bottom "star" is the planet Uranus. Although I made the map for 11 p.m. Uranus will still be rather low in the east at that hour. If you need more altitude because of trees or buildings in the way you can also wait until midnight when it will be better placed.Stellarium with additions by the author

Did you know that the moon will be in conjunction with another planet tonight? It passes just 3.5 below distant Uranus, which is 1.8 billion miles (2.9 billion km) or 38 times farther from the Earth than Mars. I'm certain that a small telescope will show the 7th planet with ease even with the bright moon nearby, but I wonder if we might also see it in binoculars. In a moonless sky, Uranus is easy prey for a 7x35 or 10x50 glass, but lunar glare makes tonight's conjunction an excellent observing challenge. Want to give it a try? Use the chart to track down Uranus, located to the north of the moon in the same binocular field of view.

I properly exposed the moon here at 11 p.m. Sept. 5 when they were closest, but notice that Mars appears pretty insignificant — not how it looked to the eye which compensates for light of different intensities much better than a camera. Details: 600mm focal length, ISO 800, 1/500th second at f/7. Bob King
I properly exposed the moon here at 11 p.m. Sept. 5 when they were closest, but notice that Mars appears pretty insignificant — not how it looked to the eye which compensates for light of different intensities much better than a camera. Details: 600mm focal length, ISO 800, 1/500th second at f/7. Bob King

Like some of you I like to photograph conjunctions of the moon and planets, but as you've probably discovered already, it's not always easy. The biggest problem is the difference in brightness between the moon and the planet. Twilight tempers the overbright moon and makes it easier to get a photo showing both objects. But if they're only visible in a dark sky — as the moon and Mars were last night — it's impossible to make Mars appear bright the way it does to your eye without overexposing the moon. This is especially true when the moon's phase is half or more.

One way to tone down the moon is to photograph it near the horizon where the denser air acts as a filter. I tried that with modest success. Or you can expose the moon properly and accept the fact that Mars will appear very tiny and not particularly bright as depicted in the photo above. But if I'm lucky and clouds are about I make them my friends.No surprise, clouds heavily filter moonlight. If you carefully monitor their progress across the moon's face you can catch moments when the moon is mostly covered or faintly visible through them while the planet (Mars) pops into bright view in gaps between the clouds.

Clouds can both filter the moon's intense light and also provide a dramatic foreground as they did last night during the conjunction. I waited for thicker clouds to partially cover the moon at the same time Mars appeared in a relatively clear spot. Parts of the moon are still too bright, but the clouds certainly helped!Bob King
Clouds can both filter the moon's intense light and also provide a dramatic foreground as they did last night during the conjunction. I waited for thicker clouds to partially cover the moon at the same time Mars appeared in a relatively clear spot. Parts of the moon are still too bright, but the clouds certainly helped!Bob King

As you watch the movement of the clouds you can anticipate when a planet-gap coincides with a masked moon and take photos like crazy to seize the moment. Of course we don't always have clouds to lend a hand. That's where Photoshop and other digital imaging tools are useful. I use them to even-out differences in the brightness values of the moon, clouds, planets and horizon as best I can. My goal is always the same — to make the final image look as close as possible to the way it appeared to the eye.

If you take a series of photos of a close conjunction over an hour or two you'll easily capture the moon's movement as Piqui Daz did during last night's event. Diz used an inexpensive cellphone and one barrel of a pair of binoculars to take these photos.
If you take a series of photos of a close conjunction over an hour or two you'll easily capture the moon's movement as Piqui Daz did during last night's event. Diz used an inexpensive cellphone and one barrel of a pair of binoculars to take these photos.