Thumb Appreciation Day

Pluto Day is a holiday celebrated by astronomers, physicists, and space enthusiasts all over the world. It is held annually on February 18. On this day, people remember the most mysterious world in the solar system. Perhaps someday, intelligent life will be discovered on Pluto, and Earth’s inhabitants will be able to establish contact with its residents.

History

Pluto was discovered by American astronomer Clyde Tombaugh, who devoted his life to studying space. He lived to be 90 years old and requested that his ashes be sent near Pluto’s surface—a wish that was honored with NASA’s New Horizons mission. Pluto Day is recognized by astronomers around the world, though it is not an official public holiday in any country. The only spacecraft ever sent from Earth to Pluto is New Horizons, which launched in 2006 and performed a historic flyby in 2015.

Interesting Facts

• The official announcement of Pluto’s discovery was made on February 18, 1930. In 1905, American astronomer Percival Lowell predicted the existence of a ninth planet through mathematical calculations, initially calling it “Planet X.”
• An American schoolgirl suggested naming the planet “Pluto” after the Roman god of the underworld, who dwelled in darkness.
• Researching Pluto is extremely difficult due to its great distance from Earth, making it one of the most mysterious worlds in our solar system.
• Pluto has some of the harshest conditions in the solar system, with temperatures dropping to minus 230 degrees Celsius. One year on Pluto lasts about 248 Earth years.
• Pluto has vast ice formations and glaciers—three times more than on Earth. It is also six times smaller than the Moon, which is why modern astronomers classify Pluto as a dwarf planet rather than a true planet.

How to Take Part

To celebrate Pluto Day, read books or articles about space, watch documentaries about planetary exploration, or enjoy music inspired by the cosmos. Spend an evening stargazing with a telescope, or attend a public astronomy event. Around the world, astronomers host scientific conferences and seminars to discuss the mysteries of Pluto and other celestial bodies.

When is Pluto Day in 2026?

Pluto Day is observed on February 18 each year.

Observations