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GLOBE at Night:GLOBE at Night: A Citizen-Scientist A Citizen-Scientist

Night Sky BrightnessNight Sky Brightness

Program to Measure

Some slides adapted from the International Dark-Sky Association

Some images courtesy of NOAA

Connie Walker

National Optical Astronomy Observatory

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Light pollution is a globalissue with local solutions…

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…Increasing Over Time(Cinzano, Falchi, and Elvidge 2001)

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Los Angeles in 1908

& 1988, as seen

from Mt. Wilson

Observatory

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A Little Sky Glow CanMake All the Difference

Before Curfew After Curfew

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Shielding the Streetlight- a Demonstration

• Make sure you are in a very dark roomwith a low ceiling and a white surface.

• Unscrew the reflectors from both “mini-lights” and turn 1 on (“candle mode”).

• Place the bulb top of the “mini-light”barely into the big hole at the bottom ofthe white paper cube.

• With the room lights off, project the“stars” from the white paper cube ontothe ceiling.

“candle mode”

Planetarium withlight inside

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Shielding the Streetlight- a Demonstration

continued…

• Using a 2nd “mini-light” as a “streetlight”, place it on a table and turn iton.

• What do you notice about thenumber of stars?

• Now place the PVC cap (or anothershield) above the 2nd “mini-light” torepresent a shielded streetlight.

• What difference do you notice withand without the shield?

“streetlight”

shielded light

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Now you see the person…

Now you don’t…

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Unshielded vsShielded Fixtures

Unshielded

• Minimizes glare.

• Minimizes lightdirected upwardand skyglow.

• Minimizes lighttrespass.

• Minimizes energyuse & cost

Shielded

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Light Trespass

Sky Glow

3 Main Types of

Light Pollution

Glare

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Issues of Safety, Security

and Energy

12The lights of the city of Tucson, Arizona, USA, as seen from the observatory on nearby Kitt Peak

The Effects on Astronomical Research

The Effects on Wildlife

One main problem light pollution causes for wildlife:

disorientation (sea turtles, birds, moths etc)13

The Effects on

Human Health

One main problem light pollution causes for humans:

disruption of people’s 24 hour internal clock (circadian rhythm)14

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What can you do?

Light pollution may be a global problem,

but you can be part of a local solution…

Feb. 5, 2008 NSN Telecon on GLOBE at Night 16

Use Quality Lighting

• See the effect, not the source.

• Shine the light down.

• No glare.

• Light only where and when needed.

• Don’t over light.

• Use energy efficient sources.

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The GLOBE at Night Program:

2 Ways to Participate

! The “classic” GLOBE at Night

observations that anyone can

have fun doing with their

unaided eyes

! An effort to obtain more precise

measurements of the night sky

using digital sky-brightness

meters

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The GLOBE atNight Program

• To learn about the impact of artificial lighting on towns and

cities, and the ongoing loss of a dark night sky as a natural

resource for much of the world.

• Citizen-scientists (YOU!) record the brightness of the night

sky by matching its appearance toward the constellation

Orion with charts of different limiting magnitudes.

• You can also measure sky brightness with Sky Quality

Meters.

• Measurements are submitted on-line and resulting maps

of all worldwide observations are created.

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Almost 7000 measurements,over 60 countries

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The Globe at Night Websitehttp://www.globe.gov/GaN/

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Steps to Observe

(unaided eye observations)

• Step #1. Find the constellation

Orion; note sky conditions

• Step #2. Match night sky to a

magnitude chart

• Step #3. Report your obser-

vations on-line

• Step #4. Input your latitude

and longitude

• Step #5. Compare your observation(s) to thousands

around the world

http://www.globe.gov/GaN/observe.html

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Step #1: Find YourLatitude & Longitude

• Use a GPS unit where you take ameasurement.

• Visit http://eo.ucar.edu/geocode/,http://www.earth.google.com, orhttp://www.itouchmap.com/latlong.htmlon-line. Input your location. Or inputyour city; zoom in/out and pan arounduntil you find your location.

• Use topographic map of your area.

• Determine your latitude and longitudewith the interactive tool when reporting

http://www.globe.gov/globeatnight/observe_latlong.html

Find Your Latitude & Longitude

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•Determine the darkest area where themost stars are visible.

•Wait 10 minutes for your eyes to darkadapt.

•Comment on the sky conditions & yourobserving location, such as street lights.

http://www.globe.gov/globeatnight/observe_finder.html

• Locate Orion with Finder Charts at www.globe.gov/globeatnight/observe_finder.html.

• Between March 16-28, 2009, Orion will be midway between South& West. Orion will be 2 to 3 clenched fists (held at arm’s length)above the horizon between 7-10 pm. Orion looks like an “hourglass”.

Step #2: Finding Orion©

T.

Cre

dn

er

& S

. K

oh

le, A

llth

eS

ky.c

om

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Step #3: Match Night SkyStep #3: Match Night Sky

to a Magnitude Chart.to a Magnitude Chart.

Estimate cloud coverageEstimate cloud coverage..

Fill out the observationFill out the observation

sheet.sheet.

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Step #4. Report

Step #4. Report

observations on-

observations on-

line.line.

Observe anytime

Observe anytime

between March

between March

16-28, 2009.

16-28, 2009.

Do it again fro

m a

Do it again fro

m a

different lo

cation!

different lo

cation!

/report.cfmhttp://www.globe.gov/globeatnight/report.html

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85 miles 5 miles

Zoom in with “Map Viewer”

It is important to have many observations at about 1 km to 1mile apart. Then we can map out light pollution within cities…and show how safe, quality lighting can make a difference inprotecting night skies!

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Zoom in with “Map Viewer”

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Helpful Information

• Brightness or magnitude of

stars

• Finding Orion (interactive tool)

• Orion mythology

• Light pollution

• How number of stars changes

with light pollution and

how latitude affects the

orientation of Orion

(interactive tool)

http://www.globe.gov/GaN/learn.html

30July 19th, 2008 ALCON 2008

LP

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Data Input for GLOBE at Night

• REQUIRED INPUT:

– Date and Local Time !!!

– Latitude and Longitude

– Unaided eye observation

– Meter Reading!(from Sky Quality Meter)

• OPTIONAL INPUT

– Various additional comments

http://www.globe.gov/GaN/report.html

Report Form

DateTime

Orion data

SQM entry

SQM serial

number

Lat/Long

http://www.globe.gov/GaN/report.html

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The Sky Quality Meter

! Press start button

here:

! Light enters

here:

! Read-out numbers

here:

http://www.globe.gov/GaN/learn_SQM.html

The SQM is Easy to Use!

• Point the SQM’s sensor straight up

(toward zenith).

• The SQM should be held at or above

head level so that shadows or

reflections from your body do not

interfere with the reading.

• Avoid using in areas that are shaded

by trees or buildings or lit by lights.

Be at least as far away from those

objects as they are high.

• After you press the button to take a reading, the SQM will beep

while it is accumulating photons. The beeping will stop once the

reading is ready to be viewed.

http://www.globe.gov/GaN/learn_SQM.html

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What do the Sky QualityMeter Readings Mean?

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What to Watch Out ForWhen Using the SQM

• 4 other numbers are displayed when youpress and hold the button a second time:

The temperature in °C and °F andthen the model and serial numbers

• The meter readings are somewhattemperature dependent.

_ Leave the meter outside for a coupleof minutes before taking measure-ments depending on the temperaturedifferential.

_ the SQM company advises to toss outthe very first measurement.

• You should have an Orion measurementfor every SQM measurement.

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Unaided Eye Observationswith Population Density (Tucson)

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Take Back the Night!Participate in the

GLOBE at Night Campaign

• At least 2 out of 5 Americans have neverseen 90% of the stars in our night sky.

• With half the world's population now living incities, this problem is only getting worse.

• Yet you can easily be part of a local solutionto a global problem.

• Become a local coordinator.

• Take a few minutes to monitor your localnight sky brightness.

• Help preserve our natural heritage forgenerations to come.

GLOBE at NightHow Many Stars?

Great World Wide Star Count• GLOBE at Night

Next GLOBE at Night campaign is March 16 - 28, 2009

Orion and Sky Quality Meters

www.globe.gov/globeatnight/

! How Many Stars?

Jan, Feb, April-Sept, Nov, Dec 2009

Little Dipper and 3 belt stars in Orion

www.sternhell.at/

! Great World Wide Star Count

Oct. 9 - 23, 2009

Cygnus and Sagittarius

www.starcount.org 39

Dark Skies Awareness

Global IYA Cornerstone

PROGRAMS

Citizen Science, Star-HuntingCitizen Science, Star-Hunting

Programs (e.g. GLOBE at Night)Programs (e.g. GLOBE at Night)Education ToolkitEducation Toolkit

Earth Hour Planetarium Show

Quiet Skies Traveling Exhibit, Posters, Brochures

Earth & Sky Photo Contest Great Switch Out

Dark Skies Discovery Sites Second-Life, Facebook, MySpace

Nights in the (National) Parks Podcasts

International Dark Sky Week &

World Night in Defense of Starlight

International Dark-Sky Communities,

Parks, & Reserves

www.darkskiesawareness.org 40

Thank-you foryour kind attention!

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For more information

! Websites of interest:www.darkskiesawareness.org

www.globe.gov/GaN/

! Contact: Connie Walker1-520-318-8535 or

cwalker@astronomy2009.us

QUESTIONS?

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