If you're new to SkySafari, this is basic version. It includes everything you need to get started learning the night sky: 120,000 stars; over 200 star clusters, nebulae, and galaxies; all major planets and moons, and dozens of asteroids, comets, and satellites - including the ISS.
Here's what you can do with SkySafari 4:
Simulate the night sky from anywhere on planet Earth, up to 100 years in the past or future. Animate transits, conjunctions, eclipses, and other events with SkySafari's Time controls. Explore the sky with Night Vision turned on, and preserve your eyesight after dark.
Learn the history, mythology, and science of the heavens from SkySafari's hundreds of object descriptions. Browse hundreds of astronomical photographs and NASA spacecraft images.
SkySafari takes advantage of Apple's latest Mac OS X features. It understands multitouch gestures and supports full-screen mode. Its responsive, fluid interface borrows from the best of SkySafari for iOS. SkySafari for Mac OS X truly brings astronomy software into the 21st century. It's more than just a star chart - it's your celestial travel guide!
All this is built into SkySafari 4 - you don't need an internet connection to use it. SkySafari 4 Plus and Pro add even more - but the basic version is everything the casual stargazer will ever want. (Please note: there is no discount upgrade path to SkySafari 4 Plus or Pro.)