Best Free Sky Simulator

Home Planet, a comprehensive astronomy / space / satellite-tracking package for Microsoft Windows 95/98/Me and Windows NT 4.0/2000/XP and above, is now available; see details at the end on how to download and install the software. 

Release 3.3a of Home Planet is a native 32-bit Windows application which cannot be used on Windows 3.1; if you have such a system, download Home Planet Release 2, which remains available. 

Home Planet is in the public domain; it is free software. It is not shareware—you don't have to register it or pay anybody anything, and the version you download is fully functional as soon as you install it. You are free to give copies to your friends, post it on other sites, and otherwise use and distribute it in any way without permission, restriction, attribution, or compensation of any kind.

Link: Download Home Planet

Free WorldWide Telescope Online

 

The WorldWide Telescope (WWT) is a Web 2.0 visualization software environment that enables your computer to function as a virtual telescope—bringing together imagery from the best ground and space-based telescopes in the world for a seamless exploration of the universe.

WorldWide Telescope is created with the Microsoft® high performance Visual Experience Engine™ and allows seamless panning and zooming around the night sky, planets, and image environments. View the sky from multiple wavelengths: See the x-ray view of the sky and zoom into bright radiation clouds, and then crossfade into the visible light view and discover the cloud remnants of a supernova explosion from a thousand years ago.

In celebration of the International Year of Astronomy, WWT is now available with a localized user-interface in several languages.

Link: WorldWide Telescope

The Best Online Planetarium

Flash Planetarium Project produces the best online planetarium available, allowing you to view the night sky from anywhere in the world from within your browser.

If you've a passing interest in Astronomy or you're are an enthusiastic amateur astronomer or science buff, then we're sure that you'll find this site interesting and above all, fun!

Features:

View all 88 Constellations;

Accurate Planetary Positions;

View the sky from your location;

100,000 star database;

View the sky at ANY time and date

... and much more to come!

Link: Online Planetarium 

Solar System and Astronomy Model Simulator

Solar System 3D Simulator is a FREE software application that generates a realistic solar system model and planets in 3 Dimension on the PC using advanced physics formulas.

It can display the planets and their orbits, the sun and the moon. The nine planets including planet earth and their detailed physical and chemical information and image pictures are also displayed including solar power, solar energy and solar eclipse details.

The software is easy to use with a fully Windows based interface. The program has a fully graphical menu oriented interface designed for ease of use. The Solar System 3D software has been designed for fast setup and interactivity with excellent high quality visual output. The software runs on all Windows Operating Systems.

Link: download Solar System 3D Simulator

Astronomy Screensaver from NASA

Astronomy 2005 screensaver, a compilation of stunning images, collected by Robert Gregory Garfinkle  from N.A.S.A. (National Aeronautics and Space Administration).

This high-resolution collection includes images taken from the Hubble Space Telescope (S.T.S.C.I.), Manned / Unmanned missions such as the Apollo Lunar Missions, the Mars Global Surveyer (Orbital), Mars Rovers (Land-based), Cassini / Huygens (Saturn and it´s satellites), and other breathtaking studies and adventures.
All Images are courtesy of N.A.S.A.

Link: download free screensaver Astronomy

Open source virtual planetarium

Aciqra, open source virtual planetarium and sky map program. It has the ability to track nearly 120,000 stars, the 8 planets, all 109 Messier object, the sun and the moon from any location on Earth to an accuracy of 1 degree for the next 50 years. It also includes a wealth of built-in tools called "widgets" which include a solar system viewer, an eclipse/transit predictor and a conjunction engine.

The Aciqra project is the world's largest and most active open source GDI-based planetarium available on the internet. This reflects the tremendous amount of energy and the hundreds of hours of work put towards creating and perfecting it.

Link: Aciqra

Neave Planetarium Online

 

Neave Planetarium is an online virtual planetarium of stars and planets customizable by location (latitude and longitude) and time of day. Get the correct view for your sky by setting your position on the world map in the Location menu on the right-hand side. The default location is London, England, but you can move the crosshairs on the map to view the sky from any point on Earth.

Users can move around the sky, adjusting both the time and viewing location, which can be changed to anywhere in the world. Pointing at a certain star or planet reveals its name, constellation, brightness, and its distance in light years from Earth.

Click the sky to start or stop moving around. As you move your mouse, your view will change. Pointing at a star will reveal its name, its constellation, its magnitude and its distance. You can also use the arrow keys to change the view.

Link: Neave Planetarium

Celestia the free space simulation

 

Celestia, Open Source, real-time space simulation that lets you experience our universe in three dimensions. Unlike most planetarium software, detailed model of the solar system, over 100,000 stars, more than 10,000 galaxies, and an extension mechanism for adding more objects.

All travel 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.
 
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.

Link: download Celestia