Pluto and Dwarf Planet Classification

Pluto was discovered in 1930 by Clyde Tombaugh and was initially classified as the smallest and farthest planet in the solar system. However, in 2006, it was reclassified as a dwarf planet due to new criteria set by the International Astronomical Union, which it did not meet. The discovery of Eris, another celestial body, prompted this reclassification. Despite its downgrade, Pluto remains a significant object of study, with NASA's New Horizons mission launched to explore it further.

Who discovered Pluto and in what year?

• Percival Lowell in 1915

• Clyde Tombaugh in 1930

• Galileo Galilei in 1610

• Edwin Hubble in 1923

How does Pluto's size compare to Earth's moon?

• Pluto is twice the size of Earth's moon

• Pluto is smaller than Earth's moon

• Pluto is the same size as Earth's moon

• Pluto is larger than Earth's moon

What led to the debate about the definition of a planet in 2005?

• The launch of a new space telescope

• The discovery of Eris

• The discovery of a new star

• The reclassification of Mars

Which celestial body was initially thought to be the tenth planet?

• Eris

• Ceres

• Haumea

• Makemake

Which organization set the new criteria for classifying planets?

• United Nations Office for Outer Space Affairs

• International Astronomical Union

• European Space Agency

• NASA

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

• It must not share its orbit with other bodies

• It must have a moon

• It must have a spherical shape due to gravity

• It must orbit the Sun

Why was Pluto reclassified as a dwarf planet?

• It shares its orbit with other celestial bodies

• It has no moons

• It is too far from the Sun

• It does not have a spherical shape

In what year was Pluto reclassified as a dwarf planet?

• 2015

• 2000

• 2010

• 2006

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

• To find new planets in the solar system

• To explore Mars

• To study Pluto and other dwarf planets

• To study the Sun

What is the significance of Pluto in the solar system despite its reclassification?

• It is the largest planet

• It is the closest planet to the Sun

• It remains an important aspect for study

• It has the most moons