Planetary Defense is a space strategy game where you take charge of a planets defenses against waves of attacking aliens. Defend against missiles, multiple warhead rockets, cloaked starships, meteors, homing missiles and laser-armed satellites. Some of the 21 missions include orbiting moons complete with colonies, defensive shield grids, radar bases and evacuating starships. Superb graphics and low system requirements, only a 3MB download.

• License: Shareware
• Language: English, Spanish, French, German, Italian
• Release: 2003-01-14
• Size: 2 Mb
• Cost: 19.95 $

Planetary Dreamscapes 1 Featuring eleven amazing scenes to choose from, six musical compositions to set the mood, blazing stars, swirling nebula, and galactic vista await you as we bring you spectacular images from deep space, both real and imagined.

• License: Shareware
• Language: English
• Release: 2003-10-20
• Size: 2 Mb
• Cost: 5.00 $

Real stars and galaxies in 3D and full color. Move and look in any direction. Easy to use with keyboard shortcuts and presets. 9,000 stars (all visible stars, plus lots of nearby dim stars) and 2,400 galaxies. Displays known planetary star systems. Find stars and galaxies by name and fly to them with a keypress. Select stars by magnitude, distance, or spectral type. Select galaxies by distance or group. Has an outline of our galaxy.

• License: Shareware
• Language: English
• Release: 2002-03-15
• Size: 1 Mb
• Cost: 5.00 $

Alcyone Ephemeris is an accurate and fast astronomical ephemeris calculator covering the period 3000 BC to AD 3000. It calculates heliocentric, geocentric, and topocentric positions of the Sun (Earth), Moon, planets, small bodies (asteroids, comets), and fixed stars in ecliptical, equatorial, and horizontal coordinates (including angular differences between two bodies), with optional corrections for parallax and refraction.

• License: Shareware
• Language: English
• Release: 2008-01-30
• Size: 51 Mb
• Cost: 49.00 $

AstroGrav is astronomy software that allows you to simulate how astronomical objects move and interact under the force of gravity. It features superb interactive 3D graphics which allow you to move around within a many-body astronomical system, while watching how it evolves with the passage of time. A wide variety of sample files are provided, and comprehensive editing facilities allow you to create and modify your own astronomical systems.

• License: Shareware
• Language: English
• Release: 2006-09-18
• Size: 20 Mb
• Cost: 79.00 $