July 14, 2018: My Local Dark Site Ain’t So Dark, Redux; and No-Detail Mars, Redux

The three longtime readers of this blog might recognize the title of this post; I wrote another post about the shortcomings of my local observing site just short of two years ago, right after I moved into my apartment in Glendale, a tiny little independent city completely surrounded by Denver.

Up until now, I’ve basically had three choices for observing “here” from my Aurora condo.  The first is off of my balcony, which has relatively open views to the east and south.  This is just fine for quick views of the moon and planets with the Mak; I did the same thing at my apartment in Glendale, too, last year.  But this is no good for setting up the C9.25 and getting some views of DSOs.  There’s way too much ambient lighting around here.  I inadvertently moved into the high-crime neighborhood of Aurora (oops!), and my condo association tries to make up for this by lighting this place up like a prison yard after a break.

The second option has been to go to a local park, Settler’s Park.  It’s about half a mile away, and that’s fine if I just want to throw the Mak over my shoulder and hoof it, like I used to do to get to Carl Schurz Park back in Manhattan.  But I don’t wanna do that anymore – I need to get my big bad boy, the C9.25, out and under some dark skies.  So, inevitably, I just drive over instead.  I keep most of my scope stuff in the car to make this as easy and quick as possible.  Fortunately for me, the local car thieves don’t seem to be too interested in eyepieces and lithium-ion batteries.

Settler’s Park ain’t awful, but it taint too good, neither.  If I go deep into the park, I can put the park lights (which are ALWAYS ON, all night) mostly behind me so that they don’t affect my dark adaptation.  There are clear views east and south, which is where all the good stuff is anyway.  But there are still lights out that way – both from additional people living east of me, and because I’m overlooking Buckley Air Force Base.  On the other hand, west is a mess, and even overhead is not very good.  I’m looking back into both the local lights from the houses on the west side of the park, and looking back into the huge Denver metro light dome.

The third option, of course, is to go all the way out to the DAS Edmund G Kline Dark Site.  As you might imagine, that’s quite an investment in time, too.  Just over an hour each way, plus all the gas, and then not only do you gotta bring all the scope stuff, but you gotta bring water and snacks, too, and dress for cooler weather to be out on the plains all night.  Of course, those trips have not always been all that successful of late, so the time investment doesn’t pay off a lot of the time, whether due to incessant wind or insanely bad weather forecasts.

Obviously, the skies out 60 miles east of town are very nice.  Very nice indeed.  But when you’re going out there, you’re going out not just for an observing session, but for an OBSERVING SESSION.  If I just want to get out and observe for an hour or two, say a few days after the full moon, when the moon rises at 11 or Midnight, it’s definitely not worth it to travel 2 1/4 hours out to the dark site for that.  You go out to the dark site for 3 or 4 hours or more.  It’s a whole big to-do.  Mind you, when the conditions cooperate, it’s well worth it, of course.  But with the conditions not cooperating, it’s been more than a little annoying.

All this got me wondering – maybe there’s some local place, somewhere that isn’t quite as far, that’s better than Settler’s Park?  If I’m driving the 3 minutes there anyway, maybe there’s another park not too much further, say, 15 or so minutes away, that might be better?  I mean there’s no real difference between driving 3 minutes and 15.  I took the advice of Bruuuuuce, who told me that there’s a darkness on the edge of town.

I pored over Google Maps, finding a few parks towards the northeastern edge of town – Aurora Sports Park, Environmental Park, Triangle Park.  None of these were much good because they were either closed at night or had plenty of car lights going by very close to the park.  Saint Simeon Cemetery was out there, too, but cemeteries creep me out.  So that was a non-starter.

I found Great Plains Park a bit further south.  Talk about the edge of town – there’s nothing east for miles.  The Dark Site Finder map shows that it’s one zone darker out of fifteen – from dim white at home/Exposition Park to dark red.  Better, but one zone isn’t really gonna do much to the skies from Settler’s Park.  Plus, there are still the all-night park lights and lights from people’s homes nearby to deal with.

I just drove around the general area to see if I could find something better, when I stumbled upon the eastern end of Ohio Street.  It’s ranch country out there, no street lights, wide open, and the road ends in a nice round cul-de-sac – public property, so I could set up “in the road” without being on anybody’s property, and without worrying about getting run over.

But I was literally right in the street across from two houses at the end of the road there – very noticeable when no one comes down your street in the first place.  Not wanting to spook anyone, I introduced myself to the people there, gave them a look at Jupiter and a tour of the skies, and had a nice chat.  They told me about a really dark location they knew of just a couple of miles further down the road, kind of like this one – a bend in the road where the road widens out, and it’s easy to pull off to the side and set up on the road itself, but neither in traffic (which there wouldn’t be, anyway) or on private property.

I checked it out, and man, they weren’t kidding.  Just 11 easy miles east of my condo, and there were no people, no lights, no nothing.  Dark, like dark-site dark – no ambient light anywhere whatsoever.  (That location next to those ranchers’ homes, even though adjacent to a huge empty field on the east, still had streetlights a few hundred yards to the south and south east.)  I figured that this utter darkness will let me dark adapt even more and let me get that much deeper – at least on objects to the east and south, anyway.

Looking at the dark sky map, now I was three zones darker – right past red and into orange, the fifth zone, one-third of the way to utter darkness.  Just like at the dark site, I could see the light dome from Metro Denver to the west, except instead of it rising just 15 degrees above the horizon, here it was more like 50.  So, not much observing in the west, that’s for sure.  But otherwise, seems like it’s the place to be!

A coupla days ago, right after someone in my astroclub posted how great the observing conditions were, I drove out to this spot just after midnight.  The last time I was out there, the moon was up, but now we’re at new moon, so it was really nice and dark here.  The Milky Way was an arc right overhead.  Not bright or anything, but definitely there, from Sagittarius all the way to Cassiopeia.

Strangely, the sky seemed to get brighter as I observed, to just after 2am.  There were two bright white lights way off on the eastern horizon – like two farming combines getting some late night combining in or something.  Something mechanical/industrial going on, I dunno.

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But I didn’t let that stop me from getting a nice little observing session in.  The sky was clear and Greater Sagittarius, just about my favorite part of they sky, beckoned.  I toured all the Messiers down south, including some of my favorites, M11, the Wild Duck Cluster; M22, the great globular of Sagittarius; M17, the Omega/Swan Nebula; and most of the other familiar Messiers down that way.

Unfortunately, the nebulae weren’t so hot.  Yes, I could see the familiar “2” shape of the Swan Nebula, but the Trifid (M20), the Lagoon (M8), and the Eagle (M16) were pretty much still washed out – even with 9 1/4 inches of aperture.  That blows.  Basically, the entire point of coming out here to observe as opposed to staying in Settler’s Park was to see them.

I also looked at M57, the pretty little smoke ring that is the Ring Nebula, which I hadn’t seen for a while.  Then I made a comparison between the two great globulars of the sky, M13 and M22.  M22 came out on top.  More granulation, more stars that were visible on their own, apart from the glowing central core, just more aesthetically pleasing all around.  M13 has never really been a particular favorite of mine, because it’s got the word “Great” right in its name, and other globs, like it’s Herculean neighbor, M92, look better than it does, and they aren’t called “great”.  Unfair treatment of globs, I say!

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As you probably already know, Mars is approaching opposition on July 27, and it’s already very big and very bright.  Mars has these oppositions every 26 months; this one is the closest approach since 2003, and is the closest until 2035.  Mars will be 24 arc seconds across at the time of the opposition, far larger than its usual 5 or 6 arc seconds when it’s not approaching opposition.  Obviously, when the disc of Mars is so much larger than usual, the polar ice caps and surface albedo features are much, much easier to see.

As you probably also know, last month a global dust storm struck the entire planet.  I’ve read that as Mars makes its closest approach to the Sun (which just happens to be coincidental with its closest approach to the earth this year, but why this opposition is such a close one), the planet heats up, the winds get stronger with all the extra thermal energy, and these dust storms arise.  And when these storms happen, they persist for months at a time.  Bleah.

Dust storm covering everything on the right; what the actual surface of Mars would look like without the storm on the left.  Credit:  NASA.

So, with the opposition fast approaching, I had a nice long look at big, fat Mars.  It was bright; it was orange.  I was using the Baader Moon & SkyGlow filter in my C9.25 to enhance my view, boost contrast, and let me see something, anything.  And there was just a whole lotta nuthin’ on Mars.  No-detail Mars, redux.  The planet was an absolute blank.  Darned dust storm. Grrrrr.

Other than a featureless orange ball, all I could see was the red, white, and blue atmospheric dispersion due to Mars being so low in the atmosphere.  I discussed this phenomenon two years ago, at the last opposition of Mars.  Atmospheric dispersion works like the achromatic objective in a refractor – the thick atmosphere breaks up the light like a prism.

Unfortunately, the vibration/wobbling problem that reared its ugly head with my Orion Sirius Pro AZ/EQ-G last month at the RMSS was still present.  There was a relatively steady breeze out on the eastern plains, approaching 10mph.  As I observed to the south, the scope was perpendicular to the direction of the wind, so the scope literally wiggled back and forth, causing Mars to bounce across the field of view.  I estimated that it was moving about 10-15 arc minutes, back and forth, which made it almost impossible to really observe.  And the mount just shouldn’t do that.  More on the mount problem in a future post.

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Speaking of future posts, some readers with elephantine-like memories will remember that I was all hot and bothered to buy the  Kasai Trading 2.3×40 mega-ultra-super-ridiculously widefield binoculars in my June 12, 2018 post.  Well, unfortunately for me, real life intervened and put the kibosh on that plan.  The fan in my furnace/AC unit stopped working.  I had to have repairs done, which wiped out all of the extra amount that the IRS had refunded to me.  I also learned that my heating and cooling systems are original to when the condo was built, 35 years ago.  Yikes!  So, no owl eyes for me.  Not for now, anyway.