Sky not as dark anymore

fuso (Anthony) · #1 24-10-2009, 10:21 AM

Hi guys,
Got a strange question for you all.
About 5 years ago I moved to melton and quickly noticed how dark the sky is compaired to outer melbourne. I enjoyed many dark nights with my 10x50 binos looking at DSO and comets. After a few lazy years (kids and fishing came), this year I got my self some 20x80 bios and hopped back into star gazing.
The last few night I have noticed that the sky is not as black as I remebered

.

What would be the cause of this?
1. More houses? (I hope not)
2. I was out to early? (stargazing at 10pm)
3. Just the atmosphere?
4. Summer nights arent as dark as winter ones?

Some answers would be appreciated befor I jump in and buy a 10" Dob.

Many Thanks Anthony

DavidU (Dave) · #2 24-10-2009, 10:39 AM

True! More roads means more street lights, more houses means more shops all lit up.
Last night was very good seeing so it's probably as good as it gets.

acropolite (Phil) · #3 24-10-2009, 10:42 AM

More air pollution means more scattering of light as well.

Starkler (Geoff) · #4 24-10-2009, 10:51 AM

Theres certainly a lot more light out my way than there was 5 years ago.
Outer Melbourne is creeping outward and new estates have popped up everywhere out my way

The other thing is that sky darkness will vary from night to night depending on the amount of dust and water vapour in the air. We call this 'transparency', and its usually best after a good rain.

leon · #5 24-10-2009, 08:57 PM

I have noticed this as well, and have found that the very best times for imaging and viewing is well after midnight, till dawn.

Leon

dpastern (Dave Pastern) · #6 24-10-2009, 09:00 PM

D: all of the above

(aren't I cheeky lol)

Dave

stephenb (Stephen) · #7 25-10-2009, 07:38 AM

I believe it's the spread of population growth in the outer surburbs of Melbourne.

GrahamL · #8 25-10-2009, 09:30 AM

I am blameing the Architects.

As an example around where my parents live in brisbane borders an area of light to mediumm industry , 20 years back the sky was pretty dark of a night everyone turned of the lights and went home , today
the sky is just completely washed out , but in that same area there is likely not many more people than there where 20 years ago.

Most of the courses have a componant of the studiies directed to useing lighting in design, and use it they do!!.. go for a drive round a fairly new industrial estate at night and have a look see, I see empty buildings with lots of pleasant and astheticly appealing looking
lighting shineing on , out and around thereof.. and every year they churn out more sheep who are going to do more of the same .

we have to deal with them IMO

and soon !!!!

taminga16 (Greg) · #9 25-10-2009, 10:58 AM

With all of the noise being made about Greenhouse Gas reduction and taking into account that turning off a light (or lots of lights) is an instantly measurable form of pollution reduction that benefits not just the atmosphere, but the general quality of life and night sky viewing of course, Why are we not encouraged to do so? I fear that the brown coal stocks are still too great and until we get to the stage where people ask "What Happened"? Nothing Will.........

Greg.

P.S. There is an Architectural Lighting Code in place in Victoria, but weather it is practiced or enforced is another question.

multiweb (Marc) · #10 25-10-2009, 02:56 PM

Yeah it's getting brighter everywhere. 15 years ago I could see the milky way and the L/SMC from my backyard in Liverpool no worries. Now it has to be a real good dark night with good seeing to make out anything. That was before the M7 and all the new industrial/residential areas. Light policies or better designs would definitely make a big difference. With all the "climate" and energy preservation debates you'd think they'd do something about all the energy that's going up in smoke at night lighting up places that don't need to be? "leaving the light on" seems to be now something that's accepted as being normal. That's BS IMHO. You don't use or need it, switch it off.

dpastern (Dave Pastern) · #11 25-10-2009, 03:31 PM

I agree Marc, sadly, we have the "security" minded people that are demanding that lights be on 24/7. Given the likely introduction of CCTV cameras in all areas (to combat crime of course, please note the sarcasm in my voice), lighting will be required. It ain't gonna change, in fact, it'll probably get worse.

Dave

Robh (Rob) · #12 25-10-2009, 04:05 PM

This is an ever-increasing problem with the spread of more suburbs.
Most street lights produce a light cone whose apex angle is near 180 degrees, which is ridiculous. The result is that the light can be seen hundreds of metres away at right angles to the street from the light pole, in directions the light is not required. Appropriate shielding should only allow light onto the paths and road surfaces they are intended for.

Regards, Rob

multiweb (Marc) · #13 25-10-2009, 04:09 PM

May be limiting the power of the lights would help. We don't need them full blast. People vision would get used to dimmer lighting. That would be something easy to do? Regulate an existing network rather than changing or redesigning the whole thing?

Robh (Rob) · #14 26-10-2009, 01:05 PM

Seriously though, street lights in new suburbs could be installed, properly shielded, to reduce skyglow. Lights in older suburbs could gradually be replaced over time with correctly shielded lamps. And as Marc stated, only the minimal power lamps required.

Rob

DavidU (Dave) · #15 26-10-2009, 01:39 PM

Quote:

Originally Posted by Robh

Seriously though, street lights in new suburbs could be installed, properly shielded, to reduce skyglow. Lights in older suburbs could gradually be replaced over time with correctly shielded lamps. And as Marc stated, only the minimal power lamps required.

Rob

I wish they would ! I have one very bright street light on my nature strip

bmitchell82 (Brendan) · #16 26-10-2009, 03:30 PM

make them use those poxy energy saving lights

that would dim the LP down

hahahaha

Starkler (Geoff) · #17 26-10-2009, 07:26 PM

Quote:

Originally Posted by bmitchell82

make them use those poxy energy saving lights

that would dim the LP down

hahahaha

Lol that immediately made me think of how the government tries to badger us into using those low flow and horribly unsatisfying water saving shower heads. Take the same philosophy into public lighting I say

Jen · #18 26-10-2009, 08:14 PM

gday Anthony
Yeah i think all the above too
But hey what the heck go out and buy that 10" dob anyway

pgc hunter · #19 26-10-2009, 08:25 PM

Victorian street lighting is a shining example of crap design. bulbs are held in casings which expose them entirely rather than inside the fitting directing the light downwards at a 90º angle which is what would be ideal. The bulbs can be seen even when one is at eye level with the light fitting.

Also, all overhead road signs here in Lightoria are lit from the bottom up, rather than top down. Legendary. The ideas man behind this needs a nobel prize for logic.

And then ofcourse there are the clowns who must burn their 10 billion watt floodlights so their little Sh1tzu can see where it is dumping its load.

mithrandir (Andrew) · #20 26-10-2009, 09:37 PM

Quote:

Originally Posted by DavidU

I wish they would ! I have one very bright street light on my nature strip

A length of timber/bamboo, a few lengths of rope, tent spikes and a piece of board painted black?