What Is a Comet, and What Is It Made Of?
A comet can appear from nowhere, hang in the sky for weeks with a glowing tail, and then vanish for a thousand years. These icy wanderers are leftovers from the birth of the solar system. Here is what a comet is and how it works.
What Is a Galaxy, and How Many Are There?
A galaxy is a city of stars, held together by gravity and adrift in a universe that holds hundreds of billions more like it. Ours is just one. Here is what a galaxy actually is, and how astronomers count them.
How Does Compound Interest Work, and Why It Matters
Compound interest is often called the closest thing to free money, and also the reason credit card debt spirals. It is the same force, working for you or against you. Here is how it actually works.
What Is a Credit Score, and How Is It Calculated?
A three-digit number decides whether you get the loan, the apartment, or the low interest rate. Here is what a credit score is, how it is calculated, and how to move it up.