Is there a reason why we have four “rock” planets lined up followed by four “gas” planets in a row, or is it merely coincidence?

Question

Is there a reason why we have four “rock” planets lined up followed by four “gas” planets in a row, or is it merely coincidence?

In: Planetary Science

Answer 1

There is sun wind that blow away the gas of the planet that close to the sun, so we have rock planet. The further from the sun, the weaker the sun wind, so we have gas planet