Celestia Portable 1.6.1 is a full planetarium packaged as a portable app, so you can view the universe in 3-D anywhere. This release updates Celestia to the latest version and has an improved launcher and installer. It's packaged in PortableApps.com Format so it can easily integrate with the PortableApps.com Suite. It supports upgrades by installing right over an existing copy, preserving all settings. And it's open source and completely free.

Celestia - a free three-dimensional astronomical program, created in the programming language C++, for the platforms Microsoft Windows, Linux and Mac OS X. Created by Chris Laurel and is available under the GNU General Public License.

The program, based on the catalog HIPPARCOS, allows the user to view objects ranging in size from artificial satellites to complete the galaxies in three dimensions using technology of OpenGL. Unlike most other virtual planetarium, a user can freely travel through the universe.

Unlike most planetarium software, Celestia doesn't confine you to the surface of the Earth. You can travel throughout the solar system, to any of over 100,000 stars, or even beyond the galaxy. All movement in Celestia is seamless; the exponential zoom feature lets you explore space across a huge range of scales, from galaxy clusters down to spacecraft only a few meters across. A 'point-and-goto' interface makes it simple to navigate through the universe to the object you want to visit. Celestia is expandable. Celestia comes with a large catalog of stars, galaxies, planets, moons, asteroids, comets, and spacecraft. If that's not enough, you can download dozens of easy to install add-ons with more objects.

Celestia is expandable. Celestia comes with a large catalog of stars, galaxies, planets, moons, asteroids, comets, and spacecraft. If that's not enough, you can download dozens of easy to install add-ons with more objects.