Sun and Stars

1
Solar System

• Sun and Stars
• Planets
• Comets
• Asteroids

2
Sun Our Nearest Star

• The Sun is our nearest star.
• A star is a ball of hot gases that pours out huge
  amounts of heat, light, and other energy.
• The Sun can hold a million Earths.
• If you could fly to the Sun, it would take 17
  years.
• All life on Earth depends on the Sun.

3
Mercury Suns Nearest Planet

• Mercury is the first planet from the Sun.
• Mercury is a swift little planet.
• Mercury is dry and hot.
• Its closeness to the Sun makes it difficult to
  study.

4
Venus Hottest Planet

• The second planet from the Sun is Venus.
• Venus is hidden beneath deep, yellow sulfuric
  acid clouds.
• Venuss air is mostly carbon dioxide (the air we
  breathe out).
• The thick air around Venus acts as a blanket and
  traps the heat.
• One of the largest craters in the Solar System is
  on Venus.

5
Earth Watery Planet

• Earth is the only planet we know where life
  exists.
• Atmosphere around Earth is made of oxygen,
  nitrogen, carbon dioxide, and other gases.
• Earth revolves (circles) around the Sun once
  every 365 days (year).
• It also rotates (spins) on its axis once every 24
  hours (day).

6
Moon Our Rocky Neighbor

• Earth has one natural satellite, the Moon.
• The moon is an airless little world.
• It orbits (goes around) our planet once every
  month.
• The moon was bombarded by asteroids and so has a
  heavily-cratered surface.
• The first person to land on the Moon was Neil
  Armstrong.

7
Mars Red Planet

• MARINER 4 and two Viking flights sent back
  close-up photographs of Mars.
• Mars is a little more than half Earths size.
• It takes Mars 2 years to orbit the Sun.
• Mars soil has a lot of iron oxide (rust) that
  gives it a red color.
• Mars has 2 moons.

8
Jupiter King of the Planets

• Jupiter is the largest planet.
• It is the first of the 4 giant, gas outer
  planets.
• It has a well-known mark called the GREAT RED
  SPOT, which is 2 times the size of the U.S. It
  is an area of stormy winds.
• Jupiter has no surface. Spaceships cannot land
  on it.
• Jupiter has more than 17 moons (Ganymede is the
  largest moon in the Solar System.)

9
Saturn Planet with Ears

• Saturn was first seen by an Italian astronomer
  named Galileo.
• He said the planet had ears.
• Saturns rings are made of dust and ice.
• Jupiter is colorful, but scientists feel that
  Saturn is the most beautiful.
• Saturn has more moons than any other planet.

10
Uranus Tipped-Over Planet

• In 1781 an astronomer saw a small spot that was
  gliding backward across the sky. He knew that
  stars do not move that way. He knew it must be a
  planet Uranus.
• Like Jupiter and Saturn it is made of gas. It
  also has faint rings.
• It is tipped over on its side so that one pole
  faces the Sun giving it a day that lasts 42 Earth
  years.
• Uranus also has several moons.

11
Neptune Last Giant

• Neptune wasnt discovered until 1846.
• It was named for the Roman god of water.
• Even though it is the color of water, it is not
  made of water but of deadly gases like those
  found on Uranus.
• The Hubble telescope will help us study the
  far-out planets.

12
Pluto Last Planet?

• It is the smallest and last known planet.
• Some astronomers think that it may not be a
  planet.
• Sometimes Plutos orbit crosses Neptunes orbit.
  Then Neptune is the last planet.
• Pluto has one moon.

13
Asteroids
14
Comets