ceres

[japan rocks/andromeda]

as we all know ceres is the planet in the asteroid belt but why dont they teach it to you in elementary school along with the other planets

[DanielC]

as we all know ceres is the planet in the asteroid belt but why dont they teach it to you in elementary school along with the other planets

 

Ceres is currently classified as a dwarf planet, rather than a planet. The reason for that is that it does not dominate its orbit. Ceres only has about 1/3 the mass of the asteroid belt. Contrast with all the proper planets which have (together with their moons) something like 99.999% of the mass of their orbit. In the current classification, a true planet dominates its orbit. Ceres does not dominate its orbit.

[CaptainPanic]

Curious that I never heard of this dwarf planet until now...

 

It is quite near to ourselves, and it has a diameter of 950 km across (a LOT bigger than for example the two moons of Mars, which I heard of a long time ago already).

 

Perhaps our education should somehow include a particle size distribution of the asteroid belt. Objects in the asteroid belt are really a lot larger than I thought. Thanks for the thread!

[Janus]

as we all know ceres is the planet in the asteroid belt but why dont they teach it to you in elementary school along with the other planets

 

Well if you had gone to school during the first half of the 19th century, you likely would have, along with Pallas, Juno and Vesta. All four were considered planets during that time. However, when it was discovered that they were part of a much larger group of objects, they were downgraded to "asteroid". Ceres 50 year run as a planet was just 2/3 the time Pluto held that status. Both now belong to the category of "dwarf planet".

[DanielC]

Curious that I never heard of this dwarf planet until now...

 

It was called an asteroid until the definition of "planet" was updated and the term "dwarf planet" was added. It is different from the normal asteroids because it has enough mass that gravity forces it into a round shape. That's the difference between a dwarf planet and, say, an asteroid.

 

It is quite near to ourselves, and it has a diameter of 950 km across (a LOT bigger than for example the two moons of Mars, which I heard of a long time ago already).

 

Perhaps our education should somehow include a particle size distribution of the asteroid belt. Objects in the asteroid belt are really a lot larger than I thought. Thanks for the thread!

 

Objects in the asteroid belt come in many sizes. Most are tiny. Ceres is special. Ceres has 1/3 the mass of the entire asteroid belt.