This is a guest post from Darlene Cavalier, founder of Science Cheerleader and Science For Citizens and contributing editor at Discover Magazine.
If it’s sunny wherever you are today between 4:00 and 7:00 pm local time, contribute to science by taking a photo of a blank white piece of outside in the sun (try to avoid cloud cover). Your photo will be used in an informal study to measure how much of the sun’s energy is reflected back into the skies from the Earth — our planet’s “albedo.” It’s one way scientists can monitor how much energy – and heat – is being absorbed by our planet.

Here is what you need to do to participate in this citizen science project on ScienceForCitizens.net (a partner of Discover Magazine , NBC Learn, and the National Science Foundation’s Changing Planet series):

Today, (August 5, 2011) take a photo between 4:00 pm and 7:00 pm local time. Put a white piece of paper on a flat surface. The white paper should fill 1/4 to 1/2 of the total view. Do not cast a shadow on the image. Snap a digital photo. No flash.

Simply upload your photo here, and include your location (either city/state or latitude/longitude) and description of the background surface (grass, sand, etc).

Albedo is measured by comparing the response of the white card to the response of the ground surface. Data points will be depicted on a map later. We’ll let you know when the results are ready!

There will be more opportunities to contribute to albedo measurements in the future.Sign up to be notified about the next study!