Space Science Part 1: Our Solar System

Space Science Part 1
Our Galaxy

​Lesson Objectives

• Describe how the Nebular Theory accounts for the main attributes of our solar system

• Identify the different parts of our solar system

​The Solar System and Its Formation

• Our Solar System is a collection of objects gravitationally bound to the Sun

  • Planets: Major bodies large enough to have their own gravity but small enough not to have nuclear fusion occur in their cores

    • Our eight planets follow an elliptic orbit

    • Dwarf planets exist on the outer edges (ex: Pluto)

  • Moons

  • Asteroirds

  • Comets

• The Sun is the center of the Solar System and accounts for 99% of its mass

  • The farther from the sun, the slower the object orbits

The Inner Planets

• The four planets of the solar system that are closest to the sun

  • Mercury

  • Venus

  • Earth

  • Mars

• All are Solid and Rocky

• Are also called terrestrial planets due to their solid nature that resembles Earth

​The Outer Planets

• The last four planets, farther away from the sun

  • Jupiter

  • Saturn

  • Uranus

  • Neptune

• Are large and up of Gases

• All have ring systems, but they are not always large enough to see​

• Are also called Jovian Planets because of their resemblence to Jupiter

Explaining the Solar System

• Any Theory used to explain the solar system needs to explain two things

  • The motions of the large bodies of the solar system

  • Why can the planets be divided into two groups

• The modern Scientific theory that does this is The Nebular Theory

Nebulae

• Nebula: cloud of gas and dust​

  • Nebulae are breeding grounds for stars

    • Concentrations of gas and dust floating in space

• We classify Nebula based on how they interact with light

  • Reflection Nebulae reflect light

    • Has a Bluish Hue

  • Emission Nebulae emit light

    • Have a red hue

  • Dark Nebula neither emit or reflect light

    • are opaque to light and have a dark appearance

Nebular Theory

• ​Nebular Theory: Sun and planets formed out of a nebula

• The Solar System began to condense together ~5 Billion Years Ago

• Gravity pulls the Nebula inwards, causing it to shrink and take on a spherical shape

  • As it shrank, it began to rotate faster, causing it to flatten

Nebular Theory-Formation of the Sun

• As the Nebula condensed, some regions became more dense in some regions

  • This gave these regions a stronger gravitational pull

• As pressure increased in the center, the temperature increased enough for nuclear fusion to occur, and the sun formed

  • The heat radiated by the sun caused the inner planets to develop heavier atoms than those on the outer planets, making them more solid

Multiple Choice

The Sun Contains approximately what percentage of the solar system's Mass?

• about 35 %

• 85%

• The percentage changes over time

• 99%

Multiple Choice

Planets have elliptical orbits with the _______ at (near) one focus point.

• Moon

• Planet

• Sun

• Asteroid Belt

Multiple Choice

True or False: The farther away a planet is from the Sun, slower its orbital speed.

• True

• False

Multiple Choice

The four inner planets of our solar system are also called...

• gas giant planets.

• interplanetary asteroids.

• terrestrial planets.

• jovian planets

The Sun

• Rotates around an axis, but not all together, because it is a fluid

  • Some parts finish their rotation before others

• The sun is the solar system's power supply​

• Has multiple layers

The Outer Sun

• Photosphere: The surface of the sun that emits light

• Chromosphere: Layer above the photosphere,

  • a transparent shell of plasma

• Corona: the outermost region of the Sun's atmosphere

  • Source of Solar wind- a stream of high-energy charged particles

    • cause the aurora borealis

    • Can cause disruptions in satellites

  • Solar prominences: Dense clouds of plasma in the corona

    • can cause electrical problems on Earth

The Inner Sun

• Solar Core: Center of the sun, where reactions take place

  • Hydrogen atoms smash together to form helium through thermonuclear fusion

    • The elements exist in the plasma state of matter

    • As fusion occurs, mass is lost and converted to energy

  • about 10% of the sun's total volume

  • is very hot​

The Inner Planets-Mercury

• Mercury

  • Planet nearest the sun

  • Larger than the moon

  • Completes one revolution around the sun in 88 days​

    • Only rotates on its axis once per revolution, so day time lasts very long

  • Is only seen close to sunrise and sunset

The Inner Planets-Venus

• The second planet from the sun

• Usually brighter than Mercury, bright enough to be "the evening star."

• Size is similar to Earth

• Its atmosphere is 96% Carbon dioxide, trapping heat and making the surface hot

  • Full of active volcanoes

• Takes 243 days to rotate around its axis

• Takes 225 days to go around the sun

The Inner Planets-Mars

• Smaller than Earth

• Has a core, mantle, crust, and thin atmosphere

• Has polar ice caps on the surface

• Takes two Earth Years to revolve around the sun

• Bright red color due to oxidation of iron-rich minerals in the crust

• Contains Methane in the Atmosphere

  • possibly from volcanoes that could melt ice caps and harbor microorganisms​

• Two small moons

  • Phobos

  • Deimos

Multiple Choice

The volcanos on this planet have caused it to have an atmosphere of 96% Carbon Dioxide

• Mercury

• Venus

• Mars

• Jupiter

• Saturn

Multiple Choice

At 10,000 degrees Celsius, hydrogen begins to change into helium and energy is released in a process called....

• supernova
• pulsar
• nuclear fusion
• nuclear fission

Multiple Choice

You can only see this planet close to sunrise or sunset

• Mercury

• Uranus

• Mars

• Jupiter

• Saturn

Multiple Choice

This is the inner-most layer of the sun, where nuclear fusion happens. 

• core
• corona
• photosphere
• chromosphere

Multiple Choice

This planet gets its color from the oxidized iron in the crust

• Mercury

• Mars

• Jupiter

• Saturn

• Venus

The Outer Planets-Jupiter

• The Largest of all the planets

  • diameter is 11 times the diameter of Earth

• rotates around its axis in 10 Hours

• Like the sun, some parts move at a faster rate than others

• Its atmosphere is 82% Hydrogen, 17% Helium, 1% other molecules

• Contains an ocean of liquid hydrogen that produces a strong magnetic field that captures particles from the solar wind

• Has at least 63 moons

  • Io & Europa are the size of our moon

The Outer Planets- Saturn

• The second-largest planet in the solar system

• Known for it's bright rings

  • Rings are frozen water and rocks that orbit around Saturn

• 47 moons

  • Largest is Titan

    • Shows some evidence of what Earth was like before life

• Surface Temperature is -170 degrees Celsius

The Outer Planets-Uranus

• Twice as far from Earth as Saturn

• Hard to see with the naked eye

• Has a very faint ring system

• Has at least 27 moons

The Outer Planets-Neptune

• Farthest planet from the sun

• 17 times the size of Earth

• has at least 13 moons

  • Triton: may be an object that just fell into orbit

    • Moves opposite the direction of the planet

  • Nereid

Multiple Choice

This planet has a faint ring system and is one of the farthest from the sun

• Uranus

• Mars

• Jupiter

• Saturn

• Neptune

Multiple Choice

This is the farthest planet from the sun

• Uranus

• Mars

• Jupiter

• Saturn

• Neptune

Multiple Choice

This is the largest planet in the solar system

• Uranus

• Mars

• Jupiter

• Saturn

• Neptune

Multiple Choice

This planet is known for it's large ring system

• Uranus

• Mars

• Jupiter

• Saturn

• Neptune

Asteroids & Comets

• Asteroids: the rocky remnants of the inner solar system

  • More than 150,000 exist in the asteroid belt​ between Mars and Jupiter

    • Larges known Asteroid, Ceres is more than 1000 km in diameter

  • Gravity from Jupiter causes collisions between asteroids that break them apart

• Comets: the icy Remnants of the outer solar system​

  • Frozen Ice mixed with dirt

  • Have an elliptical orbit and can pass by Earth multiple times before vaporizing

  • Tail leaves behind debris

  • Come from either the Kuiper Belt or the Oort cloud

Meteoroids

• Meteoroids: pieces of asteroids that are projected towards Earth

  • As they enter the atmosphere, they become meteors

  • If they are large enough to hit the surface, they are meteorites

Earth's Moon

• We know more about the moon than any other body in our solar system

• The moon is much smaller than Earth

  • Too small to have enough gravity to form an atmosphere

    • No weather on the moon

• The surface was once molten rock, but it cooled too quickly for tectonic plates to form, like on Earth

One side of the moon always faces us

• Recall: Every object exerts a gravitational pull on another object, and the distance between the objects changes the amount of pull

• One side of the Earth​ is closer to the moon, so it exerts more gravity on that side

  • As the moon moves around the Earth, the pull towards the closer side causes torque on the moon

    • It constantly aligns so it faces the Earth​

Phases of the Moon

• As Sunlight hits the moon's surface, only one half of the moon is illuminated at all times

• As the moon circles the Earth, the way light is seen on the Earth changes​ into different Moon Phases

  • ​Each cycle of the moon lasts 28 days

New Moon

• New Moon: The first Phase of the Moon's cycle

  • The sun is illuminating the far side of the moon, with no light hitting the ​ near side

  • We don't actually see the moon during this time

Waxing Phases of the Moon

• Waxing= increasing

• Waxing Crescent: The second Phase of the Moon's cycle

  • As the moon orbits the Earth, more sunlight hits the side of the Earth that faces the sun

• First Quarter: the Third Phase of the Moon's cycle

  • One half of the moon is illuminated and visible

  • The angle between the sun, the moon, and Earth is 90°

• Waxing Gibbous: The Third Phase of the Moon's cycle, When More than half of the moon is illuminated

Waning Phases of the Moon

​

• Full Moon: the Fourth Phase of the Moon's cycle, when the sunlight directly hits the side of the Moon that faces the Earth

• Waning Gibbous: The Fifth Phase, where more than half the moon is illuminated, but every day, less and less is illuminated

• Last Quarter: the sixth Phase of the Moon's cycle

  • One half of the moon is illuminated and visible

  • The angle between the sun, moon, and Earth is 90 Degrees

• Waning crescent: The final phase of the Moon's cycle

Solar Eclipses

• The sun is much larger than the moon, but is also farther away, so it looks like it is the same size

• Whenever the Earth, Sun, and Moon line up, an eclipse occurs

  • This happens every 18 months, but you can only see it if you are in the area that is facing the sun

• Solar Eclipse: The moon passes in front of the sun​ and blocks it out

  • occurs at a new moon​

  • Total darkness means a total eclipse

  • Lasts about 2-3 minutes

Lunar Eclipses

• Lunar Eclipse: The Earth passes in front of the moon​ and blocks it out

  • Usually follows a solar eclipse by two weeks

    • occurs at a full moon

  • The face of the moon is not completely dark because the Earth's atmosphere refracts light

Multiple Choice

A solar Eclipse occurs at this stage of the moon cycle

• New Moon

• First Quarter

• Full Moon

• Last Quarter

Multiple Choice

This word means increasing, and is used to describe the first half of the moon's cycle

• waxing

• waning

• growing

• gibbous

Multiple Choice

A lunar Eclipse occurs at this stage of the moon cycle

• New Moon

• First Quarter

• Full Moon

• Last Quarter

Multiple Choice

This word means decreasing, and is used to describe the second half of the moon's cycle

• waxing

• waning

• shrinking

• gibbous