She also mentioned the Kuiper Belt in her letter, correctly describing it as an area beyond Neptune that houses several dwarf planets.
The young astronomy enthusiast dreams of discovering a planet one day and naming it Planet Unicorn.
Six-year-old echoes our sentiments: Make Pluto a planet!
Fix this problem for me: Six-year-old to NASA
Asking NASA to "fix this problem," Cara said, "Pluto was put in the trash can and was scared by planet Earth. This was really mean because no planet or dwarf planets should be put in the trash can."
"I listened to a song and at the end, it said 'Bring Pluto Back' - and I would really like that to happen," she added.
NASA responds to Cara's letter
Cara's letter caught media's attention when it elicited a response from James Green, Director of NASA's Planetary Science Division.
"I agree with you that Pluto is really cool - in fact, who would have believed that Pluto has a heart? It's a fascinating world that appears to be constantly changing," he wrote back, impressed with Cara's knowledge of the Kuiper Belt.
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Cara has always been curious about outer space
Cara's teacher Sarah O'Donovan, with whose help the letter was written and sent, said that the six-year-old always has questions like why do black holes exist and whether the moon landing really happened.
"She has the most interesting mind. She asked questions that I couldn't answer. She's always interested in things that are far, far above her level," O'Donovan added.
Scientists don't always have to be unreachable
Post the media coverage, Carly Howett, a Colorado-based scientist involved in NASA's mission to explore Pluto, also wrote a letter to Cara.
"I hope that this story shows that scientists don't have to be unreachable, that we're people. If you have a question, you reach out to whoever it is, whether it's Neil deGrasse Tyson or someone else. That's how curiosity starts," she said.
Pluto was downgraded to a dwarf planet in 2006
Pluto was downgraded to a dwarf planet in 2006 by the International Astronomical Union because it only met two out of the three criteria needed to be a full-sized planet.
It orbits the sun and assumes a nearly round shape, but it also records a presence of other celestial bodies of similar size in its vicinity, preventing it from being accepted as a planet.