(NewsNation) — Scientists have long wondered why the Earth has a broken, rocky surface made up of huge plates that crash into each other. A new theory says it’s connected to the Mars-sized object that crashed into Eart about 4.5 billion years ago, which created our moon.

The authors of a new study published in Geophysical Research Letters believe that when the collision occurred, pieces of that huge object stayed behind in the form of mysterious blobs under the earth’s surface. Debris from the collision formed the moon.

Two blobs, formally known as large low-velocity provinces (LLVPs), consist of material that’s different than the surrounding earth’s mantle. One is under the African continent, another under the Pacific Ocean. Both are twice the size of the moon.

Those blobs, the theory goes, created plate tectonics – the geologic phenomenon that fuels earthquakes and volcanoes, which allow life to flourish.

“The giant impact is not only the reason for our moon if that’s the case, it also set the initial conditions of our Earth,” California Institute of Technology geoscientists and study co-author Qian Yuan told The Washington Post.

The new theory also shines a light on previous theories – or, in the case of UCLA professor T. Mark Harrison, a “non-theory.” His recent paper entitled “We Don’t Know When Plate Tectonics Began” points out geochemical inconsistencies that cast doubt on the giant impact theory itself.

“The best thing I can tell people is that my generation … couldn’t solve arguably the most interesting question left in science, which is how and under what conditions did life emerge,” he wrote.