Planet

The International Astronomical Union has set criteria for classifying planets, requiring them to have sufficient gravitational mass to form a round shape and clear their orbit of other objects. As a result, Pluto is no longer considered a planet, leaving our solar system with eight recognized planets.

What organization is responsible for defining the criteria for a planet?

• SpaceX

• European Space Agency

• International Astronomical Union

• NASA

Which of the following is a requirement for a celestial body to be considered a planet?

• It must be the largest object in its orbit

• It must be made of gas

• It must have enough gravitational mass to form a round shape

• It must have a moon

What does it mean for a planet to 'sweep the region of its orbit free of other objects'?

• It must have a clear path around the sun

• It must have no moons

• It must orbit faster than other objects

• It must be the only object in its orbit

Why is Pluto no longer classified as a planet?

• It is too far from the sun

• It does not meet the criteria of clearing its orbit

• It is not round

• It does not have enough moons

How many planets are currently recognized in our solar system?

• 7

• 10

• 8

• 9