In a previous Web 2.0 Weekly, I wrote about one of the many overlays for Google Earth.  In particular, we looked at an overlay that provided Google Earth data for every geographical location mention in the Bible.  I spent a bit of that review talking about some aspects of Google Earth itself, but I recently realized I haven’t actually done a full review of Google Earth.  I feel a bit ashamed about that, because Google Earth is an incredibly powerful tool that can be used in just about any course, not just history or the social sciences.  Even better, Google Earth is free to download and use.

Google Earth can be downloaded for Windows 2000 and up, Mac OS X 10.4 and up (PowerPC G4/G5 or Intel), and Linux with kernel 2.4 or later (only Ubuntu and Red Hat are officially supported).  What all of this means is that most computers made in the last 10 years or so that you’re likely to encounter at home or school are capable or running Google Earth to some degree.  Google Earth also requires an active connection to the Internet and this is definitely a case where a faster connection is better.

Performance in Google Earth can vary based on the number of overlays, layers, and other features you have enabled.  It is also highly dependent on the speed of your Internet connection, because Google Earth downloads much of what it displays as it is needed.  This is especially noticeable when zooming in on an area especially if you have many layers or the 3D features enabled.

If you want to use Google Earth in your classroom, I highly recommend using a digital projector or another large display that can be seen by everyone in the room.  Google Earth also works exceptionally well with interactive whiteboards.

So, what can you use Google Earth for?  Google Earth is a great way to expose students to geography and historic locations.  For example, below is a screenshot I took of the Giza complex in Egypt (click the image to see the full size).

In the above image, you can see several Google Earth features, most noticeably, the 3D pyramids and Great Sphinx.  These are part of the 3D buildings option.  You can also clearly see the topography of the area, due to the “elevation exaggeration” feature.  Basically, Google Earth can be set to overemphasize elevation changes to highlight topography.  You might also notice the little yellow boxes in the image.  Clicking on those in the Google Earth program will open up a comment window that contains basic information about a feature in the current view.  This can be images from one of several communities, web links, etc.  Google Earth also includes a basic “mini-browser” that will allow you to follow links without leaving Google Earth.

Another great Google Earth activity is asking students to take a look at their communities.  Here’s what Rockford, Illinois looks like from 17 miles up.

In this image, I have just enough information displayed to provide some basic landmarks without cluttering the image too much.  The green outlines are area parks and nature preserves.  Students will likely find it interesting to discover just how much of what humans have built can be seen from a great height.  It’s also interesting to be able to see how spread out their community might be.  In the case of this image, I increased the apparent altitude until I could see all of the city and its suburbs.

The above examples are likely best suited for history or social studies classes, but what about other courses?  An friend of mine who teaches English suggested the following idea.  Pick a location in Google Earth like the Eiffel Tower (the Eiffel Tower area actually has some of the highest resolution images in Google Earth) and then ask students to describe what they see around it.  This is best done as a thought exercise, asking students to imagine themselves in the given location.  This can be an excellent way to practice reading and storytelling skills by working on describing setting and atmosphere.

A handy feature for the science or math class is the ruler.  In Google Earth, you can measure both a distance and heading from one location to another.  You can also use the ruler to measure the distance of a path.

Google Earth also allows the user to explore things besides the planet Earth.  Clicking one button takes you to a view of the sky above your current map location.

And just as with the Google Earth view, there are numerous overlays and layers available in the Sky view.

You can similarly visit both the Moon and Mars from Google Earth.  The program even contains a basic flight simulator.

So far, we’ve just barely scratched the surface of what Google Earth can do.  I highly recommend that if you are interested in using it in your class, you block out a few hours to experiment with all of the features of this amazing program.  I also think that we’ll be taking a look at some of the other features of Google Earth in an upcoming Web 2.0 Weekly.

One of the best things about Google Earth is the communities that have grown up around it.  The Keyhole.com site is just one of many such communities that is devoted to locating and analyzing interesting places in Google Earth.