Sunday, May 07, 2017
Issue 540: Get Thee to a Dark Site II
Last ish we got you a dark site, or at least gave a few
pointers as to how you and your fellow astronomy club members could find and
keep one. This time, we’re going to talk about using that site.
And you know you want to use it. Sure, in this day of electronic
cameras and computer processing you can take pretty good pictures from the
backyard, but you’ll always get better results under dark skies. Visual
observer? As I said last week, the galaxies of spring cry out for the darkest
skies possible.
There is no doubt about one thing, spring weather in the
USA, and especially east of the Mississippi, can be capricious. Before talking
about what you bring to your club’s observing field and what you do there,
maybe we should discuss “whether.”
Obviously, if you’ve got beautiful blue skies and the
forecast is for more, a dark site trip is a natural. But what if the sky is
unsettled and the weather forecasts ambiguous? Back in the day, back when I was
more sanguine about hard-core observing, back when I lived downtown and couldn’t
observe anything from my backyard, I had a rule, “If it ain’t raining, head to
the dark site.”
That stood me in good stead for years, and resulted in me
seeing far more than I would have if I’d let a few clouds scare me off. Most of the
time—though certainly not all of the time—I at least saw something at the club site in return for an hour’s journey into the
west. I would sometimes wimp-out
observing plan and gear-wise, though. If the sky really did look doubtful, I’d
tend to change my plans from “astrophotography” to “visual,” and the telescope
from my C11 to my 5-inch ETX Maksutov Cassegrain, Charity Hope Valentine. Anyway, I always found that even if I was mostly skunked, I had a better out on the observing field than I
would have had sitting at home watching television.
Let’s say, you’ve got a night that looks to be
uncompromisingly good, though. What do you load into your vehicle? The simple answer is
“everything you need, nothing you don’t.” Certainly you want all the gear you
require to allow you to execute whatever your observing plan is, but there are
things you’d take to a multi-night star party that you will likely want to leave
at home for a club site run. Remember, you’re going to have to pack all that
stuff back into your car at the end of the evening and possibly unload it at
home.
What NOT to Bring to a
Dark Site…
Observing table
You may actually need an observing table depending on your vehicle and
what you are doing, but maybe you can back off from a big camp table to a
TV tray. If I am doing visual observing, a table just large enough for an
eyepiece box and maybe a star atlas is more than enough. Imaging? I’ll need
something to put the laptop computer on, but not anything more than that.
When I switched vehicles from a sedan (a Camry) to a
truck/SUV (4Runner), I eliminated observing tables altogether, operating out of
the back of the 4Runner, tailgating it as it were, which is the best of all
worlds—I even have AC power available there from the truck’s built in inverter
and auxiliary battery.
Computer
This is a maybe/maybe not thing. Even if you are doing
imaging, you may be able to eliminate
the laptop. Using a standalone auto-guider and a digital single lens reflex
(saving images on the camera’s memory card) can allow that. By saying “ixnay”
to the laptop, you can also leave one large battery at home (a laptop’s
internal battery will rarely last an entire observing run), the above mentioned
table, cables, mouse, mousepad, etc., etc., etc. Yes, it’s nice to have a computerized
star atlas like Stellarium, but in the interests of simplicity, sometimes I don’t
mind getting reacquainted with Sky Atlas
2000 or Uranometria. Just can't go back to that? SkySafari running on a tablet is a good compromise.
Stuff you always
bring and never use
You tend to throw a pair of binoculars in the car, but
never/rarely use them? Leave them at home. The same goes for stuff like extra
flashlights, a second box of eyepieces, radios, ice-chests, etc. All that junk
is nice at a big star party, but you are not going to be at the dark site long
enough to feel the need for this stuff.
A telescope that is
just too much
Small can be beautiful... |
We all want to maximize our observing experience, but if a
telescope is so large and/or complex, that by the time you get it assembled and
working it’s time to go home, leave it at home. Give me a freaking C8 for dark
site use not a C11 or (horrors) C14. When all your buddies are packed up and
ready to hit the road and you still don’t have the scope off its mount, I think
you’ll begin to believe that sacrificing some aperture and/or features might
not be such a bad idea.
Things that will
annoy your fellow observers and possibly the landowner
Radios blasting your particular preference in music and green
laser pointers that make the sky look like something out of Return of the Jedi have no more place at
the club dark site than they do at a big, organized star party.
What to Bring
A Telescope
Sure, you know to pack the telescope, but make sure you pack
all of it. One night, one cloudy night, when it wasn’t raining, nevertheless, I
headed to the dark site with my C11. As soon as I arrived onsite, almost magically
the clouds began to scurry off and I began assembling my big scope. Yes, as
above, it was really too much for a short dark site run, but I was younger,
stronger, and dumber then.
I had just got the NexStar 11 GPS on her tripod when I had a
vision. Of the telescope’s hand control sitting on the dining room table of
Chaos Manor South. And that was just where I’d left it. What to do? There
wasn’t anything to do. I packed up and went home. I was just thankful I wasn’t
at a star party 400 miles away.
In the interests of this sort of thing not happening to you,
it’s a good idea to have a checklist. If you know an item is necessary, put it on
the list and don’t check it off till it is packed in the car.
Power
A telescope that doesn't need batteries can be nice sometimes... |
Some lucky folks have AC power available at the club site,
but that is rare. Be prepared to operate off batteries all night. So, ensure
your batteries are fully charged beforehand. Don’t just assume they are. What
sort of batteries? I favor the ubiquitous 17ah jump start battery packs. Not
only do they have enough juice to power most scopes and accessories all night,
they usually have built in lights which are handy when you are packing up at
the end of the evening. Yes, don’t take too much stuff, but don’t scrimp on
batteries. I always take one for the (goto) scope, one for the dew heaters, and
one for the laptop.
Dew Heaters
At home, in my backyard, I can often get by without a dew
heater system on my SCTs and refractors. My house and neighboring houses and
trees shield much of the heat sucking sky from the view of my scope, acting as
giant dew shields. On an open field out in the country? Uh-uh. Even if your
area is drier than my Gulf Coast stomping grounds, you’ll need something to
keep dew off.
Dew prevention is a subject for an entire article, but I can
offer some basic guidance here: use
heater strips on objective or corrector. If all you have is a dew-zapper
gun—a 12 vdc hair drier cum window defroster—you will soon lose the battle
against dew. A zapper can be sufficient for the secondary mirror of a Newtonian
reflector, however.
Observing Chair
You’d think this would be something I’d tell you to leave at home,
but it isn’t. Even for a relatively short visual observing run, being
comfortable means you will see a lot more. Bring the chair along.
Accessories
Use that checklist to make sure you bring the vitals: eyepieces, star diagonals, star charts (or a
smart phone or tablet), red flashlights, etc.
Don’t overdo. I restrict myself to one eyepiece case and one accessory box (a
large Plano tacklebox).
Insect Repellent
"If it ain't raining." Sometimes you eat the bear, and sometimes... |
Whether “just” a can of Deep Woods Off, or a Thermacell, don’t
even think about heading to the dark
site without bug zappers except in the very depths of winter.
A Coat/Jacket
“But Uncle Rod, it’s only gonna get down to the lower 70s.”
Bring a coat or sweater or sweatshirt anyway. You will never be colder than
when standing nearly stock still at a telescope under an open sky. Let it get
to the mid-60s and you will begin to shiver and will throw in the towel unless
you are prepared.
Cell phone
Don’t just always bring your cell phone with you as we insisted
last time, make sure it is fully charged before leaving home. Taking a DC
charger to the site might not be a bad idea either.
A Few Amenities
You won’t be out there that long, so don’t pack too much
additional stuff, but certainly a few bottles of water and maybe even a couple
of snack items is “reasonable.”
Setting Up
It’s your dark site, set up anywhere you like, right? Sure.
But some places are better than others. If there’s been a recent rain, you’ll
be better off on your field's high ground if it has any. You probably don’t want
to be on a slope, however; telescopes are happiest on level ground. One other
thing? Togetherness is fine. You want to be close to your buddies so you can
share observations, chat, etc. However, if you’ve only got a few people at the
site there’s no need to set up 3-feet from the next scope. Spread out and give
each other some room.
Observing
You observe the way your normally observe at home or at a
star party. What I’m really talking about here is observing rules. Your club probably needs to come up with a few.
You want to prohibit white light and probably green lasers. But you don’t want
to keep adding so many rules that people feel stifled. And be aware that at a
club site with two or three people on the field, all those beloved rules formulated
at that marathon club business meeting are likely gonna be observed in casual
fashion at best.
For example? You wouldn’t dare fire up your vehicle and drive off a star
party field at midnight, but at the old dark site with a few people around?
It’s likely to be, “Had a great night Wilbur! See you next time, Hiram! Gotta
head on home.” If everybody’s observing visually they
can shield their eyes while you motor off. If someone’s in the middle of an
astrographic exposure, wait until they are done. Just use common sense—and the
same goes regarding any rules you and your mates think up.
Packing Up
The Moon is rising, or it’s just late, or it’s just you and
your friends’ usual turns-into-a-pumpkin time. What about tear-down of the
equipment? If, as above, you have to leave earlier than your pals, you’ll need
to pack by red light (one of those red LED head-lights on a head-band is
good if you keep it pointed at the ground).
You'll soon tire of using a dew-zapper gun... |
Anyway, when the time comes, disassemble your scope, taking
care that everything gets back into the vehicle. I tend to be a little less
than scrupulous about putting every widget back in its proper place in the cases;
I just shovel it all into the car so as not to delay my friends, and worry
about sorting everything out the next morning (I can leave all my stuff in my
car overnight thanks to a safe and secure neighborhood).
Once everything is back in the car, go over your area
carefully with a white light to make sure nothing got dropped and that you’re
not leaving any trash behind. Help your fellows out with the same thing.
Then—well, you’re off for home (or perhaps your favorite late night bar out in
the boondocks).
You’re off if everybody
is ready to go, that is. One rule our club has made and that we observe
scrupulously is, “Nobody leaves till everybody leaves.” Obviously that doesn’t
apply to someone who has to go early for whatever reason. It just means
those of us left at the end of the night linger on till the last person has their
gear packed. That’s good for security’s sake, but even if, like us, you have a
very safe dark site it’s still a good rule to live by. What if the last person
standing has trouble getting their vehicle started?
Then, just say your goodbyes, “Great time, y’all! See you
next time.” If you did everything right, and your club has the “right” site,
believe me, you’ll hardly be able to wait for next time.
Comments:
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Nice article, as usual, Rod. I have to smile at your obvious, southern observer bias, though, regarding these past two installments. Snakes? Insects in all but the depth of winter? Security? Shivering at temps in the mid-60s?
Up here near the Canadian border you only have to deal with ravenous insects for 2-3 months each years, but DO have to be prepared for cold (serious, sub-zero cold) for 4-5 months. If the night is clear, it's almost always COLD.
ZERO cell phone reception is common, but so is the abundance of public, DARK sky sites (gravel pits, clear cuts, lake shores), as the vast majority of the landscape is in public ownership (state and national forests, etc.).
America is a big place, and it is fun to compare the regional challenges facing observers.
Up here near the Canadian border you only have to deal with ravenous insects for 2-3 months each years, but DO have to be prepared for cold (serious, sub-zero cold) for 4-5 months. If the night is clear, it's almost always COLD.
ZERO cell phone reception is common, but so is the abundance of public, DARK sky sites (gravel pits, clear cuts, lake shores), as the vast majority of the landscape is in public ownership (state and national forests, etc.).
America is a big place, and it is fun to compare the regional challenges facing observers.
Gotta tell you, Gordon, I'll take my bugs and snakes over your C-O-L-D any day. Why, I nearly froze one late summer night at the Northwoods Star Party (where I was a speaker). LOL
Wow Rod the US truly is a different country! I'm not sure we're allowed cars that big here in England. And you're suggesting I drive to Wales for a night out?
Love your articles, keep 'em coming!
Phil, Salisbury, UK.
Love your articles, keep 'em coming!
Phil, Salisbury, UK.
Awesome article. Just want to add for warmth, whether down south or up north, make sure you bring a hat of some kind. Best if it's a wool cap (toque in Canada) of some type that you can pull down over the ears. A classic Elmer Fudd cap rocks warming the head and the heart buying extra time under the skies when cold and/or wet. An extra pair of warm socks can also save the day when the grass gets dewy.
Cheers from way up north. JC
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Cheers from way up north. JC
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