Do you want your kids visualize and grasp knowledge on our Solar System? Or do you want make a virtual tour of universe and see all celestial objects just like sitting and watching from a window seat of a space ship?
Then, Celestia which is an open source free software will be the right choice for you.
Celestia contains data gathered by the European Space Agency including imagery, telemetry and positional data for planets, asteroid and stars and then maps it in 3D.
The objects in Celestia are moving along their true paths, synchronized to your computer's time and date. To see this in action, you can speed up time, using increase real time by 10 times, 100 times, 1000 times and more and enjoy planets and seeing revolve themselves and in an orbit, you can watch shadows move around planetary bodies, moons fly through their orbit or follow an asteroid on its journey through space.
The following video will teach you the basic operations in Celestia once you downloaded, installed and launched the same.
Celestia is a unique space simulation program for the PC that lets you and your kids interactively leave your seats at home and experience our universe in stunning three dimensions. It is capable of taking you nooks and corner of our solar system as well as deep into space to perform a virtual tour of our space.
You can personally orbit Mars, plunge through the rings of Saturn or travel anywhere in the Solar System and beyond into deep space, at any speed, in any direction you choose, and at any time in history.
If desired, you can visit stars or nebula circling the Milky Way or view thousands of other galaxies and galactic clusters from intergalactic space. You can travel back in time to fly alongside famous spacecraft like Sputnik or Voyager as they make history. You can try docking with the International Space Station. You can even travel five billion years into the future to witness the death of our Sun and of Earth.
Many space enthusiasts have acknowledged that Celestia is a very accurate program. It depicts the Solar System of planets, dwarf planets, moons, asteroids, comets and spacecraft in vivid detail, and can draw and track over 2 million stars and 10,000 galaxies in real time and proper position. It can also create rotating stars, planet atmospheres, planet shine on other objects, drifting clouds, moving surface shadows, reflections off oceans and ice, magnetic fields, constellations, solar eclipses, speeding comet tails, erupting solar flares and swirling nebula gas. Its add-on database includes over 50 real spacecraft and dozens of fictional ones.
Celestia is in use in millions of locations worldwide, and is routinely used by high schools, universities, NASA, SÃO and other government space agencies. It has also been employed in movies and in TV shows. Celestia was created and is provided open source, free of charge by Mr. Chris Laurel and the Celestia Development group, a collection of space enthusiast professionals who have donated their talent to bring it to the rest of the world.
The following link will provide an in-depth installation tutorial with lot of astronomical resources.
This is one of the useful tutorials to operate Celestia
Those who are interested to use Celestia as an educational aid more resources are available in the following link.
And finally before wrapping up, have a look at this video that is shot based on motion of a computer screen when Celestia program is in use. This is the screen-shot that mainly captured various natural special effects while celestial bodies function in the universe. Of course capturing of the scenes that show motion of heavenly bodies may require increase of real time by 1000 times are more. (Tip: You can easily adjust the real time in Celestia, using Time menu on the top)
Source: Celestia Website