Planetary core facts for kids
Every planet has a center, or a core. The planetary core is the deepest part of a planet. It's like the very middle of an apple! This core can be made of different materials. It can also be a solid or a liquid layer.
Contents
Cores of Rocky Planets
Rocky planets are also called terrestrial planets. These are planets with a hard, rocky surface. Think of Earth, Mars, and Venus. Their cores are mostly made of iron.
Earth's Core
Our own Earth's core is special. It has both liquid and solid parts. The outer part is liquid iron. The inner part is solid iron. This movement of liquid iron helps create Earth's magnetic field. This field protects us from harmful space radiation.
Mars and Venus Cores
The cores of Mars and Venus are different. Scientists believe they are completely solid. Because their cores are solid, they do not create a strong magnetic field. This is why these planets are less protected from space weather.
Cores of Gas Giants
Gas giants are huge planets. They are mostly made of gases like hydrogen and helium. Think of Jupiter and Saturn. Even though they are mostly gas, they still have a core!
What Gas Giant Cores are Made Of
Their cores are also thought to be made of iron. But these cores are very small compared to the planet's huge size. Imagine a tiny pea inside a giant balloon!
Size of Gas Giant Cores
Even though they are small in proportion, gas giant cores can still be enormous. For example, Jupiter's core is estimated to be 12 times heavier than Earth's entire mass! This shows how truly massive gas giants are.
How Core Sizes Differ
The size of a core can be very different for each planet or moon. It's not always the same percentage of the object's total size.
Examples of Core Sizes
- The moon's core is quite small. It makes up only about 20% of its total radius.
- But Mercury has a huge core! Its core takes up about 75% of its entire radius. This makes Mercury's core much larger in proportion to its size than the Moon's.
See also
In Spanish: Núcleo (geología) para niños
