Saturn is the sixth planet in the solar system; it is the second largest and one of the gas giants along with Jupiter, Uranus and Neptune.
As a planet far away and extremely different from ours (Saturn is mostly made of gases, takes about thirty years to go around the sun, is 9 times larger than Earth and is surrounded by a striking ring system), Saturn has always had puzzles for scientists.
One of its mysteries has been the hexagon of Saturn, a figure that can be seen at one of its poles, of which different artificial satellites have taken photographs. It is believed that it may be the result of turbulent flows that never stop, although this is not a definitive answer.
Although it draws the attention of experts for years; much greater the mystery became recently, when Saturn’s hexagon mysteriously changed color.
What happened to the hexagon of Saturn? The hexagonal-shaped region at Saturn’s north pole was photographed in its natural color by NASA’s Cassini spacecraft in 2012 and 2016.
To the surprise of scientists, in 2012 Saturn’s hexagon looked blue, but in 2016 it has changed to a mustard yellow or gold. Four years is a relatively short period for a planet’s surface to change color drastically, so astronomers are trying to figure out what happened.
What could have caused Saturn’s color change?
Scientists have not yet reached a definitive conclusion about what happened to the huge planet. One of the hypotheses holds that the change in color at the pole is due to an effect produced by the seasons on the planet.
Because Saturn’s axis is tilted as it revolves around the Sun, it has seasons like those on planet Earth. But the big difference is that Saturn’s seasons last more than seven years.
As the technology to take color images of the planets of the solar system is relatively recent, it may be that the color changes of previous seasons have gone unnoticed. In addition, 30 years ago it was not summer on Saturn, as it will be in 2017.
In particular, the change from a bluish color to a more golden hue may be due to the increased production of photochemical fogs in the atmosphere as the north pole approaches the summer solstice in May 2017.
The researchers believe that the hexagon could be acting as a barrier that prevents mist particles produced from outside from entering.
During the seven long years of winter, the polar atmosphere was freed from aerosols produced by photochemical reactions, but since the planet experienced the equinox in August 2009, the polar atmosphere has been constantly illuminated by the sun. That, in combination with other effects, such as changes in atmospheric circulation, could be the explanation for the change in color.
The mysterious hexagonal zone has a diameter twice that of planet Earth, and reaches 97 kilometers into the Saturnian atmosphere, according to thermal images.