The femur connects to the knee at one end and fits into the hip socket at the other. It's the longest bone in many other mammals as well.

A perfect reflector such as a mirror would have an albedo of 100, the moon has an albedo of 7, and the Earth has an albedo of 36.

The barycenter is the center of mass of two or more bodies that are orbiting each other, or the point around which they both orbit. It is an important concept in fields such as astronomy and astrophysics.

There are five metacarpal bones in each hand that connect your fingers to your wrists.

The coma is the nebulous envelope around the nucleus of a comet. It is formed when the comet passes close to the Sun on its highly elliptical orbit; as the comet warms, parts of it sublime.

A parsec is a unit of length used to measure large distances to objects outside our Solar System. One parsec is equal to about 3.26 light-years (31 trillion kilometres or 19 trillion miles) in length.

The orbital cavity contains the eyeball and its associated muscles, vessels, and nerves.

Herpetology (from the Greek meaning "to creep") is the branch of zoology concerned with the study of amphibians and reptiles.

Although English Scientist Robert Hooke described a honeycomb-like network of cellulae (Latin for little storage rooms) in cork slice using his primitive compound microscope, the first man to clearly observe a live cell under a microscope was Anton van Leeuwenhoek, who in 1674 described the algae Spirogyra.

Forensic scientists collect, preserve, and analyze scientific evidence during the course of an investigation. While some forensic scientists travel to the scene to collect the evidence themselves, others work from a laboratory, performing analysis on objects brought to them by other investigators.