Our Solar System

SOLAR SYSTEM

Our Solar System Our solar system is made up of:

• Sun

• 8 planets

• Their moons

• Asteroids

• Comets

Sun Our Brightest Star

• Approximately one million Earths can fit inside the Sun.

• The center of the Sun, is made of hydrogen.

• There are dark blotches on the Sun's surface called Sunspots. These are cooler areas of the Sun.

• 4.5 pounds of sunlight hit Earth every second.

Our Solar System

• Consists of eight planets.

• All revolve around the Sun, which is the main source of light and heat for these eight planets.

• It is the Sun's strong pull of gravity which keeps the planets in orbit around it.

The Sun:

our nearest star

Stars have different colors

• B: blue – hottest

• A: green – warm

• C: red - cool

What can we measure?

Stellar Life • Star burns fuel in its

core (fusion: H→Helium)

• Initially fuel is H, star is on Main Sequence “Adult” (e.g. The Sun)

• When H runs out, core heats up and He, burns: “Middle Age” (Giant star)

• then He runs out, it burns heavier elements, e.g. Fe

Death of a Star • When all fuel runs out, the core collapses

• Outer regions of star explode outwards: Supernova

• SN shine more brightly than a galaxy for a few hours/days

Inner Planets

The inner four rocky planets at the center of the solar system are:

• Mercury

• Venus

• Earth

• Mars

Mercury

• Planet nearest the sun

• Second smallest planet

• Covered with craters

• Has no moons or rings

• About size of Earth’s moon

Venus

• Sister planet to Earth

• Has no moons or rings

• Hot, thick atmosphere

• Brightest object in sky besides sun and moon (looks like bright star)

• Covered with craters, volcanoes, and mountains

Earth

• Third planet from sun

• Only planet known to have life and liquid water

• Atmosphere composed of composed of Nitrogen (78%), Oxygen (21%), and other gases (1%).

Mars

• Fourth planet from sun

• Appears as bright reddish color in the night sky

• Surface features volcanoes and huge dust storms

• Has 2 moons: Phobos and Deimos

Asteroids

• Small bodies • Believed to be left over from the

beginning of the solar system billions of years ago

• 100,000 asteroids lie in belt between Mars and Jupiter

• Largest asteroids have been given names

Outer Planets

The outer planets composed of gas are :

• Jupiter

• Saturn

• Uranus

• Neptune

Jupiter

• Largest planet in solar system

• Brightest planet in sky

• 60+ moons, 5 visible from Earth

• Strong magnetic field

• Giant red spot

• Rings have 3 parts: Halo Ring, Main Ring, Gossamer Ring

Saturn • 6th planet from sun

• Beautiful set of rings

• 31 moons

• Largest moon, Titan,

• Easily visible in the night sky

• Voyager explored Saturn and its rings.

Uranus

• 7th planet from sun

• Has a faint ring system

• 27 known moons

• Covered with clouds

• Uranus sits on its side with the north and south poles sticking out the sides.

Neptune

• 8th planet from sun

• Discovered through math

• 7 known moons

• Triton largest moon

• Great Dark Spot thought to be a hole, similar to the hole in the ozone layer on Earth

Dwarf Planet

• Pluto, is a small solid icy.

• smaller than the Earth's Moon.

• NOT A PLANET!

Pluto

• Used to be 9th planet from sun (usually)

• Never visited by spacecraft

• Orbits very slowly

Comets

• Small icy bodies

• Travel past the Sun

• Give off gas and dust as they pass by

Which planet?

1. Named after the ‘God of Sea’. Placed between Pluto and Uranus.

2. Has phases like the moon. Covered in clouds – very bright object in the sky

3. Largest planet. Has a red spot

4. Known as the ‘red planet’. Has moons called Phobos and Deimos.

5. Has bright rings and many moons, including one called Titan.

Which planet?

1. Named after the ‘God of Sea’. Placed between Pluto and Uranus. [Neptune]

2. Has phases like the moon. Covered in clouds – very bright object in the sky. [Venus]

3. Largest planet. Has a red spot [Jupiter]

4. Known as the ‘red planet’. Has moons called Phobos and Deimos. [Mars]

5. Has bright rings and many moons, including one called Titan. [Saturn]