I have a feeling I am not the only one interested in Curiosity's imminent touchdown on Mars later tonight! I was worried that people might not even notice because of the enormous spotlight on the olympics but in reality the world seems to be waiting with bathed breath. There is still hope for our species! ;)
So what's the deal? What's so interesting about a rusty ball of rock floating through space? Fool! Would you say earth is just a watery rock floating through space? Have some respect would you! ;) Mars is another world, an entire planet waiting for exploration. Large parts of its history have yet to be uncovered and its future will intertwine with that of mankind. Mars is the scene for one of the greatest genuine adventure stories in mankind's future history. Another great leap waiting to happen.
Mars is a terrestrial planet that consists of minerals containing silicon and oxygen, metals, and other elements that typically make up rock. Like Earth, this planet has undergone differentiation, resulting in a dense, metallic core region overlaid by less dense materials. Current models of the planet's interior imply a core region about 1790 km in radius, consisting primarily of iron, nickel and sulfur. Two of its most striking geological features are the Valles Marineris, a 4,000 km long, 200 km wide and 7 km deep system of canyons that runs along the Martian surface east of the Tharsis region and the Olympus Mons, a towering shield volcano that reaches a mind boggling 27 km into the sky, more than 3 times the height of Mt Everest. It is the highest known mountain on any planet within our Solar System.
Although Mars has no evidence of a current structured global magnetic field, observations show that parts of the planet's crust have been magnetized, and that alternating polarity reversals of its dipole field have occurred in the past. This paleomagnetism of magnetically susceptible minerals has properties that are very similar to the alternating bands found on the ocean floors of Earth. One theory, published in 1999 and re-examined in October 2005 (with the help of the Mars Global Surveyor), is that these bands demonstrate plate tectonics on Mars four billion years ago, before the planetary dynamo ceased to function and the planet's magnetic field faded away.
During the Solar System's formation, Mars was created as the result of a stochastic process of run-away accretion out of the protoplanetary disk that orbited the Sun. Mars has many distinctive chemical features caused by its position in the Solar System. Elements with comparatively low boiling points such as chlorine, phosphorus and sulphur are much more common on Mars than Earth; these elements were probably removed from areas closer to the Sun by the young star's energetic solar wind.
After the formation of the planets, all were subjected to the so-called "Late Heavy Bombardment". About 60% of the surface of Mars shows a record of impacts from that era, while much of the remaining surface is probably underlain by immense impact basins caused by those events. There is evidence of an enormous impact basin in the northern hemisphere of Mars, spanning 10,600 km by 8,500 km, the largest impact basin yet discovered. This suggests that Mars was struck by a Pluto-sized body about four billion years ago. The event created the smooth Borealis basin that covers 40% of the planet.
geological evidence gathered by unmanned missions suggest that Mars once had large-scale water coverage on its surface. In 2005, radar data revealed the presence of large quantities of water ice at the poles, and at mid-latitudes. The Mars rover Spirit sampled chemical compounds containing water molecules in March 2007 and the Phoenix lander directly sampled water ice in shallow Martian soil on July 31, 2008. Liquid water cannot exist on the surface of Mars due to low atmospheric pressure, except at the lowest elevations for short periods. The two polar ice caps appear to be made largely of water. The volume of water ice in the south polar ice cap, if melted, would be sufficient to cover the entire planetary surface to a depth of 11 meters.
The atmosphere of Mars consists of about 95% carbon dioxide, 3% nitrogen, 1.6% argon and contains traces of oxygen and water. The atmosphere is quite dusty, containing particulates about 1.5 µm in diameter which give the Martian sky a tawny color when seen from the surface. Methane has been detected in the Martian atmosphere with a mole fraction of about 30 ppb. It occurs in extended plumes, and the profiles imply that the methane was released from discrete regions. In northern midsummer, the principal plume contained 19,000 metric tons of methane, with an estimated source strength of 0.6 kilogram per second. The implied methane destruction lifetime may be as long as about 4 Earth years and as short as about 0.6 Earth years. This rapid turnover would indicate an active source of the gas on the planet. Volcanic activity, cometary impacts, and the presence of methanogenic microbial life forms are among possible sources.
Of all the planets in the Solar System, the seasons of Mars are the most Earth-like, due to the similar tilts of the two planets' rotational axes. The lengths of the Martian seasons are about twice those of Earth's, as Mars's greater distance from the Sun leads to the Martian year being about two Earth years long. Mars also has the largest dust storms in our Solar System. These can vary from a storm over a small area, to gigantic storms that cover the entire planet. They tend to occur when Mars is closest to the Sun, and have been shown to increase the global temperature.
Mars has two moons, Phobos and Deimos, which are small and irregularly shaped. From the surface of Mars, the motions of Phobos and Deimos appear very different from that of our own moon. Phobos rises in the west, sets in the east, and rises again in just 11 hours. Deimos, being only just outside synchronous orbit—where the orbital period would match the planet's period of rotation—rises as expected in the east but very slowly. Despite the 30 hour orbit of Deimos, it takes 2.7 days to set in the west as it slowly falls behind the rotation of Mars, then just as long again to rise.
Because the orbit of Phobos is below synchronous altitude, the tidal forces from the planet Mars are gradually lowering its orbit. In about 50 million years it could either crash into Mars's surface or break up into a ring structure around the planet
Missions to Mars
Mars is currently host to three functional orbiting spacecraft: Mars Odyssey, Mars Express, and the Mars Reconnaissance Orbiter, and one on the surface, the Mars Exploration Rover Opportunity. Defunct spacecraft on the surface include MER-A Spirit, and several other inert landers and rovers, both successful and unsuccessful such as the Phoenix lander, which completed its mission in 2008. Observations by NASA's now-defunct Mars Global Surveyor show evidence that parts of the southern polar ice cap have been receding. Observations by the Mars Reconnaissance Orbiter have revealed possible flowing water during the warmest months on Mars.
Now that we've established that Mars is both pretty and interesting, what exactly will curiosity be up to when he arrives? First and foremost it will try to get an answer to one of the BIG questions; find out whether Mars could ever have supported life. Its official name is MSL, Mars Science Laboratory for a reason. It carries lots of interesting tools that allow it to run its own experiments. It will study both climate and geology as well collect data that will allow us to plan for future human missions to Mars.
Curiosity takes off - http://goo.gl/09wD2 .
Curiosity's bag of tricks - http://goo.gl/8LkoV
7 minutes of terror before touchdown
BBC Horizon: Mission to Mars
The Red Planet's is our closest neighbor. Both its proximity and status as a prime target for future human colonization ensure our continued interest and help drive more robotic missions to the Red Planet. There will come a time when we, bags of meat, will want to explore it ourselves and that time may almost be at hand. Initiatives like Mars One - http://mars-one.com/en/ - have a real chance of success. They managed to get a lot of respected individuals and companies on board and their timeline looks realistic. Perhaps they will be the ones who translate the dream into reality?