Go out soon to see Jupiter and Saturn

Saturday Shot with 120mm APO refractor and ZWO 221 planetary camera.

Here's an image I shot Saturday night of the conjunction of Jupiter and Saturn, the closest they have been in 800 years. Because Jupiter and Saturn are two of the most interesting telescopic objects (particular to sky newbies) the chance to see them both in the same view is remarkable, and short of a total eclipse, is one of the most impressive telescope sights. The good news is you can see it with almost any telescope -- even cheap ones -- and from inside the city. You just need clear skies and a view to the SW at dusk, about 40 minutes after sunset. (The longer you wait the darker it gets but the lower they sink in the sky.)

The next night I shot this one I like even better, with an 8" SCT and a Sony A7RII.

Sunday shot (closest approach) with Meade 8" SCT reflector and Sony A7RII mirrorless camera. 4 moons plus small star HIP 99314 perfectly in line with them.

You do need a telescope. To the eye you will just see some pretty points together, and you will barely see the moons of Jupiter and the rings in good binoculars - worth it, but they get in binocular range every 20 years.

Here you see Jupiter with some bands, Saturn with well tilted rings, and the 4 brightest moons of Jupiter all lined up to the side. Sunday night in North America you will see all 4 again. Monday night is slightly closer but Ganymede will be hidden behind Jupiter. Not visible is Titan, the giant moon of Saturn, which is too dim.

This is an HDR shot combining three images, and each of the 3 images is the result of stacking hundreds of ordinary images with modern digital techniques. A regular camera can't take a photo like this. Jupiter is much brighter than its moons or Saturn, so any normal photo won't show all 3. However, this is what the human eye sees because the eye has the range to see dim and bright together that a camera does not.

In addition, digital stacking techniques make the image much better. For this you take 1,000 or more images -- a movie of sorts -- and software then picks out the best ones, then combines them together in a way that also gets rid of sensor noise. When you look at things in the sky, you find they wobble and move from fuzzy to sharp. Your eye will catch and remember that short instant when things were sharp, but with a camera we just pick out those brief moments to get our good image.

The moons, in order from Jupiter are Io, Europa, Ganymede and Callisto in the Saturday shot. Ganymede and Titan (not visible) are the two largest moons in the system, bigger than our moon.

The reason this view is so impressive is the scale. Space is really big. I mean, you think it's a long way to the chemists, but... As such, in reality the common scene in Science Fiction movies where you see pairs or other groupings of planets just aren't real. But tonight, it's real. There's Jupiter, 11 times as wide as the Earth, half a billion miles away, and Saturn -- even with rings even wider but smaller to the eye because it's a billion miles away -- all right in the eyepiece of your telescope. Enjoy.

How to see it

Go out just after sunset. Jupiter and Saturn are the two brightest things in the sky other than the moon. Look to the southwest. You do need to find somewhere that doesn't have tall buildings are trees in that direction. You will see them before it gets dark. The longer you wait the darker it gets (good) and the lower they get (bad.) Probably 40 minutes after sunset is your best shot, or less if you don't have a more open horizon.

They will be, at that time, around 15 degrees above the horizon. Hold your fist out at arm's length, that's about 10 degrees wide. So one and a half fists (twisted vertical.)

Get a telescope or very good binoculars. With the telescope, start with your wide field (long) eyepiece and find it, then switch to a smaller one.

Starting tonight, go out the first night it's clear at sunset. Sunday and Monday night are best, but it will still fit in most telescope views all the way to Christmas.

How to photograph like this

You can do it with many DSLR cameras if you don't have a dedicated astrophotography camera. You can record a movie (use as little compression as you can) or even just use rapid fire shooting in raw. To save space, tell your camera to crop to the smallest image size that the planets fit in, which will probably be just 2 megapixels or so. For Canon cameras there is software that can suck an uncompressed movie out of the camera over USB at a fast rate. Might be available for Nikon, not yet for Sony unless that's changed.

Then feed the series of images or movie into a stacking program. Two that are good for planets are Registax 6.1 which is very old but works and does wavelet sharpening, and Autostakkert which is newer but does not do sharpening. Both will run under wine or linux/mac if you don't have Windows.

For HDR, I ended up doing this by hand, the automatic HDR programs don't like these images, though maybe I have to play around. The images are simple enough it's easy to do it by hand, may even look better.

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