PBL

Critical Thinking

What connections can you see between how the International Astronomical Union classifies planets,dwarf planets,and small solar systems objects now and in the past.

IAU

Is a member of the international council for science. Its main objective is to promote and safe guard the science of astronomy in all its aspects through international cooperation.

Research and education in Astronomy started in 1919.

Planets

defined as a celestial body that is in orbit around the sun has a sufficient mass for its self-gravity to overcome rigid body forces so that it assumes a hydrostatic equilibrium shape, and has cleaned the neighborhood around its orbit.

Dwarf Planets

is a celestial body orbiting a star that is massive enough to be rounded by its own gravity, and it is not a satellite. Currently there are five dwarf planets. Ceres,Pluto,Make Make,Eris,and Haumea.

Small Solar Systems

to encompass all objects orbiting the sun that are too small to satisfy the definition of planet or dwarf planet. Includes comets, asteroids, the objects in the Kuiper belt and the Oort cloud.

Answer

The connections that i can see between how the IAU classifies planets,dwarf planets,and small solar systems is that Planets are classifies by;

1. is it in orbit with the sun

2.has sufficient mass to assume hydrostatic equilibrium

3.has cleared the neighborhood around its orbit

Astronomers found many small planets in the 1800s and there were 23 that they had counted so they stopped calling the small planets planets and called them asteroids but today the IAU made new rules and now pluto and many other dwarf planets are not classified as planets because they do not undergo the classifications to be a planet.

The term Small Solar System body is a new IAU definition to encompass all objects orbiting the sun that are too small to satisfy the definition of planet or dwarf planet.