Is Pluto a Planet?

Pluto was discovered in 1930 by Clyde Tombaugh and was initially classified as the smallest and farthest planet in the solar system. However, due to its small size and shared orbit with other celestial bodies, it was reclassified as a dwarf planet in 2006. This decision followed the discovery of Eris, which led to the establishment of new criteria for defining planets by the International Astronomical Union. Despite its reclassification, Pluto remains an important object of study, with missions like NASA's New Horizons continuing to explore its characteristics and surroundings.

Who discovered Pluto and in what year?

• Clyde Tombaugh in 1930

• Mike Brown in 2005

• Galileo Galilei in 1610

• Isaac Newton in 1687

What is a key characteristic of a dwarf planet?

• It must have a strong magnetic field

• It must have a ring system

• It must orbit the sun

• It must have a moon

What was the name of the celestial body discovered by Mike Brown that led to a debate about the definition of a planet?

• Ceres

• Eris

• Haumea

• Makemake

Which of the following is NOT a criterion for a celestial body to be considered a planet?

• It must orbit the sun

• It must have a spherical shape due to its gravity

• It must clear its orbit of other objects

• It must have a moon

What was the purpose of NASA's New Horizons mission?

• To explore the moons of Jupiter

• To search for extraterrestrial life

• To study the sun's atmosphere

• To study Pluto and its surrounding area