Hi folks,
I was reading a book on the solar system and it mentioned that the two gas giants Saturn and Jupiter have no rocky core but are made up entirely of gas.
How do scientists know that this is true? Have there been probes that have gone into them?
Thanks in advance for your answers
IANAAstronomer, but I don’t think that it is commonly believed among astronomers that these planets have no cores-
howver the question remains as to what the cores are made of in detail,
as it is difficult to eyeball the reality.
Here are views of the insides of the two planets;
(quote from this site) The outer layer is primarily composed of molecular hydrogen. At greater depths the hydrogen starts resembling a liquid. At 10,000 kilometers below Jupiter’s cloud top liquid hydrogen reaches a pressure of 1,000,000 bar with a temperature of 6,000° K. At this state hydrogen changes into a phase of liquid metallic hydrogen. In this state, the hydrogen atoms break down yeilding ionized protons and electrons similar to the Sun’s interior. Below this is a layer dominated by ice where “ice” denotes a soupy liquid mixture of water, methane, and ammonia under high temperatures and pressures. Finally at the center is a rocky or rocky-ice core of up to 10 Earth masses.(/quote)
SF worldbuilding at
http://www.orionsarm.com/main.html
Thank you— that makes sense.
It’s a fairly straighforward calculation to figure out the atmospheric pressure at any depth under the cloud tops. If you know the pressure and temperature, which can also be estimated with some accuracy, you know whether any given element will be present as a solid, liquid, or gas.
In the books 2010 and 2061 by Arthur C. Clarke, he raises the possiblity that the carbon present in Jupiter’s atmosphere has, by the immense pressure, been compressed into a single diamond. Don’t know how plausible this idea is, though, or whether it’s original to him.