The satellite imagery you view on online mapping services doesn't display live views of planet Earth. The image you see may show structures that no longer exist or vacant lots where newly constructed buildings stand. As of 2012, Google Maps had amassed more than 20 petabytes of visuals -- approximately 21 million gigabytes -- including satellite imagery. The sheer volume of information required to display these satellite views slows the pace at which these sites update their imagery.

Google's Mapping Options

Google Earth provides in-depth mapping visualization that exceeds the online views you can achieve through Google Maps, but the two services share satellite imagery. Google Earth requires you to install a stand-alone application on your computer, whereas Google Maps runs in a Web browser. The satellite data you see on these services is typically one to three years old. Images shot from low-flying aircraft show detailed overhead views of individual buildings. The street-level views that can display individual cars in parking lots and residential driveways use a separate set of imagery provided through on-the-ground camera vehicles.

Google Maps Street View

The Street View option in the online Google Maps service shows you the view from a curbside or the middle of a thoroughfare. When you activate Street View to take a closer look at a scene, you can use the information included near the copyright notice that appears at the bottom of the window to find out the month and year in which Google captured the specific view. If you click on the directional arrows that appear over a road, the scene advances as if you were driving along the road. In some cases, as that view changes, it also switches from one imagery capture date to another.

Bing Imagery

Microsoft's Bing Maps originated as Microsoft Virtual Earth. Its satellite imagery reserves draw from a different bank of satellite photos than the ones you see on Google's mapping tools. In 2012, Microsoft more than doubled the amount of satellite imagery available through Bing, increasing its global as well as its U.S. coverage. The following year, Microsoft added high-resolution imagery of the ocean floor and upgraded its regular land-based satellite views. In December 2013, Microsoft launched Bing Maps Preview, which provides the kinds of street-level views and navigational routes featured in Google's mapping coverage. To get an estimate of an image's date for Bing Maps, try the Bing Aerial Imagery Analyzer at http://mvexel.dev.openstreetmap.org/bing/.

Other Considerations

If you purchase static copies of satellite views of a specific location for use in a project or on a website, you may be able to gain access to a wider time range of imagery and to select among various types of satellite visuals. These may include views that offer even higher resolution than the 15-meters-per-pixel views you see on online maps that display satellite imagery. The higher the resolution, the higher the price these digital products typically command.