WorldWide Telescope

WorldWide Telescope Brings Space Exploration to Earth.
A service free of charge from Microsoft lets students and lifelong learners tour the night sky using high-resolution images from the world’s best land- and space-based telescopes.

Want to see the same images that scientists at NASA use for their research or perform your own research with those images? Or do you want to see the Earth from the same perspective that astronauts see as they descend to Earth? How about taking a 5 minute break and viewing a panorama of a different city? Install WWT and start your explorations.

More: http://www.microsoft.com/presspass/press/2008/may08/05-12WWTPR.mspx
Download : http://content.worldwidetelescope.org/update/wwtsetup.msi

WorldWide Telescope minimum system requirements

For PC:

* Microsoft® XP SP2 (minimum), Windows® Vista® (recommended)
* PC with Intel Core 2 Duo processor with 2 gigahertz (GHz) or faster, recommended
* 1 gigabyte (GB) of RAM; 2 GB RAM recommended
* 3D accelerated card with 128 megabytes (MB) RAM; discrete graphics card with 256-MB VRAM recommended for higher performance
* 1 GB of available hard disk space; 10 GB recommended for off-line features and higher performance browsing
* XGA (1024 x 768) or higher resolution monitor
* Microsoft Mouse or compatible pointing and scrolling device
* Microsoft® DirectX® version 9.0c and .NET Framework 2.0
* Required for some features; Internet connection at 56 Kbps or higher through either an Internet service provider (ISP) or a network. Internet access might require a separate fee to an ISP; local or long-distance telephone charges might also apply

Estimated download time 1 hour (56Kb), 10 minutes (DSL 512Kb)