Following on from yesterday’s post about orreries, I’ve decided to do a quick release with two changes.

First, the promised option to disable the click noise. I’ve also turned the volume down on it a bit, when it is enabled.

Secondly, rounding out the planets, as defined by science, Solar Explorer now has information about the core of Neptune, the other ice giant in our Solar System.

“Ice” is a counter-intuitive term used by planetologists to define the melting point of certain volatiles, whether they are in a solid, liquid or gaseous state.

Elements such as hydrogen and helium have a melting point below 100 degrees kelvin, so they are called gasses,while other elements such as methane and ammonia melt above 100 degrees kelvin, so they are called ices.

Because Uranus and Neptune have a lot of ammonia and methane, they are classed as ice giants even though the interior of these planets, where the “ices” are located, are under incredibly high pressures and temperatures, and these “ices” are in a liquid state.

Saturn and Jupiter on the other hand are almost entirely composed of hydrogen and helium, so they are gas giants.

Makes perfect sense.

To a planetologist.