This is an advanced application for the Palm that gives you a great insight into the sky above.

It can be used to plot a sky map for any time and geographical position, complete with all 88 constellations and the correct position of the sun, moon, planets, 9,000 stars and hundreds of space objects, comets and asteroids.

It is perfect for locating a particular object in the night sky. Read the co-ordinates of any object from Planetarium to set a telescope's compass rings; connect your Palm to a digital telescope and this can be done automatically.

A huge amount of calculations can be carried out including twilight times, moon phases, rise- and set-times of all planets, and the co-ordinates, magnitude and distance of any object in the sky.

A time-increment feature lets you step forwards or backwards in time to follow the path of a particular planet, including details of retrograde motion and conjunctions.

It claims accuracy of 0.1 degrees and, with a database of 600 major cities, it is useful worldwide.

Purchase price: $24