Safely tucked inside a Mars Science Laboratory spacecraft, Curiosity left for the Red Planet on November 26, 2011. TIME notes that it was the dramatic August 5 landing - dubbed the "seven minutes of terror" - that drew the world's attention, perhaps earning it the prestigious nod.
But the Curiosity rover's accomplishments stretch far beyond its grand entrance.
Just three months into her two-year mission, Curiosity has already returned more than 23,000 raw images, driven 517 metres and delivered history-making data about the mysterious Red Planet. And she delivers this information to the public via a quirky social media personality managed by a three-woman team at NASA.
Curiosity celebrated her birthday at a site called Point Lake, where the rover team intends to find a target for first use of the rover's rock-sampling drill.
While Curiosity may not be an actual person, the robot has made significant scientific advancements that will forever shape mankind's understanding of Mars - a qualification that makes the car-sized rover worthy of the nomination.
Curiosity wasn't the only non-human to make TIME magazine's annual list. The Higgs Boson Particle is also a contender for "Person of the Year".
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