Smaller planets might be born when gas and dust is squeezed between larger worlds like the filling in a cosmic sandwich.
The newly suggested process — dubbed "sandwiched planet formation" — would occur in the massive disks of planet-birthing gas and dust that swirl around stars in their infancy called "protoplanetary disks." Around 4.5 billion years ago, the solar system itself would have existed as one such disk around the infant sun from which the planets arose.
