Google Earth: The city lights


The “Earth at Night” layer remains a very unique way to view the earth. Captured on the “dark side” of the planet, depending on the time of day, the images are a striking visual of the more urbanized areas of the planet.



However, the images were not easy to capture. For years, astronauts would try to capture the bright lights and only have blurry photographs to show for it, as the earth travels beneath them at 4.4 miles/second.

In 2003, Don Pettit developed an innovative system for capturing these images and he went on to capture over 2,500 photos, with thousands more captured in subsequent missions. You can read more about Don and his technique in this article at Air & Space Magazine.

To see the lights for yourself, simply click on the [Layers] in Google Earth, open [NASA], then [Earth City Lights] and click the button in there.. For the best results, disable your other layers and places to get a nice clean view of the earth. You should likely disable the atmosphere as well (under [View] –> [Atmosphere]), but I kind of like the glow it gives. It’s a neat effect.

A big thanks to Don for pioneering this amazing technique, and hopefully as time goes on this imagery will become even higher-quality and more striking.

Garmin: Which watch fits fitness fans?


Every give-a-Garmin season, I hear a chorus of questions from friends and family seeking insider shopping tips. This week, I heard from Kathy, who heads up our local Girls on the Run council. She wanted to know what to get hubby Mark, who keeps his fitness in check with daily walks and wants to log every mile and minute. I had two picks: the sleek and stylish Forerunner 210, which tracks distance, time, pace and calories and comes with or without heart rate. For upcoming “snow days” when he can’t get outside, he canpair the 210 with the optional foot pod to track distance indoors.

My second pick is another wrist-worn wonder: the Approach S1 golf watch. I know Mark loves his time on the greens, and since Approach S1 is GPS-enabled, it could double as his distance tracker on and off the course. For golfing, it measures distance to the front, back and middle of greens for more than 17,000 preloaded courses.

I’m also recommending the newest Forerunner 210 with teal accents for a friend and for my sister. They’ve both been very good girls this year and get to check off “half marathon” from their 2011 resolution list. I like the Forerunner 210 for them because it’s super easy to use, gives accurate distance and pace data and it looks good/feels good. And for runners who want a little more, it offers customized interval sessions to guide their speedwork.

Google Earth layers – NASA’s Earth Observation

NASA’s Earth Observation site dozens of layers of the global scientific data is formatted for viewing with Google Earth.

These are grouped into the ocean, atmosphere, energy, land, and the Life category. The layers are too many to list, but they include:

Sea surface temperature
Chlorophyll concentrations (MODIS)
Snow cover and sea ice extent
Cloud water content (MODIS)
Total precipitation (TRMM)
Water vapor (MODIS)
The temperature of the land surface
Active Fires (MODIS)
Land cover classification (MODIS)
Vegetation index [NDVI] (MODIS)
The population density

The layers are highlighted in red above were combined into a single network link, which you can download the screenshot below. This will give you a preview of some of the available data. Visit NASA’s Earth Observing site other overlays the data.

Download .KML file