No other planet has intrigued humans as much as Mars has. For over 130
years, storytellers have been going back to Mars for inspiration. In most of those
stories, there's either a civilisation on Mars, often bent on conquering our
planet, or we colonize Mars sometime in the future. The stories started when
astronomers observed canals on Martian surface, which some interpreted as an
irrigation system of an advanced civilisation that was able to transport the
water from melting polar ice caps all the way to the equator.
Mars. Credit: NASA
Today we know there is no intelligent life on Mars, unless they are hiding underground. There are strong indications that there is water on Mars, although not in liquid state, but as ice in the polar caps and possibly underground. This gives us hope that there is still some simple form of life on the planet. Or at least that there once was.
Martian surface is very interesting because it gives strong indications that there was once liquid water covering it, with oceans, rivers and lakes. This was 3.5 billion years ago though, so it is most likely that even if there was life on Mars, it didn't have time to develop enough to have intelligence. The red colour because of which Mars gained the nickname Red Planet is caused by its surface contains lots of iron oxide i.e. rust.
Mars if it was terraformed. Credit: NASA
Speaking of surface, two fascinating things that everyone should know about Mars are Olympus Mons and Valles Marineris. The former is Martian volcano which is 26 kilometers high, making it the tallest mountain in the Solar System. The latter is a system of canyons, over 4000 kilometers long, 200 km wide and 7 km deep.
Valles Marineris on Mars. Credit: NASA
Today, Mars is a desert with large dust storms. Its atmosphere is very thin, with surface pressure over 130 times lower than that on Earth. It is tilted along its axis, some 25 degrees, so it has seasons just like Earth, except they last twice as long since it takes 687 Earth days for Mars to circle the Sun. One day on Mars lasts only a bit longer than our day – 24 hours, 39 minutes and 35 seconds.
You can check for more numbers in the column on the right. However, it is worth mentioning that Mars is about 10 times lighter than Earth, resulting in its gravity equaling only 37.5% of what we feel here on Earth. Mars is half the size of our home planet.
There were over 50 missions to Mars, since it is "only" 78 million kilometers away from Earth. Currently, we are getting some very valuable data from NASA's Curiosity rover. Also, worth mentioning is that there are couple of manned missions being planned, most notably Mars One which wants to send first colonists to Mars by 2022. Apparently over 165,000 people have applied with the applications ending August 31, 2013. It is a one way trip, mind you!
Mars has two moons, Phobos and Deimos, which are only 27 and 15 kilometers in diameter respectively. Since Phobos is only 6000 kilometers away from Martian surface, in less than 10 million years it will collide with Mars, possibly creating a rocky ring around the planet before that and after it has been torn apart by planet's gravity!
Phobos, larger of the two Martian moons. Credit: NASA