ArcGIS Online is tremendous resource of ready-to-use map and globe services that can be accessed directly using ArcGIS Explorer. Explorer's default globe and the additional maps and layers that you add from the Data tab on the Explorer Resource Center are all powered by ArcGIS Online.

You can also connect directly to ArcGIS Online and discover additional services not currently included on the Explorer Resource Center. Here's how...

First, make a direct connection to ArcGIS Online. From Explorer choose File > Open, then click Servers. Create a new connection by choosing ArcGIS Server.

 Enter the URL to ArcGIS Online. Note that in the graphic below the final "s" is cut off in the input box. The complete URL should be http://services.arcgisonline.com/arcgis/services. You don't need a user name or password.

Once you've established the connection, you'll see something like this - the list of all available data services from ArcGIS Online.

If you look closely you'll note the different icons that distinguish and organize what is available.

When you first connect globe services will be a little faster to draw since these don't need to be projected and most are already cached. Map services will take just a little bit longer to display when you first connect, but will be just as fast once you've connected and generated local cache.

To add a service just double-click. Here we've chosen to open a NASA cloud cover service. Try adding one or both of the layers in the service.

Now that you know how to add ArcGIS Online services directly, we'll take a closer look at others in upcoming posts.