The Sun and our Solar System
-
Upload
jeanie-lacob -
Category
Education
-
view
717 -
download
0
Transcript of The Sun and our Solar System
Our Sun– A middle-aged, average
sized, Yellow star
– Made of mostly Hydrogen & Helium
– 99.8% of the mass in our Solar System
– 4.6 billion years old
– 93 million miles from the Earth
Our Sun• A giant sphere of hot glowing
gas, called plasma
• Shines because it is hot:– Surface Temp ~5500 C– Mostly Visible, UV & IR light
• Kept hot by nuclear fusion in its core:
– Builds Helium from Hydrogen fusion.
– Will shine for ~12 billion years
Sunspots• Dark areas on the Sun’s surface.• cooler than the surrounding area• The number of sunspots and location are
changing in a regular, 11 year cycle.
Solar flares
Powerful erruptions of particles that shoot into
space
The erupting particles strengthen the solar wind,
which is made of fast-moving gases that travel
through space.
Solar Wind
Fast moving gases that can travel in space
Solar Winds cause Auroras
The solar wind can disrupt radio waves and
cause auroras.
Aurora seen from space
Solar Prominence
A huge arc of gass that extends into
space
Energy from the Sun
4 hydrogen nuclei fuse to form 1 helium nucleus
Huge energy release
Nuclear FusionIn the early 1900’s, Albert Einstein discovered that matter and energy are interchangeable. Matter can be converted to energy as demonstrated by E = mc2 Where E is energy, m is mass and c is the speed of light.
Energy from the Sun
Uneven heating affects weather
Powers the water cycle
Energy from the Sun
Uneven heating causes winds
Provides energy for living things
producers
Life Cycle of Stars
A star forms from rotating
clouds and dust called a
nebula
1
Life Cycle of Stars
Gravity and other forces
cause the nebula to collapse.
Clouds begin to glow as the temperature
rises forming aProtostar
2
HL Tauri — a star system that is just being born.
The proto-planetary disk surrounding a young star 450 light-years away. The concentric rings cutting through the glowing gas and dust are tracks etched out by planets being spawned inside the disk.
baby planets forming around a star - Discovery News
Life Cycle of Stars
When gas pressure inside the star equals gravity, the star becomes stable and forms a
Main-sequence
Star
3
Nuclear fusion begins when the temperature reaches 10 million C
Life Cycle of Stars
The outer part of the star expands over time, while the core contracts forming a
Red Giant
4
Red giants are very bright, but cooler star.
Very large red giant stars are known as Super Giants.
Life Cycle of Stars
The outer layers of the star are released forming a
PlanetaryNebula
5
Life Cycle of Stars6
Over time the star shrinks forming a
WhiteDwarf
Life Cycle of Stars
Out of nuclear fuel, the star eventually fades into a
BlackDwarf
7
Life Cycle of Stars
Alternate Life Cycle of Huge Stars4
Very large red giants stars are known as Super Giants
Alternate Life Cycle of Huge Stars
5And
6
A Supernova is an explosion of a star accompanied by emission of radiation and light.
Alternate Life Cycle of Huge Stars7
Both cycles end with a Black Dwarf
Astronomy – the study of planets, our moon, stars (including our sun) and the universe.
Constellation – a group of stars that forms a pattern
Star chart – a map of the night sky
Chapter 7 Lesson 2 pages 246-251
The solar system is a small part of a much larger system called the Milky Way.
Your Parents’ Solar System
The Sun and the bodies that revolve around it make up the solar system.
Solar System Song
21st Century Solar System
Sun
Terrestrial Planets
Asteroid Belt
Jovian Planets
Kuiper Belt
Oort Cloud
The 21st Century Solar System
The Solar System: List of Ingredients
Ingredient
SunJupiterOther planetsEverything else
Percent of total mass
99.8% 0.1%
0.05% 0.05%
The Sun dominates the Solar System
Terrestrial Planets• Mercury, Venus, Earth & Mars
– “Earth-Like” Rocky Planets– Largest is Earth– Only in the inner solar system
• Rocky Planets:– Solid Surfaces– Mostly Silicates and Iron – High Density: (rock & metal)– Earth, Venus, & Mars have atmospheres
The Terrestrial Planets
Earth(1 M)
Mars(0.11 M)
Venus(0.82 M)
Mercury(0.055 M)
The Jovian Planets• Jupiter, Saturn, Uranus & Neptune
– Largest Planets: at least 15 times mass of Earth.– Only in the outer solar system (5 to 30 AU)– No solid surfaces (mostly atmosphere)– Low density
• Gas Giants: (Jupiter & Saturn)– Thick H/He atmosphere, liquid hydrogen mantle, ice core
• Ice Giants: (Uranus & Neptune)– Ice/rock core & mantle, thin H/He atmosphere
The Jovian Planets
Jupiter(318 M)
Uranus(15 M)
Saturn(95 M)
Neptune(17 M)
Dwarf Planets
• Defined by the IAU in 2006• Dwarf Planets:
– Ceres: first of the Asteroids, discovered in 1801– Pluto: trans-Neptunian object discovered in
1930– Eris: trans-Neptunian object discovered in 2005– Haumea (trans-Neptunian, suspected)– Makemake (trans-Neptunian, suspected)
Dwarf Planets
The Giant Moons
• Moon: any natural satellite orbiting a planet or dwarf planet
• Giant Moons:– Earth: The Moon (Luna)– Jupiter: Io, Europa, Ganymede, & Callisto – Saturn: Titan – has an atmosphere– Neptune: Triton – has an atmosphere
• Many smaller moons, both rocky & icy.• Only Mercury & Venus have no moons.
The Giant Moons
• Moon: any natural satellite orbiting a planet or dwarf planet
• Giant Moons:– Earth: The Moon (Luna)– Jupiter: Io, Europa, Ganymede, & Callisto – Saturn: Titan – has an atmosphere– Neptune: Triton – has an atmosphere
• Many smaller moons, both rocky & icy.• Only Mercury & Venus have no moons.
The Giant Moons
Pluto
TritonTitan
Callisto
Ganymede
Moon
Io
Europa
Mercury
Rhea
Iapetus
Titania
Oberon
Pallas
Vesta
Hygeia
Mimas
Enceladus
MirandaProteus
Ceres
Tethys Dione
Ariel Umbriel
Charon
Kuiper Belt
• Class of icy bodies orbiting beyond Neptune.– Found only in the outer Solar System (>30AU)– Astronomical Units, AU. One AU is the average
distance between the Earth and the Sun, 93 million miles, or 150 million kilometres.
• Examples:– Pluto & Eris (icy dwarf planets)– Kuiper Belt Objects (30-50AU)– Charon, Pluto’s large moon– Sedna & Quaor: distant large icy bodies
Kuiper Belt
Oort Cloud
• Spherical cloud of comets.– Extends out to almost 50,000 AU (1 light-year)– May contain trillions of comets– The outer edge is the farthest reach of the Sun’s
gravitational pull.– There are no confirmed observations – its
existence is theoretical only.
Oort Cloud
The Leftovers (small bodies)• Asteroids:
– Made of rock & metal (density 2-3 g/cc)– Sizes: Few 100km to large boulders– Most are found in the Main Belt (2.1-3.2 AU)
• Meteoroids:– Bits of rock and metal– Sizes: grains of sand to boulders
• Comets:– Composite rock & ice “dirty snowballs”– Longs tails of gas & dust are swept off them when
they pass near the Sun.
Asteroids
253 Mathilde 951 Gaspra 243 Ida
Meteor burning up in the atmosphere.
Comet P/Halley Comet P/Wilt
Is Pluto a Planet?
What to consider?• Size?• Shape?• Orbit?• What is it made
of?
IAU Definition of a PlanetIn 2006, the International Astronomical Union
(IAU) came up with the following definition of a planet: orbits the Sun has sufficient mass for its self-gravity to overcome
rigid body forces so that it assumes a hydrostatic equilibrium shape (i.e., it is spherical),
has cleared the neighborhood around its orbit, is not a satellite
IAU Definition of a Dwarf PlanetIn 2006, the International Astronomical Union
(IAU) came up with the following definition of a dwarf planet: orbits the Sun has sufficient mass for its self-gravity to overcome
rigid body forces so that it assumes a hydrostatic equilibrium shape (i.e., it is spherical),
has not cleared the neighborhood around its orbit, is not a satellite