MeasureTheSkyBC

MeasureTheSkyBC is a citizen-science campaign to raise public awareness of the impact of light pollution by inviting you to measure & submit night sky brightness observations for locations in British Columbia. For some added incentive we are offering a chance to win prizes to citizen-scientists who email their measurements to [email protected].

It’s easy – all you need is computer, tablet, or smart phone & your eyes!

Share your results and experience on social media with the tag #MeasureTheSkyBC

Get an App

GlobeAtNight: https://globeatnight.org/webapp/

  • Easy to use web application
  • Asks you to compare how your sky looks compared to a series of star charts for a bright constellation
  • Takes just a few minutes to make a measurement
  • Needs internet access

Loss of the Night on Apple App Store (iPhone) or Google Play Store (Android)

  • Guides you to specific stars and asks if they are visible to you.
  • Measurement uses 8 stars (or more) and may take 10-15 minutes
  • More accurate and improved accuracy with more stars
  • Not designed for very dark locations
  • Internet access is not required

Dark Sky Meter: on Apple App Store ($2.79)

  • Easy to use: uses your iPhone’s camera
  • Just two button pushes to take a measurement
  • iPhone only
  • Does not require internet

Win Prizes

Submit your measurements using the App but also also email them to [email protected] for a chance to win a prize – The email can include more than one measurement but please include your name, and the location, date, and time for each measurement.

Prizes will be awarded every month from June through to September 2019 using a random selection from all measurements submitted up to the end of the month.

The more measurements you submit the greater your chance of winning!

Prizes Include the following.

Free Registrations to Manning Park Astronomy Weekend – Courtesy of Manning Park Resort

Manning Park’s second annual astronomy weekend, featuring workshops, speakers and star-gazing.

October 18-20 & 25-27, 2019

Explore the Universe Guide 2nd Edition

If you are just starting out in astronomy, the ETU Guide is for you. This illustrated book answers questions about astronomical coordinates, constellations, eclipses, the Moon, major and minor planets, comets and more.

Space Posters

… and more to come!

What are Magnitudes?

Image Credit: Sky & Telescope



The magnitude of an astronomical object is a measure of how bright it appears to an observer on Earth. It depends both on the the object’s intrinsic brightness and its distance from Earth.

The magnitude scale is relative where brighter objects have lower magnitudes – the brightest objects have negative magnitudes. For example, the Sun’s is magnitude -26, Venus is about -4.0, the bright star Sirius is -1.4.

The faintest stars that we can see with our naked eye are between 6-7 depending on the observer’s eyesight, their dark adaptation, and the darkness of the skies. In a light polluted city, the faintest detectable stars might be magnitude 3.5 or less.

When looking at the sky, the darker the sky, the more faint stars you can see, hence the limiting magnitude is greater. And this indicates less light pollution!

Measurement Tips

  1. Go outside more than an hour after sunset
  2. The Moon should not be up.
  3. Let your eyes become used to the dark for 10 minutes before your first observation.
  4. People using mobile phones are less aware of their surroundings, so you should never use the app alone outdoors at night! Always take a friend to watch out for potential hazards while you are using the app.

The apps can show you the measurements made on a device or you can view all measurements on different maps:

Visit Dark Sky Sites in BC

You can take measurements anywhere but the following are some of RASC’s favourite dark sky sites and events that are close to the lower mainland, Pay them a visit to experience dark skies.

Porteau Cove Provincial Park

Manning Park Dark Skies

Merrit Star Quest

Mount Kobu Star Party