Motherplanet Earth Explorer review

Earth Explorer uses satellite data to present an intimate view of the entire planet, complete with borders, cities, rivers and a mass of other information.

Backed by an extensive online database, not only is this a serious educational resource, it's also a fascinating diversion.

The software allows you to zoom into a model globe rendered at a resolution of 1km per pixel. Zoom into the Amazon delta and you'll see ugly strip-farming scars snaking through the jungle. Hover over Egypt and you'll see the lush banks of the Nile meandering through the desert and into the Mediterranean.

The full download is 96MB of compressed geographical information. You can just download the software without the database, which is only 4.36MB and costs $30 (around £17). Using this version, as you zoom in, an online database fills in detail on the 1km scale. The database uses a clever caching mechanism to ensure the program accesses the online database as efficiently as possible over a dial-up connection, but naturally you'll get faster results with broadband.

Earth Explorer also provides current information on 267 countries and regions, 15,000 islands, 40,000 cities and 1,700 earthquakes, all of which it presents in a list panel with plenty of Sort By options. Locating Bam in Iran, for instance, provides statistics and a large amount of technical information about December 2003's devastating earthquake, and links to reports on the event. The list panel also provides details such as country and city population and its sortable nature makes it easy to look up, say, the largest island.

As well as scrolling over the planet's surface, Earth Explorer enables you to drag the current view around and centre on the cursor, which is handy when you want to zoom accurately into an area. A measurement tool allows you to select a point and drag a ruler over the Earth's surface to measure distance.

It would be nice to be able to control the scroll speed, especially at high magnification. The colours, fonts and lines are not configurable, either, which is confusing at low magnification. You can turn cities on or off, but it would have been useful to filter their display by, say, population so that the globe doesn't look like a Christmas tree when you zoom out. These are minor criticisms, however.

What really strikes you as the Earth scrolls majestically by is what a big planet this is and how peaceful it seems from space. A look at the troubled Holy Land region, for instance, reveals a gigantic bay area flanked by mountains, desert and a deep blue sea. Earth Explorer can't quite match up to a sightseeing trip on the space shuttle, but it's the closest any of us will probably get, and it's an absorbing and educational piece of software.