Planetarium Software for Young Children in Ubuntu / Debian Linux : Stellarium

Stellarium is a free open source planetarium Software for your computer. It shows a realistic sky in 3D, just like what you see with the naked eye, binoculars or a telescope.
Features

• default catalogue of over 600,000 stars
• extra catalogues with more than 210 million stars
• realistic Milky Way 
• Drawing of the 88 constellations with their names
• Drawing of more than 40 messiers objects (Orion, M31 etc..)
• very realistic atmosphere, sunrise and sunset
• the planets and their satellites
• a powerful zoom, time control
• telescope control
• eclipse simulation 

Available in Windows, Mac and Linux Platform
How to Install Stellarium in Ubuntu / Debian Linux
Open a terminal

$ sudo apt-get install Stellarium 

Or Use Synaptic Package Manager 

Letters and Numbers Learning Game for Kids in Ubuntu Linux : lletters

GTK letters-learning game for small children . It is specialy made for  children 2 and up, and is a learn with  fun game. It helps younger children learn their letters and numbers, while older children will improve their spelling, and vocabulary skills. It will also helps your kids to develop important keyboard and mouse skills too.

Open a Terminal and type

$ sudo apt-get install lletters

or use Synaptic Package manager