The Day in Saturn
Estimated length of Saturn's day has been revised down to 10 hours 32 minutes. Finding the rotation period of a gas planet is quite difficult. The most recent Cassini estimate last year was 15 minutes longer. This measurement directly affects estimated wind speeds. With the longer estimate, winds appeared to travel hundreds of miles per hour in the same direction around the planet. The shorter day means that winds are much slower and travel both East and West. This corresponds with observations of East-West winds on Jupiter.
Previously in Hot Gas we saw that Saturn's jet streams are driven by rotating eddies originating deep within the atmosphere. Photo below was taken August 31. Transit of Mimas, 397 kilometres in diameter, shows how huge Saturn's spiral storms are. The new estimate of Saturn's day will be published in the September 7 issue of NATURE.
UPDATE: As we have seen before, scientists are not sure how planets began forming. Since the time of Pierre Laplace, most theories involve the Solar System condensing from a disk-shaped cloud of gas. Small planetesimals would have formed from gas particles. However, particles colliding at orbital velocity will not stick together gravitationally unless they have the mass of mountains. Something else is needed to start planet formation.
Scientists believe that the Big Bang created billions of tiny Black Holes. A typical Primordial singularity would have the mass of a mountain yet be smaller than a proton. If a few of these tiny holes collided with a gas cloud, they would immediately attract matter. These singulartiies were far too tiny to suck everything up or even burn hot as a star, but the tiny amount they did eat would generate a large amount of radiation. Eventually there would be a ball of matter with a hot centre, an infant planet. The Black Hole would still be there at the planet's centre.
Saturn and gas giant planets give off far more radiation than they receive from the Sun. This heat powers the many storms seen in the atmosphere. Saturn also has a strong magnetic field creating polar auroras and a mysterious hexagon. Both internal heat and the magnetic field could be produced by a hidden Black Hole. There is far more in the Universe than meets the eye.
This week Universe Today hosts the Carnival of Space!