The Virtual Telescope Project 2.0: Home. Discovery Space. Planet Impact: Home. Einstein's Big Idea. One of Albert Einstein's greatest insights was realizing that time is relative.
It speeds up or slows down depending on how fast one thing is moving relative to something else. How much does it change? In this feature originally designed for students in 1996, "Captain Ein" and "Major Stein" have volunteered to help you find out. Send Captain Ein on a round-trip journey to a star and then compare her age with Major Stein's on Earth. Index of /info/Science/Space & Time. HubbleSite - Out of the ordinary...out of this world. Fun Space Facts for Kids - Cool, Moon, Planets, Sun, Crazy, Interesting Astronomy Information.
Astronomy Picture of the Day Archive. Planetarium - Interactive star map and virtual sky. Planetary Fact Sheet - Ratio to Earth. Planetary Fact Sheet - Ratio to Earth Values * - See the Fact Sheet Notes.
Planetary Fact Sheet in Metric Units Planetary Fact Sheet in U.S. Units.