The orbit of a planet is an ellipse with the Sun at one focus. What this law means is that the further you are from the Sun, the longer it takes to orbit it. The distance that light travels in one year, equal to 10,000,000,000,000 km, or 63,000 AU . Macho is short for MAssive Compact Halo Object.
Machos are the only type of dark matter for which there is direct evidence.
The fourth planet from the Sun, Mars is a terrestrial planet . Mars is smaller than Earth, and is sometimes called the red planet. Check out SEDS' Nine Planets , for more about Mars. Or see StarDate's Solar System Guide . With an orbit of only 58 million km, Mercury is the closest planet to the Sun.