Six-year-old Cara O'Connor of Ireland, who dreams of becoming a NASA astronaut one day, wrote a letter to the space agency urging it to reclassify Pluto as a planet, The Washington Post reported this week.Pluto was downgraded from a planet to a dwarf planet in 2006 by the governing body of astronomy, the International Astronomical Union (IAU).The decision has not gone down well with Cara and she wants NASA to "fix this problem" for her and "make Pluto a planet again.""I listened to a song and at the end of it the song said "Bring Pluto Back" -- and I would really like that to happen," Cara wrote.She talked about the Kuiper belt, a doughnut-shaped ring beyond Neptune where many dwarf planets are located, the Post reported on Saturday."I really think Pluto should be a main planet again like Mercury, Venus, Earth, Mars, Jupiter, Saturn, Uranus & Neptune, because in one video I watched called 'Let's go meet the planets,' Pluto was at the very end," she wrote.In another video, she said, Pluto "was put in the trash can and was scared by planet Earth.""This was really mean," Cara wrote, "because no one or no planet or dwarf planets should be put in the trash can."Cara's plea did not fall on deaf ears as she received a reply from James Green, Director of NASA's Planetary Science Division, who complimented her on her interest in Pluto."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. To me, it's not so much about whether Pluto is a dwarf planet or not; it's that Pluto is a fascinating place that we need to continue to study," Green wrote."I hope that you will discover a new planet, and I trust that if you continue to do well in school we will see you at NASA one of these days," he added.