Typically, the mention of a very early planet Earth (500 million or so years after it formed) brings to mind hellish landscapes – fire and brimstone, desolation, etc. It appears now that such imagery just isn’t true. According to scientists at Vanderbilt University, the young Earth looked shockingly similar to the one we know now, complete with oceans, tectonic plates and contiguous continents.

Due to a lack of rock formations left over from what’s known as the Hadean period, scientists long concluded that Earth at the time must have been incredibly hot (if not entirely molten), inhospitable to any sort of life. That began to change with something known as zircon crystals, a mineral associated with granite that could exceed four billion years of age when dated.

“We reasoned that the only concrete evidence for what the Hadean was like came from the only known survivors: zircon crystals – and yet no one had investigated Icelandic zircon to compare their telltale compositions to those that are more than 4 billion years old, or with zircon from other modern environments,” said Calvin Miller, the William R. Kenan Jr. Professor of Earth and Environmental Sciences at Vanderbilt University.

Analysis of ancient zircons revealed that Earth was not such a hellish landscape during the Hadean period. Even if it was mostly inhospitable, there were areas and periods where the crust cooled enough for substantial amounts of surface water to pool, possible on the scale of oceans. While some argue that Earth then would have looked similar to Earth today, others say that much of the planet might have resembled modern day Iceland, where crust cools and forms from nearby basaltic magma.

The basaltic distinction is important: It’s far hotter than the magma that would have formed the continental crust during the Hadean period. The researchers reason that if zircons form out of interactions with this much hotter magma now, then the cooler, possible wetter conditions of the Hadean period mean it’s not much of a stretch to believe that the Earth was far milder at the time than classical theory suggests.

“Our conclusion is counterintuitive,” said Miller. “Hadean zircons grew from magmas rather similar to those formed in modern subduction zones, but apparently even ‘cooler’ and ‘wetter’ than those being produced today.”