Archive for August 2nd, 2018

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A planetary observing run on Mount Baldy

August 2, 2018

Last night I went up to Cow Canyon Saddle with some fellow PVAA members and other friends, for an informal star party. Venus, Jupiter, Saturn, and Mars are nicely lined up along the ecliptic right now, so we went to take a look.

I was rolling with London’s XT4.5 dob and my Apex 127 Mak. I hadn’t gotten the Apex out in a little over a year, and it was nice to confirm that it’s still in fighting trim.

Me, not so much. It was my first session with a scope – any scope – out in months, and I was a little scattered. I had to rifle through three bags to find my good diagonal, and it took three attempts to get out of the house with both my phone and my headlamp. The rustiness even extended to the sky. Normally I can get most of the good stuff using memory and dead reckoning, but I had to haul out an atlas to remember how to get to M81/M82 and M11. Sad!

I got up to Cow Canyon Saddle a little after sunset. Amanda and Ron Spencer and their kids were already set up, checking out Jupiter with their 90mm refractor. Ludd Trozpek was there, too, with a 10-inch dob. My friends and WesternU colleagues Thierra Nalley and Jeremiah Scott arrived a few minutes later.

Thierra, Jeremiah, and I started in Venus, which is in a half-full phase right now. We quickly moved on to Jupiter and then Saturn. Mars hadn’t cleared the mountains to the east so we spent some time running up the magnification on Saturn. The seeing was phenomenal. We put the 8.8mm ES82 in the Apex 127 for 175x and Saturn looked like it was nailed to the wall. We put in the 5mm Meade 100-degree and at 308x the seeing was visible, not as the usual small-scale shimmers, but as an occasional wave of distortion washing over the whole field of view, as if we were viewing Saturn through a thin film of water with a low ripple now and then. In my experience, nights on which I can push past 300x are few and far between, so we got pretty darned lucky.

Enough about the eyepieces and the conditions. The planets looked unreal. Even at low power, Saturn’s Cassini Division was easy and crisp, as if it had been punched out of the disc of the rings with a metal press. At higher power, the shadow of the rings on the planet and the shadow of the planet on the rings were equally stark. And the planet itself was striped with pastel bands of salmon and cream. We had no problem holding any of these details in direct vision. As always, it was a kick in the brainpan to be reminded that while I’ve been going about my little business on this little planet, Saturn has been doing its own thing out there, 800 million miles away: regal, immanent, undeniable. We caught Rhea and Titan, too, but failed to spot the other moons.

Jupiter was only slightly overshadowed by its smaller sibling. The King of Planets was wrapped in dozens of belts and zones, down to the limit of vision, with the four Galilean moons neatly arrayed to either side.

Of course, we had gone up in large part to look at Mars, and see if we could detect any details through the nearly-global dust storm. When Mars cleared the mountains to the east, it was instantly the brightest thing in the sky. Even Jupiter looked wan compared to the red planet. I think every scope on the mountain was aimed at Mars within the first minute. The seeing may have been good up high, but Mars was fairly boiling in the near-horizon turbulence. Still, we could see the north polar cap immediately.

We decided to let Mars climb up out of the murk, so we switched to the deeper sky for a while. Lyra was almost at the zenith and Epsilon Lyrae was an easy split at 175x in the Apex 127. We spent some time with the Ring Nebula while we were in that neighborhood, then swung north to catch M81 and M82 before they got too low. Then it was back to the band of the Milky Way to pick up M11, the Wild Duck Cluster (after the aforementioned faffing about) and Albireo.

We went back to Mars and the view in clear air was vastly improved. The north polar cap was steady, and we caught fleeting hints of detail elsewhere on the planet. I don’t think that was all imagination – the most recent Hubble images show some of the dark features in the southern hemisphere starting to emerge through the dust. We had fun, both with the observing and with teasing each other about Percival Lowell, canals, and Tharks.

Jeremiah had been keeping an eye on Cassiopeia as it rose in the northwest, and I was casting frequent looks in that direction as well. A little after 10:00 the Double Cluster finally cleared the local horizon and we got a nice look at 48x in the Apex 127 (as low as that scope goes, using the trusty 32mm Plossl). Our final object was the heart asterism around Sadr at the center of Cygnus, which I wrote about for the Binocular Highlight column in the July issue of Sky & Tel.

The Spencers had departed before we looked at the Double Cluster, and Thierra and Jeremiah left after Sadr. Ludd and I finished the session with a few minutes of binocular observing. He had along a recent acquisition: a WWII-vintage Sard 6×42 with a true field of 11.9 degrees. It’s a legendary instrument that lives up to the legend. The first thing you notice when you pick them up is that they’re heavy – there’s a lot of glass in there. That’s in part because the prisms are huge. Unlike some modern binos that skimp on prisms, the Sards have prisms that are if anything maybe a little oversized. The eye lenses are also immense. It’s not just a lot of glass, it’s good glass, as I could tell as soon as I looked through them. It’s not sharp to the edge – stars take on interesting shapes in the outer 25% or so of the field – but it is impressively sharp over a huge true field, with excellent clarity. It was an interesting experience, looking at all of the constellation Lyra at one time. Cassiopeia almost fits – you can see all but one of the stars at either end of the W/3/M. Ludd reports that under darker skies, the Sards are a wonderful tool for scanning the Milky Way. They’ve re-fired my occasional interest in low-power, super-wide-angle binos. If anything comes of that, you’ll hear it here first.

So, all in all a fantastic observing session, with some of the best views of Jupiter and Saturn that I’ve ever had. I should do this more often.