DRAMATIC images of the last unexplored world in the solar system have flooded the nation’s consciousness this week.

But in all the excitement of NASA’s New Horizons spacecraft completing a flyby of Pluto, it’s easy to forget where the dwarf planet first got its name.

At a breakfast table in North Oxford back in 1930, the 11-year-old Venetia Phair, then Venetia Burney, was shown an article in The Times about the unnamed frozen planet by her grandfather, Falconer Madan, the retired librarian at the Bodleian.

Young Venetia had enjoyed studying the Greek and Roman myths at school and suggested the planet be named Pluto after the Roman god of the underworld.

Ginita Jimenez, who years later directed a documentary on Mrs Phair’s life, Naming Pluto, said: “Pluto was the most obvious choice, but it took an 11-year-old to think of it.”

Her grandfather put it to his friend Herbert Hall Turner, a professor of astronomy at Oxford University, who presented it at a meeting of the Royal Astronomical Society in London. It stuck, and Mrs Phair and her school were given £5 each as a reward.

Mrs Phair went on to study maths at Cambridge University and became an economics teacher, avoiding the limelight up until her death in 2009.

Ms Jimenez, who met Mrs Phair to film the documentary a year earlier, said: “She was very private and modest about her contribution to astronomical history.

“In 2008, she had never seen or been shown the planet on a telescope. I made it my mission to make sure we did, and it was wonderful.

“She was incredibly generous with her time. I met her in the ‘closing chapters’ and she was lovely and warm.”

Colin Harris, superintendent of reading rooms at the Bodleian Library, confirmed Venetia’s story was true.

Also the vice-president of the Oxfordshire Family History Society, he added: “Her grandfather was the librarian, but her great uncle, Henry George Madan, named the two moons of Mars – Phobos and Deimos. The family has a good planet-naming tradition.”

For the first time in history, Pluto’s surface is being mapped out by photos from the New Horizons probe, which travelled 3.6 billion miles to reach its destination.

Images show a smooth surface with lumpy terrain and huge mountains made of ice.

Hayley Flood, head scientist at Space Studio Banbury, said: “It’s one of the most significant things we have done in astronomy since the Voyager fly-bys and Pluto has a place in many people’s hearts. The students are very excited.”