The inner planets are Mercury, Venus, Earth, and Mars. They are smaller and rocky compared to the outer planets. Mercury is the closest planet to the Sun and has many impact craters on its surface from meteorites. Venus is similar in size to Earth but has a dense, hot atmosphere. Earth is the only known planet that supports life. It has liquid water and an atmosphere that protects from radiation. Mars is the fourth planet from the Sun and has a reddish soil with polar ice caps that shrink and grow with the seasons. Space probes have visited and studied each of these planets.

1. What are the inner
planets?

2. The Inner plants
The four planets that are close to the Sun are
known as the inner plants.
These planets are Mercury, Venus, Earth, and
Mars.
They are all small and rocky planets
Special satellites and space probes have
provided information about the planets

3. Mercury
Mercury is the planet closest to the Sun.
It is a small planet, a little bigger than the
earth’s Moon.
Mercury is covered with thousand of dents
The dents are shaped like bowls and called
Craters.

6. Crater
A large bowl-shaped
cavity in the ground
or surface of a planet
typically caused by an
explosion or the
impact of meteorite is
know as crater

7. Crater
Crater were made when meteorites
crashed into Mercury’s surface long ago.
A meteorite is a rock from the space that
has struck the surface of a planet or a
Moon.

8. Space probes
A space probe is a vehicle that carries
cameras and other tools for studying
different objects in the space,
 In 1974 scientists sent the Mariner 10
space probe to visit Mercury.

9. Too hot and too cold
Mercury has almost no atmosphere and it is
so close to the Sun so Mercury is scorching
hot during the day.
Day times temperature is four or five times
grater than the hottest place on the Earth.
But with no atmosphere to hold in heat,
Mercury is very cold at night.

10. Venus
Venus is the second planet from the Sun.
It is about the size of the Earth but Venus turns in
opposite direction.
Mercury is very hot and dry.
Unlike Mercury Venus has an atmosphere made of
thick, swirling clouds.
The clouds of Venus are burning hot and poisonous!

11. Venus
There are strong winds
and lightening.
The clouds are good
at reflecting the Sun’s
light so this makes
Venus one of the
brightest objects in
Earth’s night sky.

12. Earth
Earth is the third planet from the sun and
the largest rocky planet in the solar
system.
Earth is the only planet that has liquid
that has liquid water on its surface.
Earth is wrapped in layers of gas that is
150 kilometer thick.

13. Earth
This layer of gas or atmosphere, makes
life possible on Earth. It also filters some
of Sun’s harmful rays.
It contains oxygen, nitrogen, carbon
dioxide, and water vapor.
Earth is the only planet that is know as to
support life .

14. The Moon
Moor are satellite of planet.
A satellite is an object that orbit another object in
the space such as the Moon revolves around the
Earth.
Earth has on large Moon. The diameter of the
Moon is about one-fourth the diameter of the
Earth.
It has many craters that formed when meteorites
crashed onto its surface.

15. Exploring the Moon
Space exploration started in 1957 when the former
soviet Union launched Sputnik, the first arterial
satellite.
The Soviet Union sent the first space probes to the
Moon in 1959.
In 1961, Yuri Gagarin, a Soviet cosmonaut, became
the first person to travel in space.
His journey on Vostok I circled Earth in less than 2
hours.

16. Exploring the Moon
In 1969 Neil Armstrong and Buzz Aldrin
were the first people to step on the
Moon’s surface.
The Moon has no atmosphere to create
wind or rain, so their footprints will
remain for years to com

17. Mars
Mars is the fourth planet from the Sun.
The rocks and soil that cover much of the
Mars contain iron oxide. This mineral is
radish-brown in color. It is the same mineral
that makes up rust.
Mars has too Moons. Deimos and Phobos.
Phobos is very close to Mars.

18. The atmosphere on Mars does not have enough
oxygen to support life.
Winds on the Mars cause dust storms that sometimes
cover the entire planet.
Mars has polar caps that grow in the winter and shrink
in the Summer.
Mars has many volcanoes on it surface.
It also has a canyon that is bigger than earth’s Grand
canyon. This canyon is more than 4000 kilometer long.
Earth’s Grand canyon in Arizona is 446 km long.

19. Space probes on Mars
Several space probes has successfully landed on Mars. The
first one Viking I, touched down on Mars in 1976.
In 1997, a 30 cm tall box-shaped robot explored part of
Mars. The robot was named sojourner has explore Mars.
Then in January 2004, the twin robot spirit and opportunity
landed on Mars. Both collected data and send it to Earth.
Scientists hope that the data will help them learn about
materials that make up mars.