Does thermal equilibrium exist in solar system?

In thermal equilibrium the rms velocity of a gas molecule is

What are the conditions of spontaneity and equilibrium for a process in an isolated system?

In which of the following equilibrium systems is the rate of the backward reaction favoured by increase of pressure ?

Consider the given diagram. An ideal gas is contained in a chamber (left) of volume V and is at an absolute temperature T. It is allowed to rush freely into the right chamber of volume V which is initially vacuum. The whole system is thermally isolated. What will be the final temperature of the system after the equilibrium has been attained ?