Why we'll never find another planet like Earth
Every few days, it seems, NASA discovers a new exoplanet that could "potentially" be the next Earth. But the truth is, we'll never find another planet quite like ours, argues Mark Fischetti at Scientific American. While experts are hunting for a hospitable Earth 2.0 that boasts liquid water and human-friendly temperatures, they're ignoring one factor that gives our blue planet its inimitable properties: Plants. Far from being a mere byproduct of Earth's water and soil, our trees and flora helped shape the planet's entire surface. Green life "soaked up all the carbon dioxide from the atmosphere" over 450 million years ago, lowering temperatures enough to let other organisms thrive. And the roots of forests shaped our planet's riverbeds, allowing vegetation to grow while softening the soil for agriculture. Here, Fischetti explains why Earth is truly one of a kind:
Before the era of plants, water ran over Earth's landmasses in broad sheets, with no defined courses. Only when enough vegetation grew to break down rock into minerals and mud, and then hold that mud in place, did river banks form and begin to channel the water. The channeling led to periodic flooding that deposited sediment over broad areas, building up rich soil. The soil allowed trees to take root. Their woody debris fell into the rivers, creating logjams that rapidly created new channels and caused even more flooding, setting up a feedback loop that eventually supported forests and fertile plains. ...
Even if plants do sprout [on another planet], they will evolve differently, crafting a different surface on the orb they call home.