Space Facts

Space and Astronomical Science

If there is a subject you cannot find here, please let us know by clicking on the "Contact Us" button at left.

Astronomy, General

What are the differences between stars, planets, and moons?
What kinds of star catalogs are there?

Astronomy, Measures

How old are the stars?
What is Fe/H?
What does star magnitude (visual, absolute, bolometric) mean?
What is the difference between parsec and light year?
What do spectral type and luminosity class mean?
How big is an Astronomical Unit?
What is precession of the equinoxes?
How do astronomers measure the position of stars in our night sky?

Astronomy, Solar System

The Solar System Planets

Astrophysics

Star Life Cycle, including a chart of Main Sequence ages.

Mass and Gravity

What is mass?

Mathematics

What are logrithms and exponents, and how are they used?

Stellar Identities

What are the names of the stars?
What are the names of nearby stars?
How many star catalogs are there?
How can you have more than one star in a system?
What is the ADS catalog?
What is the DM catalog?
What does Flamsteed-Bayer mean?
What is the Gliese catalog?
What is the HD catalog?
What is the HIP catalog?
What is the HR catalog?
What is the MSDB catalog?
What is the SAO catalog?