Mars is the fourth planet from the Sun and is the second smallest planet in the solar system. Named after the Roman god of war, Mars is also often described as the “Red Planet” due to its reddish appearance. Mars is a terrestrial planet with a thin atmosphere composed primarily of carbon dioxide.
1. It was believed life existed on Mars for much of the nineteenth century. The reason behind this belief was part mistake and part imagination.
2. In 1877, the astronomer Giovanni Schiaparelli observed what he believed to be straight lines on Mars’ surface. As others noticed these lines, some suggested that they were too straight and could only be the work of intelligent life. The popular conclusion as to the nature of these lines was that they were canals constructed for irrigation purposes.
3. However, with the development of more powerful telescopes in the early twentieth century, astronomers were able to view the Martian surface more clearly and determine that these straight lines were merely an optical illusion. As a result, the earlier claims of life on Mars were without evidence and, therefore, discarded.
4. Mars is the most hospitable planet for life other than the Earth.
5. The Viking mission in the 1970s conducted experiments on the Martian soil in hopes of detecting microorganisms. While it was initially believed that the formation of compounds during the experiments were a result of biological agents, it has since been determined that these compounds can be created without biological mechanisms.
6. The composition of Mars’ atmosphere is extremely similar to Venus’, one of the least hospitable atmospheres in all of the Solar System. The main component in both atmospheres is carbon dioxide (95% for Mars, 97% for Venus), yet a runaway greenhouse effect has taken hold of Venus, producing temperatures in excess of 480° C, while temperatures on Mars never exceed 20° C.
7. Even though the results lean toward the absence of life on Mars, scientists have speculated that conditions are right for life to exist beneath the planet’s surface.
8. Mars has a very thin atmosphere. The resulting atmospheric pressure is only about 1% of that found at sea level on Earth. That is the equivalent pressure found at 35 km above the Earth’s surface.
9. Mars is the fourth planet from the Sun and last of the terrestrial planets and is around 227,940,000 km from the Sun.
10. The planet is named after Mars, the Roman god of war. It was known to the ancient Greeks as Ares, their god of war. This is thought to be because of the blood-red color of the planet which was also used by other ancient cultures.
11. The landmass of Mars and Earth is very similar. Despite Mars being just 15% the volume and 10% the mass of Earth, it actually has a similar landmass because water covers about 70% of Earth’s surface.
12. Only 16 of the 39 Mars missions have been successful. Beginning with the USSR’s Marsnik 1 which was launched in 1960, 39 orbiters, landers and rovers have been to Mars but only 16 of those missions were a success.
13. Pieces of Mars have been found on Earth. It is believed that trace amounts of the Martian atmosphere were within meteorites that the planet ejected. These meteorites then orbited the solar system for millions of years amongst the other objects and solar debris before eventually entering the Earth’s atmosphere and crashing to the ground.
14. Mars does not have a magnetic field but there are some scientists that believe it did have a magnetic field somewhere around 4 billion years ago.
15. The tallest mountain known in the solar system is on Mars. Olympus Mons is a 21 km high and 600 km diameter shield volcano that was formed billions of years ago. Scientists have found a lot of recent evidence of volcanic lava which suggests Olympus Mons may still be active. It is the second highest mountain in the entire solar system, topped only by the Rheasilvia central peak on the asteroid Vesta, which is 22 km high.
16. Mars experiences huge dust storms – the largest in our solar system due to the elliptical shape of the planet’s orbit path around the Sun.
17. The Sun looks about half its size half it does from Earth when seen from Mars. When Mars is closest to the Sun in its orbit the southern hemisphere points toward the Sun and this causes a very short but fiercely hot summer. In the north it experiences a brief but cold winter. When the planet is farthest from the Sun, Mars experiences a long and mild summer because the northern hemisphere points toward the Sun. This is compared with a cold and lengthy winter in the south.
18. It takes Mars 687 Earth days to orbit the Sun with its orbit radius of 227,840,000 km.
19. Mars has seasons like Earth, but they last twice as long. This is because Mars is tilted on its axis by about 25.19 degrees, which is similar to the axial tilt of the Earth (22.5 degrees).
20. The orbit of Mars is the most eccentric of the eight planets. This means it is the least circular orbit path of the planets.