AUSTRIA – The International Astronomical Union (IAU) is having a special conference, to determine if Saturn, is effectively a planet.
Saturn is the sixth planet from the Sun and the second largest in the Solar System, after Jupiter. It is a gas giant with an average radius about nine times that of Earth, and is known for the prominent “ring system” surrounding it.
Astronomers claim, however, that it does not meet the three criteria to be considered a planet. These criteria were determined during an international meeting of the IAU in 2006, and led to the “demotion” of Pluto to the status of dwarf planet.
The criteria to be considered a planet is the following:
- The object must orbit our sun.
- It must have enough gravitational pull to create a spherical shape.
- The object must be large enough and have enough gravity to pull planetary matter to itself and, essentially, clear the region around the object of debris.
Pluto meets the first two criteria, but not the third, it is now considered to be a dwarf planet, and many astronomers demand for Saturn’s status to be reconsidered for the same reason.
Astronomer Mike Brown, of the California Institute of Technology in Pasadena said :
“Saturn’s case resembles Pluto’s in many aspects, In fact, I think neither of them should ever have been called a planet, in the first place. Pluto is a small, spherical planetoid which is not large enough to ‘clear the neighborhood’ of debris within its own orbital zone. Despite its larger size, Saturn doesn’t seem able to really ‘clear’ anything either. Its atmosphere is full of debris and it has many moons and moonlets. If we apply the same criteria, Saturn is definitely not a planet either.”
Saturn has a prominent ring system that consists of nine continuous main rings and three discontinuous arcs and that is composed mostly of ice particles with a smaller amount of rocky debris and dust. Sixty-two moons are known to orbit Saturn, of which fifty-three are officially named. This does not include the hundreds of moonlets comprising the rings.
Members of the International Astronomical Union will now have to determine if Saturn’s status should be changed because of all these debris and satellites, or if they should on the contrary, review their formal definition of a planet.
The argument about Saturn’s status has already steered a lot of emotion within the scientific community and on the social media, so heated debates are to be expected during in Vienna, over the weekend.