Yesterday was the 40th anniversary of the Landsat system, a group of satellites that offer scientists a continuous view of the earth.
“The data from the satellites provide a permanent, objective record of land conditions and are routinely used to measure and monitor changes brought on by natural or anthropological events and actions,” according to the U.S. Geological Survey, which operates the system in partnership with NASA.
Here’s an example. Four decades ago, the system took this color infrared image of the Washington, D.C., area. “The red tones represent forests and large grassy areas. The light tones indicate cleared fields and the highly reflective impervious areas of urban development,” according to USGS:
Landsat also captured this image earlier in 2012. “A comparison of the two images illustrates the significant growth in the greater D.C. area,” the agency said:
Here’s the national view, with colors representing which group has a plurality in each county, and shades indicating the concentration:
More recent data shows other information collected last year by the bureau. This view, for example, is a national look at the percentage of residents who are married with kids in the home (notice Utah and South Texas — counties with the nation’s highest birth rates — have a greater proportion of these residents):
And, finally, if you zoom in, the map displays data at the block group level. Here’s D.C., which as I’ve noted is quite segregated:
I’ve been living here in Washington, DC, by myself for the last month, and exploring the new city in between the out of town trips for work. In between all the Metro rides to DCA, I’ve tried to remember and make note of the places I’ve been, so that when my husband (finally) moves to town we can go to some spots together (finally).
To plot where I’ve been, I created a personalized Google Map and made notes on each place. It’s a very simple data visualization, but I’m not the pro in the family. Check it out: