The Red Planet emitted repeatedly gigantic steam or smoke. On the cause and the composition of the vapor is puzzled. The southern hemisphere of Mars (here without the mysterious clouds). The Mars emits powerful steam or smoke plumes that extend up to an altitude of about 250 kilometers. Thus, the plume rise above the ordinary Martian clouds. An international group of astronomers has this phenomenon been scrutinized and suggests possible explanations. Neither ice crystals, dust, auroras could the mysterious clouds based on current knowledge of the Martian atmosphere clearly explain the group to Agustin Sanchez-Lavega of the University of the Basque Country in Bilbao in the journal “Nature” writes.

The known Martian clouds of carbon dioxide or water ice extend to a height of 100 kilometers, the known dust clouds may rise to 60 km altitude. The aurorae on Mars were previously observed up to an altitude of 130 kilometers, the scientists write.

First observed clouds of steam
12 March 2012 amateur astronomers reported that they had seen with their telescopes the smoke or steam flags on the southern hemisphere of Mars. Over the next ten days, the ominous clouds were observed repeatedly in the same location on Mars morning, but never on Mars evening. This close Sánchez-Lavega and his colleagues that the clouds rapidly change and have a cyclical behavior.

From 6 to 16 April 2012, a similar phenomenon was observed at approximately the same location. Sánchez-Lavega and his colleagues measured in the formation an extension of up to 1,000 kilometers – both north-south and east-west direction. The researchers have also spotted earlier images of the Red Planet. They came across a photo of the Hubble Space Telescope of 17 May 1997, which shows a similar phenomenon. These recordings were included in addition to the images of 2012 in the analysis.

Water ice or frozen carbon dioxide?
Simulations of changes in the atmosphere of Mars known have Sánchez-Lavega and his colleagues, the observations so far can not explain clearly. The best fit water ice particles with a size of about 100 nanometers (millionths of a millimeter) – but would the temperature in the upper atmosphere then about 50 degrees Celsius to be lower than it is based on current knowledge. In the case of carbon dioxide ice, the discrepancy would amount even to 100 degrees. The suspected auroras would be 1000 times as bright as their counterparts on Earth. Therefore, according to the astronomers further observations are needed to isolate the cause can.

Paul Hartogh from the Max Planck Institute for Solar System Research in Göttingen belongs to a workgroup, which models the lower Martian atmosphere. He holds the statements of researchers led by Sánchez-Lavega is valid, and also favors tiny ice crystals as an explanation.

Finally ice crystals are also responsible for the noctilucent clouds in Earth’s atmosphere. Density variations in the Martian atmosphere could lead to these high clouds. To bring the ice particles in such a height, it needed extreme vertical wind speeds, says Hartogh.

Cloud formations there are many planets and moons of our solar system. The most famous is the “Great Red Spot” of Jupiter: There is a giant hurricane in an atmosphere of hydrogen, helium, ammonia, methane and other substances.