The ArcGIS Explorer default map, and other maps and layers found on the ArcGIS Explorer Resource Center, are regularly updated. These services come from ArcGIS Online and updates are managed by the ArcGIS Online team. ArcGIS Online also offers a variety of map services available for ArcGIS Desktop and ArcGIS Server users.

Some of these changes are subtle (but still important) and others are dramatic. Here's one that we noticed earlier today when taking a look at one of the demonstrations shown during the User Conference plenary.

During one of the demonstrations we took a look at a bridge near Phoenix. In the Explorer default map the imagery showed a bridge still under construction. We added a more recent local raster file of the same bridge, now completed, and used the swipe tool to examine both during the demonstration. Here's a screen shot from that demonstration showing the bridge in the default map on the left, still under construction, and the newer local raster file with the bridge completed on the right.

If we visit that same area now we'll see that the Explorer default map has been updated, and shows the now-completed bridge.

The imagery in Explorer's default map is updated quarterly, and you may have noticed some other updates to the cartography in the Topo, Boundaries & Places, and Streets services. You can learn more about services on the ArcGIS Online Resource Center by visiting the Directory of Services. Select one and click to learn more about its source(s), update frequency, and more.

Updates and changes are also posted on the ArcGIS Online Services Blog.