The Red Planet
Mars is the fourth planet of the solar system, which means it is a terrestial planet, and the last terrestial planet of the solar system. It is about 1.524 AU. It has a mass of 6.39 * 10^23 kg, and takes 687 days to complete a full orbit around the Sun. It was discovered by Galileo Galilei in 1610. It's atmosphere contains 95.97% carbon dioxide, 1.93% argon, 1.89% nitrogen, and traces of other elements like oxygen, and other substances like carbon monoxide.
Mars' physical features include a red appearance, and that redness is as bright as Sirius (the brightest star) when is opposite of the Sun.
The core of Mars is similar to Earth, with iron-nickel alloy, and the mantle is made up of silicate.