Download Solar System Notes - Miller`s Science Classroom

Solar System Notes
The Solar System
Our solar system is made up of the sun and everything that travels around it. This includes 8 planets and their
natural satellites such as Earth’s moon; dwarf planets such as Pluto and Ceres; asteroids, comets and
meteoroids.
Formed 4.6 billion years ago.
Located in the Orion Arm of the Milky Way Galaxy. There are most likely billions of other solar systems in our
galaxy.
The Sun
The sun is a star. A star does not have a solid surface, but is a ball of gas (92.1% hydrogen and 7.8% helium)
held together by its own gravity.
Since the sun is not a solid body, different parts of the sun rotate at different rates. At the equator, the sun
spins once about every 25 earth days. But on its poles the sun rotates once on its axis every 36 days.
The temperature at the sun’s core is about 15 million degrees Celsius.
☉ Symbol for the Sun
The Inner Planets
The four planets closest to the sun- Mercury, Venus, Earth and Mars- are called the terrestrial planets because
they have solid rocky surfaces.
Planet- a large, round mass that orbits a star and shines with light reflected from the star.
All planets revolve around the sun counter-clockwise in a slightly elliptical shape.
What makes a planet a planet?
It is in orbit around the sun.
Has sufficient mass to assume a nearly round shape.
It is not a satellite (moon).
It has cleared its orbit of smaller objects.
Mercury- Roman god of the sea.
Terrestrial planet.
Symbol:
Distance from sun: 57,910,000 km
Diameter: 4,878 km
Temperature: (Day) 410o C (Night ) -170o C
Surface Gravity: 3.7
Axis: 0o tilt
Day: 59 Earth days
Year: 88 Earth days
Description: smallest planet, hot, heavy, lifeless, a trace atmosphere, no moons, no rings, surface covered with
craters from meteor impact.
There is some water on Mercury in the form of ice caps. This ice hasn’t melted because it is protected from
the Sun’s heat by the shadows of craters. The largest feature on Mercury is the Caloris Basin, which is 808
miles across.
No moons.
Venus- Roman goddess of love and beauty
Terrestrial planet.
Symbol:
Distance from sun: 108,000,000 km
Day: 243 Earth days
Year: 225 Earth days
Diameter: 12,103 km
Temperature: 465o C
Surface Gravity: 8.8
Axis: 2.6o
Description: 6th largest planet, hottest planet, atmosphere of carbon and sulfuric acid, high pressure, no
moons or rings, has mountains and such. Spins clock-wise.
Venus contains a thick atmosphere. This atmosphere contains clouds made of sulfuric acid. The surface of
Venus contains many active volcanoes.
No moons.
Earth
Terrestrial planet.
Symbol:
Distance from sun: 150,000,000 km
Day: 23 hr. 56 min
Year: 365 Earth days
Diameter: 12,756 km
Temperature: 15oC
Surface Gravity: 9.8
Axis: 23.5o tilt
Description: 5th largest planet, supports life, abundant water, has one large moon and has no rings.
1 moon.
The Moon
Symbol:
Distance from Earth: 384,403 km
Day: 27 Earth days
Diameter: 3,476 kilometers
Temperature: -233 Celsius at night, to 123 Celsius during the day
Surface Gravity: 1.62
Description: The Moon is the Earth’s only natural satellite. A natural satellite is a space body that orbits a
planet. It is the fifth largest moon in the Solar System.
Anything that orbits a planet is called a satellite.
Mars- Roman god of war.
Terrestrial planet.
Symbol:
Distance from the sun: 228,000,000 km
Day: 24 hr. 37 min
Year: 1.88 Earth years
Diameter: 6,794 km
Temperature: -50o C
Surface Gravity: 3.7
Axis: 25o tilt
Description: Called the red planet because of the reddish surface, 7th largest planet, has an atmosphere with
clouds and water, there is water in the polar ice and possibly under the surface, surface is made up of craters,
has 2 rings and no moons.
Mars has permanent ice caps at both poles made up of solid carbon dioxide (dry ice). There are very strong
winds and vast dust storms.
Olympus Mons is the largest volcano in our solar system. It rises up 78,000 feet (3 times the size of Mt.
Everest). Another feature on Mars is Valles Marineris. This is a network of canyons that are 4000 km long and
7 km tall. Mars has two moons which are called Phobos and Deimos (asteroids, not round).
Asteroid Belt
Theory:
- The gravity of Jupiter fights with the gravity of the sun to prevent planet formation.
- Two planetary objects collided forming the asteroid belt.
Asteroid - a small rocky body (that is not a planet) orbiting the sun.
All asteroids in the belt combined would be smaller than the moon.
Main Belt- Asteroids in the belt.
Near Earth Belts- Asteroids near the Earth.
Trojans- Asteroids in the orbit of Jupiter.
The dwarf planet Ceres is in the asteroid belt.
The Outer Planets
The outer planets beyond the orbit of Mars are called gas giants. These planets are called Jupiter, Saturn,
Uranus and Neptune. Two of these planets (Uranus and Neptune) are also called ice giants.
Meteoroites
Meteoroids- chunks of rock and debris flying through space.
Meteoroids become meteors -- or shooting stars -- when they interact with a planet's atmosphere and cause a
streak of light in the sky. Debris that makes it to the surface of a planet from meteoroids are called meteorites.
Meteorites may vary in size from tiny grains to large boulders.
Jupiter- The king of the Roman gods.
Gas Giant.
Symbol:
Distance from the sun: 788,300,000 km
Day: 9 hr. 55 min.
Year: 11.8 Earth years
Diameter: 142,822 km
Temperature: -150o C
Surface Gravity: 23.2
Axis: 3o tilt
Description: Largest planet, atmosphere is mostly helium with hydrogen. The great red spot is a huge storm.
Has a solid core covered with liquid hydrogen, 63 known moons and 3 rings.
Jupiter is so big that you could cram 1000 Earths inside of it. Jupiter has alternating bands of different colored
gases. The light colored bands are called zones and the dark colored bands are called belts. It is thought that
Jupiter’s “great red spot” is a storm of swirling gas that has lasted for hundreds of years. The Great Red Spot is
the size of 2 Earth’s put together. Jupiter has one faint ring made of very small grains of rock. The 4 largest
moons of Jupiter are called Io, Europa, Ganymede (largest moon in our solar system) and Callisto. Jupiter has
at least 63 moons.
Saturn- Roman goddess of agriculture.
Gas Giant.
Symbol:
Distance from sun: 1,433,000,000 km
Day: 10 hrs. 40 min.
Year: 29.5 Earth years
Diameter: 120,536 km
Temperature: -180o C
Surface Gravity: 9.0
Axis: 27o tilt
Description: Second largest planet, atmosphere of Hydrogen and Helium, has a small core, covered with liquid
hydrogen, has lowest density, 7 rings, 60 known moons and Titan is its largest moon.
Saturn’s rings are made up of mostly water and ice, but they may also include rocky particles with icy coatings.
These rings are very thin, but very wide.
Uranus- Ancient Greek king of the gods.
Gas Giant.
Symbol:
Distance from the sun: 2,870,000,000 km
Day: 17 hrs. 14 min.
Year: 84 Earth years
Diameter: 51,120 km
Temperature: -210o C
Surface Gravity: 8.7
Axis: 97.9o tilt
Description: The 3rd largest planet, first planet discovered by a telescope, atmosphere is mostly Hydrogen and
Helium, blue-green color indicates methane, has 27 known moons and 13 rings.
Uranus’ blue color is the result of a gas called methane found in the planet’s upper atmosphere. Like the
other gas giants, Uranus has rings made up of fine dust particles. It’s brightest ring is called Epsilon. This is a
very windy planet and winds reach up to 200 mph.
Neptune- Roman god of the sea.
Gas Giant.
Symbol:
Distance from sun: 4,497,000,000 km
Day: 16-18 hrs
Year: 165 Years
Diameter: 59,528 km
Temperature: -220o C
Surface Gravity: 11.1
Axis: 28.8o tilt
Description: 4th largest planet, atmosphere is mostly Hydrogen, Helium and Methane, may have a layer of
liquid water and methane/ammonia that changes to solid, storms in atmosphere, 13 known moons and 9
known rings.
Like Uranus, Neptune’s blue color is the result of methane gas. Neptune’s winds are the fastest in the solar
system reaching 2000 mph. There are two big storms on Neptune. One of the storms is called the Great Dark
Spot and it is about the size of Earth. The second spot is called The Scooter. It is a white spot that looks like a
hurricane and whips around Neptune’s surface. Neptune has 9 rings, but like Jupiter they are very thin and
dark. The largest moon around Neptune is called Triton.
Pluto- Roman god of the underworld.
Terrestrial
Symbol:
Distance from sun: 7.5 billion km
Dwarf planets orbit our sun. Most are located in the Kuiper Belt.
Dwarf planets are solid rocky and/or icy bodies.
Pluto was considered a planet until 2006. The discovery of similar-sized worlds deeper in the distant Kuiper
belt sparked a debate that resulted in a new official definition of a planet that did not include Pluto.
Pluto has five moons, the biggest moon is called Charon. This moon is half the size of Pluto. Sometimes Pluto’s
orbit crosses in front of Neptune’s. So sometimes Pluto is farthest out and sometimes Neptune is farther out.
Pluto and Neptune will never collide because Pluto’s orbit is tilted.
Comets
Short-period comets (comets that orbit the sun in less than 200 years) reside in the icy region known as the
Kuiper Belt beyond the orbit of Neptune
Long-period comets (comets with long, unpredictable orbits) originate in the far-off reaches of the Oort Cloud.
Comets are cosmic snowballs of frozen gases, rock and dust.
A comet warms up as it nears the sun and develops an atmosphere, or coma. The coma may be hundreds of
thousands of kilometers in diameter.
The tail of a comet always points away from the sun due to solar wind.
Kuiper Belt & Oort Cloud
The Kuiper Belt and the Oort Cloud are regions of space. The known icy worlds and comets in both regions are
much smaller than Earth's moon.
The Kuiper Belt is a doughnut-shaped ring, extending just beyond the orbit of Neptune. The Oort Cloud is a
spherical shell.
There may be are hundreds of thousands of icy bodies larger than 100 km (62 miles) and an estimated trillion
or more comets within the Kuiper Belt. The Oort Cloud may contain more than a trillion icy bodies.
Technology in Astronomy
Technology has always been a big help in making discoveries in science.
Without technology, we wouldn’t have discovered anything in our solar system.
We are going to see how telescopes, rockets and computers have helped our exploration of space.
Telescopes
A telescope is an instrument designed to make distant objects appear closer.
There are 3 features on a telescope that help us see a clearer image:
1- It has the ability to gather light so we can see faint objects.
2- It has resolution which helps us see tiny details.
3- It has magnification to make objects look bigger.
There are 2 types of telescopes.
1- Refractor telescope.
2- Reflector telescope.
1- A refractor telescope uses a glass lens that bends light that comes into the telescope.
2- A reflector telescope uses mirrors for light to bounce off of and the image comes into focus at our
eyes.
Rockets
We have many instruments that help explore space such as satellites, spacecrafts and rockets.
Rockets move by releasing energy in one direction which results in movement in the opposite direction.
 release energy (action)
 Rocket moves forward (reaction)
Rockets follow Newtons 3rd Law: for every action there is an equal and opposite reaction
Computers
The invention of the computer has advanced the space exploration projects! Computers are useful in that they
help us.
1- collect and interpret data from observations
2- Predicting motion of objects
3- Help us operate spacecrafts
Because of this we know what other planets look like and how they move in our solar system.
How does the moon stay in orbit around Earth? How does Earth stay in orbit around the sun?
Objects are kept in orbit by:
1- Gravitational pull
2- Forward speed
All objects have mass. Some have more mass than others.
There is a rule that states:
The greater the mass of an object, the greater the gravitational pull needs to be.
Example: swinging a 2 year old vs. swinging a 40 year old.
Weight- how much gravity is pulling down on a certain mass.
You can figure out how much as object would weigh by knowing the gravity and mass of an object.
So… weight on each planet?
(mass + 75 kg or 150 lbs.)
Mercury
Gravity = 3.7
Mass = 75
Weight = 56.7
Venus
Gravity = 8.8
Mass = 75
Weight = 136
Moon g= 1.62
Earth g= 9.8
Mars g= 3.7
Jupiter g= 23.2
Saturn g= 9.0
Uranus g= 8.7
Neptune g= 11.1
Pluto g= .658
The sun g= 274
w= 24.9
w= 150
w= 56.7
w= 354.6
w= 159.6
w= 133.3
w= 168.7
w= 10
w= 168.7