I’m sure you’ve all enjoyed the optical illusion series that we keep posting on everynow and then. But those illusions pale in comparison to the one performed by the second largest planet in our solar system. Saturn can seemingly make its rings made up of 35 trillion-trillion tonnes of rock, dust and ice just disappear. Saturn did this yesterday i.e. the 11th of August.
It’s been doing this for quiet some time as well but we only found out about it some 400 years ago when Galileo Galilei who was observing the rings of Saturn for some years now and mistook them for its moons noted that they got smaller and asmaller and then finally disappeared.
- Saturns axis tilt. Images taken by hubble from 1996 to 2000
Now the explanation as to how Saturn performs this extraordinary feat. Each planet ‘wobbles’ on its own axis to some extent. This wobbling eventually leads to the equator of the planet getting inline with the photons of light streaming in from the sun with the result that the sun is directly above the earth. This is known as the equinox and occurs on the earth twice every year, once in march and then again in september. Saturn takes around 29 earth years to complete one orbit of the sun. On Saturn the equinox occurs twice after almost every 15 years. When the equinox occurs on Saturn the light will hit the rings of saturn edge on. The reflection from the rings is so small that they seem to vanish.
The Cassini spacecraft has been observing Saturn for the past 5 years. Cassini’s instruments are tasked with taking temperature readings on both sides of the rings as the sun sets to look at how the rings cool as they go through this seasonal variation. Cameras on the craft are trying to spot new moons and possible ring wraps inside the ring system, such things are only visible during the equinox.
