S
The Inner Planets
Chapter 20 Section 3
The Inner Planets are the 4 planets closest to the Sun Mercury, Venus, Earth, and Mars
The Inner Planets are also known as terrestrial planets Terrestrial planets have rocky surfaces
The Inner Planets
Mercury is the closest planet to the Sun
Mercury is slightly larger than the Moon
Mercury
Mercury is a planet of extremes
Temperatures on Mercury can get as cold as -170oC (-274oF) and get as hot as 430o C (806o F)
Mercury has these extreme temperatures because it has a very thin atmosphere *Remember* A planet’s atmosphere is what helps
regulate the planet’s temperature (think about the Earth)
A Planet of Extremes
Venus aka the “morning star” aka the “evening star”, is the 2nd planet from the Sun Venus is not a star though, because it does not create its
own light. It shines because it reflects light from the Sun
Venus is the only planet that rotates East to West. It’s “moving backwards”!
Venus
Venus is slowww…
It takes about 7.5 months for Venus to revolve around the Sun
But it takes about 8 MONTHS for Venus to make 1 rotation.
1 Day for Venus is longer than 1 Year!!
Venus
Venus’ atmosphere is made of mostly carbon dioxide
*Remember that CO2 is a greenhouse gas
Venus is becoming hotter and hotter because it has mostly green house gas in its atmosphere Global warming is always happening on Venus
Venus’ Greenhouse
Earth is the 3rd planet from the Sun
Earth’s atmosphere is made up of 20% oxygen. This is very important for living organisms like…
humans The rest of the atmosphere is mostly made of
nitrogen and water vapor Clouds are made of water vapor
70% of the Earth is covered with water!!
Earth
Earth’s atmosphere is made up of 20% oxygen. This is very important for living organisms like…humans The rest of the atmosphere is mostly made of nitrogen
and water vapor Clouds are made of water vapor
70% of the Earth is covered with water!!
Earth
Layers of the Earth
The Earth is broken up into 3 main layers The CRUST is the outside rocky layer The MANTLE is the next layer, which is made of molten
rock The CORE is divided into a liquid OUTER CORE and a
solid INNER CORE
Earth
Mars is the 4th planet from the Sun
Mars is also known as the “Red Planet” because of its reddish surface
Mars’ atmosphere is mostly carbon dioxide
Mars – The Red Planet
Mars is the 4th planet from the Sun
Mars is also known as the “Red Planet” because of its reddish surface
Mars’ atmosphere is mostly carbon dioxide
Mars – The Red Planet
Astronomers have found remains of water on Mars The north pole of Mars contains ice!
Mars’ south pole is made of frozen carbon dioxide (aka Dry Ice)
Mars has seasons just like we do on Earth
Mars – The Red Planet