GLOBE at Night: a Citizen-Scientist Night Sky

GLOBE at Night: A Citizen-Scientist Program to Measure Night Sky Brightness

Connie Walker National Optical Astronomy Observatory

Some slides adapted from the International Dark-Sky Association

Some images courtesy of NOAA 1

Light pollution is a global issue with local solutions…

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

Los Angeles in 1908 & 1988, as seen from Mt. Wilson Observatory

4 A Little Sky Glow Can Make All the Difference

Before Curfew After Curfew 5

Shielding the Streetlight - a Demonstration

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

• Unscrew the reflectors from both “mini- lights” and turn 1 on (“candle mode”). “candle mode” • Place the bulb top of the “mini-light” barely into the big hole at the bottom of the white paper cube.

• With the room lights off, project the “stars” from the white paper cube onto the ceiling. Planetarium with light inside 6 Shielding the Streetlight - a Demonstration continued…

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

• What do you notice about the “streetlight” number of stars?

• Now place the PVC cap (or another shield) above the 2nd “mini-light” to represent a shielded streetlight.

• What difference do you notice with shielded light and without the shield? 7

Now you see the person…

Now you don’t…

8 Unshielded vs Shielded Fixtures

• Minimizes glare. • Minimizes light directed upward and skyglow. • Minimizes light trespass. Unshielded Shielded • Minimizes energy use & cost

3 Main Types of Light Pollution

Light Trespass

Glare

Sky Glow 10 Issues of Safety, Security and Energy

The Effects on Astronomical Research

12 The lights of the city of Tucson, Arizona, USA, as seen from the observatory on nearby Kitt Peak 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: 14 disruption of people’s 24 hour internal clock (circadian rhythm) What can you do?

Light pollution may be a global problem, but you can be part of a local solution… 15

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.

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

The GLOBE at Night 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. 18 Almost 7000 measurements, over 60 countries

The Globe at Night Website http://www.globe.gov/GaN/

20 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 observations on-line

• Step #4. Input your latitude and longitude

• Step #5. Compare your observation(s) to thousands around the world 21

Step #1: Find Your Latitude & Longitude http://www.globe.gov/globeatnight/observe_latlong.html

• Use a GPS unit where you take a measurement. • Visit http://eo.ucar.edu/geocode/, http://www.earth.google.com, or http://www.itouchmap.com/latlong.html on-line. Input your location. Or input your city; zoom in/out and pan around until you find your location. • Use topographic map of your area. • Determine your latitude and longitude with the interactive tool when reporting 22 Find Your Latitude & Longitude

Step #2: Finding Orion

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

•Determine the darkest area where the most stars are visible. AlltheSky.com •Wait 10 minutes for your eyes to dark ,

adapt. Kohle S. & •Comment on the sky conditions & your observing location, such as street lights. Credner

Locate Orion with Finder Charts at T. • 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 “hour glass”. 24 Step #3: Match Night Sky to a Magnitude Chart. Estimate cloud coverage. Fill out the observation sheet. 25

http://www.globe.gov/globeatnight/report.ht/report.cfm ml

Reporton- #4. Step observations line. anytime March Observe between2009. 16-28,

a from it againlocation!location! Do different

26 Zoom in with “Map Viewer”

85 miles 5 miles

It is important to have many observations at about 1 km to 1 mile apart. Then we can map out light pollution within cities… and show how safe, quality lighting can make a difference in protecting night skies! 27

Zoom in with “Map Viewer”

28 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)

July 19th, 2008 ALCON 2008 30 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

Report Form http://www.globe.gov/GaN/report.html Date Time Lat/Long

Orion data

SQM entry SQM serial number

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

! Press start button here:

! Light enters here:

! Read-out numbers here:

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

• 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. 34 What do the Sky Quality Meter Readings Mean?

What to Watch Out For When Using the SQM • 4 other numbers are displayed when you press and hold the button a second time: The temperature in °C and °F and then the model and serial numbers • The meter readings are somewhat temperature dependent. _ Leave the meter outside for a couple of minutes before taking measurements depending on the temperature differential. _ the SQM company advises to toss out the very first measurement. • You should have an Orion measurement for every SQM measurement. 36 Unaided Eye Observations with Population Density (Tucson)

Take Back the Night! Participate in the GLOBE at Night Campaign

• At least 2 out of 5 Americans have never seen 90% of the stars in our night sky. • With half the world's population now living in cities, this problem is only getting worse. • Yet you can easily be part of a local solution to a global problem. • Become a local coordinator. • Take a few minutes to monitor your local night sky brightness. • Help preserve our natural heritage for generations to come. 38 GLOBE at Night How 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-Hunting Education Toolkit Programs (e.g. GLOBE at Night) 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 & International Dark-Sky Communities, World Night in Defense of Starlight Parks, & Reserves

www.darkskiesawareness.org 40 Thank-you for your kind attention!

For more information

! Websites of interest: www.darkskiesawareness.org www.globe.gov/GaN/

! Contact: Connie Walker 1-520-318-8535 or [email protected]

42 QUESTIONS?