Translate

Wednesday, March 27, 2013

Cyclones on the icy moon of Saturn - Titan


Astronomer studies the possibility of the origin of cyclones over the surface of the largest moon of Saturn - Titan, indicating some similarities to the weather with the Earth. Saturn's moon Titan, whose surface is so cold that methane falls on her in the form of rain in the summer raises its temperature so that makes it possible for cyclone zipping above the seas. Marine evaporation is able to generate enough energy to produce wind, moving at a speed of 70 kilometers per hour. However, the formation of cyclones totally depends on what is the chemical composition of the seas of Titan.


If more than half the volume of the ocean is with methane, then this chemical recipe will be enough for the emergence of the whole storm. The next step astronomers - take pictures of the storm with a spacecraft "Cassini", which is currently overflying of Saturn and its moons.
Study report current should appear in the April issue of the journal "Icarus".

Methane mystery
Cyclones occur on Earth, most of them in two ways. The first, which is not possible on Titan due to insufficient temperature difference occurs when the collision of warm and cold fronts. Warm and cold streams twist around each other, thus generating winds moving at great speed.
The second option is when the heat coming from the surface water warms the air, causing it to soar, creating, thus, energy cycle, which produces jet streams winds. Continuation of the cycle leads to rotating storms. This option is quite possible for the Titan.

These winds can occur only over those seas of Titan, which lay in the middle latitudes the moon's surface, where there is a suitable combination of temperature and humidity. Tokay says the only difficulty in this case is that scientists do not know the exact chemical composition of the seas of Titan.

"There is great uncertainty about the composition, in addition, the satellite can potentially contain many types of hydrocarbons," he said. Despite this, if most of the Seas is methane, they are able to devote enough energy for the occurrence of cyclones. Methane is the only liquid on Titan's surface, which can be condensed like water on Earth.

Detection is not a problem
Prior to that time, "Cassini" has not fixed the cyclone on Titan, as the temperatures in the northern part of the satellite are too low (the average temperature of the surface of Titan - minus 178 ° C). Summer Titan comes only in 2015, after which the "Cassini" will remain for another two years to complete all the research operations.

Signs of the cyclone should be obvious, so the problems with its detection should arise. If cyclones will show up, then we will observe a large release of energy throughout the storm area (about 100 km).
Given the resolution of the instrument "Cassini", an apparatus for detecting the cyclone need to fly up close enough to the surface of the moon, said current. In the interval 2015-2017 planned several close flybys of Titan.

It is difficult to predict what will give us the knowledge discovery cyclone, however, according to the current; it will give us an idea of ​​the temperature difference in the northern hemisphere satellite between summer and winter. "These results near the reality, a few of the climate conditions of the Earth and Titan are the same," adds the current.

No comments: