Aciqra (uh-SEE-kruh) is a free and open source virtual planetarium and sky mapping program which tracks celestial bodies including planets, deep sky objects and stars to an accuracy of a fraction of a degree for thousands of years into both the future and the past. More information is available on SourceForge...

Features:

Tycho-2 star catalog w/ 2.5 million stars

Full NGC and IC catalogs w/ 13000 deep space objects

Interface designed for efficiency

Correction for atmospheric refraction

Night vision mode

Correction for nutation and precession

Calculate proper motions for stars

Selecting objects to show details

Constellation boundaries

Save current view as an image

Angle indicator (simulates views from an eyepiece)

Comets and asteroids tracking

Earth's umbra and penumbra for lunar eclipse simulations

New release finder and downloader