The inner planets Mercury, Venus, Earth, and Mars are similar to each other. They are the closest planets to the sun and are called terrestrial planets because they are rocky or earth-like. Mercury is the smallest planet and closest to the sun, with extreme temperature variations between its day and night sides. Venus is about the same size as Earth but has a dense carbon dioxide atmosphere that causes a runaway greenhouse effect and surface temperatures over 800 degrees Fahrenheit. Mars is about half the size of Earth, has a reddish appearance, seasonal polar ice caps, evidence of past water, and the lowest average temperature of the four inner planets.

1. Mercury
Venus
Earth
Mars
INNER PLANETS

2.  They are similar to each other.
 Closets planets to the sun.
 They are called “Terrestrial Planets”
 Terra: “Earthy or Rocky”
MERCURY, VENUS, EARTH, AND MARS
ROCKMETAL
CORE

3. Mercury is
closet to the
sun.
Same size as
our moon.
Orange in color
with lots of
craters caused
by early
impacts.
Hard to explore
because it’s so
close to the sun.

4. - Almost no atmosphere and no water
- It is so small, it’s gravity can not hold the atmosphere around it.
- It has the greatest temperature range of all planets.
The side facing the sun = HOT
The side away from sun = COLD
The core has cooled causing the surface to shrink and crack.
HOT COLD
MERCURY

5. Venus is Earth’s twin.
Same size and shape
as Earth
Yellow in color with
craters too! Carters
hard to see because
of thick atmosphere
We often see Venus
as one of the
brightest objects in
the sky.
VENUS

6. It takes 8 months to
rotate once = long
days and nights!
It takes 7.5 months to
go around the sun =
longer day than year.
It rotates backwards
“clockwise” after
being hit long ago.
Weather Report:
CLOUDY… EVERY DAY !!!
Runaway Greenhouse…
The Atmosphere:
-Thick
- Mostly Carbon Dioxide
- Atmospheric Pressure would crush us.
This thick atmosphere of
greenhouse gasses trap so much
heat it is 870°
Rotation is Funky…
VENUS

7. Mars is called the
Red Planet.
It is half the size of
Earth.
Red in color because
it has “rusted.” (Iron
Oxide)
Has 2 moons:
Phobos and Deimos
Has polar ice caps of
frozen water and
carbon dioxide
Very Cold,
temperatures reach a
frigid -81ºF
Evidence of river
channels and running
water long ago?
MARS

11. Olympus Mon
Valles Marineris