Question

Volcanoes played a big part in creating Earth's early atmosphere, but what else do scientists believe helped develop it?

plate tectonics

comets and asteroids

solar energy

gravity from Jupiter

Answer 1

Comets and asteroids.

Scientists think much of Earth's early volatile inventory (water, carbon, nitrogen and other gases) was delivered by impacts from comets and volatile-rich asteroids during the planet’s accretion and the later heavy bombardment, supplementing volcanic outgassing.