Question

Why did astronomers identify Pluto as a planet from its discovery? What scientific evidence led to its reclassification?

a) Because of its small size and irregular orbit.
b) Due to its distinctive blue color.
c) Based on the presence of a moon, Charon.
d) Pluto was initially identified as a planet, and reclassification was prompted by new evidence.

Answer 1

Pluto was initially identified as a planet from its discovery, but scientific evidence led to its reclassification as a dwarf planet due to its small size, irregular orbit, and the discovery of other similar objects in the outer solar system.

Step-by-step explanation:

Astronomers initially identified Pluto as a planet from its discovery because of its small size and irregular orbit. However, scientific evidence led to its reclassification as a dwarf planet. The discovery of Pluto's moon, Charon, in 1978 allowed astronomers to measure Pluto's mass and determine that it was far less than the mass of Earth. In addition, the discovery of other small objects in the far outer solar system similar to Pluto further supported its reclassification as a dwarf planet.