Vienna, Austria

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The IAU International Year of Astronomy
Cornerstone GLOBE at Night, How Many Stars

• Dark Skies Awareness

Gunther Wuchterl Connie Walker
Some slides adapted from the International
Dark-Sky Association Some images courtesy of NOAA
The World at Night
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Outline

• Light Shielding Demonstration (15 min)
• The GLOBE at Night Program (15 min)
• The GaN Web Site (10 min)
• How Many Stars? (15 min)
• The HMS Web Site (10 min)
• HMS Translation Tool (10 min)
• Break (20 min)
• The Sky Quality Meter (15 min)
• The Luxmeter (15 min)
• Discuss a joint concept for DSA Cornerstone

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Shielding the Streetlight- a Demonstration
Shielding Demo (in a dark room with a white
tabletop)
What difference do you notice with and without
the shield?
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Unshielded vs Shielded Fixtures

• Minimizes glare.
• Minimizes light directed upward.
• Minimizes light trespass.
• Minimizes energy use cost

Unshielded
Shielded
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Glare
3 Main Types of Light Pollution
Light Trespass
Sky Glow
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Our Globe at Night
Upward-facing lights Fog our starry
nights, Replacing natures creations with urban
constellations. Shed light on light pollution Be
part of the solution.
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Artificial Night Sky Brightness due to Light
Pollution (Cinzano, Falchi, and Elvidge 2001)
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Los Angeles in 1908 1988, as seen from Mt.
Wilson Observatory
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With Light Pollution Without

• before a power outage during a power outage

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Issues of Safety, Security
and Energy
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Lights can be a threat to astronomy.
The lights of the city of Tucson, Arizona, USA,
as seen from the observatory on nearby Kitt Peak
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The Affects on Wildlife
One main problem light pollution causes for
wildlife disorientation (sea turtles, birds,
moths etc)
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The Affects on Human Health
One main problem light pollution causes for
humans disruption of peoples 24 hour
internal clock (circadian rhythm)
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What can you do?
Light pollution may be a global problem, but it
has a local solution
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The GLOBE at Night Program

• To teach about the impact of artificial lighting
  on local environments, and the ongoing loss of a
  dark night sky as a natural resource for much of
  the worlds population.
• Citizen-scientists record the brightness of the
  night sky by matching its appearance toward the
  constellation Orion with charts of different
  limiting magnitudes.
• Measurements are submitted on-line and resulting
  maps of all worldwide observations are created.
• 20,000 measurements from almost 100 countries
  over two-week campaigns in 2006, 2007 and
  2008.

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European Countries Involved in GLOBE at Night
2008
NOTES 1320 measurements total 18 of all
measurements 4 countries gt 100
measurements
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Steps to Observe(unaided eye observations)
http//www.globe.gov/GaN/observe.html

• 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

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The Globe at Night Website
http//www.globe.gov/GaN/
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Match Night Sky to a Magnitude Chart. Estimate
cloud coverage. Fill out the observation sheet.
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Helpful Information
http//www.globe.gov/GaN/learn.html

• 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)

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Data Input for GLOBE at Night
http//www.globe.gov/GaN/report.html

• REQUIRED INPUT
• Date and Local Time    
• Latitude and Longitude
• Unaided eye observation
• Meter Reading (from Sky Quality Meter)
• OPTIONAL INPUT
• Various additional comments

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Report Form
http//www.globe.gov/GaN/report.html

Date
Time
Lat/Long
Orion data
SQM entry SQM serial number
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Almost 7000 measurements, over 60 countries
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Zoom in with Map Viewer
http//www.globe.gov/GaN/analyze.html
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Going Further
http//www.globe.gov/GaN/analyze.html

• Compare with other years of Orion and SQM data
• Compare with popula-tion density data
• Compare with Earth at night satellite data
• Bring results to your local government
  influence change!

Budapest, Hungary
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Two Kinds of GLOBE at Night

• The classic GLOBE at Night observations that
  anyone can have fun doing with their unaided
  eyes.
• An effort to obtain precise measurements of the
  night sky using digital sky-brightness meters,
  especially to identify and preserve urban
  dark-sky oases.

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The Sky Quality Meter
http//www.globe.gov/GaN/learn_SQM.html

• Press start button here
• Light enters here
• Read-out numbers here

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The SQM is Easy to Use!
http//www.globe.gov/GaN/learn_SQM.html

• Point the SQMs 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.

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STAY TUNED UNTIL AFTER BREAK FOR AN OPPORTUNITY
TO USE THE SQMS.
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For more information

• Websites of interest
• www.astronomy2009.us/darkskies/
• www.darkskiesawareness.org
• www.globe.gov/GaN/
• Contact Connie Walker
• (IYA Dark Skies Awareness Chair)
• 1-520-318-8535 or
• cwalker_at_astronomy2009.us