the solar system. terms ecliptic –imaginary plane within which the 8 major planets orbit the sun...

The Solar System

Terms• Ecliptic

– Imaginary plane within which the 8 major planets orbit the Sun

– Apparent path of Sun across the sky as seen from Earth

PSCI 131: The Solar System

Terms: EclipticPSCI 131: The Solar System

From: Wikipedia.org

The Solar System• The Early Solar System• Overview• The Terrestrial Planets• The Jovian Planets• Dwarf Planets• Asteroids• Comets• Meteoroids

PSCI 131: The Solar System

The Early Solar System

The Early Solar SystemPSCI 131: The Solar System – The Early Solar System

From: jcconwell.wordpress.com

The Nebular Theory

The Early Solar SystemPSCI 131: The Solar System – The Early Solar System

Planets formed from collisions of smaller objects

The Nebular Theory

Solar System Overview

Overview of the Solar System• Sun: >99% of solar system’s mass

• Major planets– 4 terrestrial– 4 Jovian

• Dwarf planets– 5 recognized so far by IAU

PSCI 131: The Solar System – Overview

Overview of the Solar System• Asteroids, comets, meteoroids

– Leftover material from solar system formation– Fragments from collisions

• Dust, gas, radiation

PSCI 131: The Solar System – Overview

The 8 Major Planets

What Is A Major Planet?

• Spherical

• Orbits Sun

• Not a moon

• Has cleared its orbital path of other objects

PSCI 131: The Solar System

Major Planets and SunPSCI 131: The Solar System – The 8 Major Planets

The major planets, shown to scale

The Four Terrestrial Planets• “Terrestrial”: Earth-like• Mercury, Venus, Earth, Mars

PSCI 131: The Solar System – Terrestrial Planets

The terrestrial planets, shown to scale

From: wikipedia.org

The Four Terrestrial Planets

• Small• Rocky• Dense• Thin atmospheres• Short years• Long days• Main heat source: Sun

PSCI 131: The Solar System – Terrestrial Planets

EARTH VENUS

MARS MERCURY

From: wikipedia.org

MercuryPSCI 131: The Solar System – Terrestrial Planets

From: wwu.edu

From: wikipedia.org From: wikipedia.org

• Orbital period: 88 days

• Rotation period: 59 days

• Temp range: -270° F – 870° F

• Atmosphere: None

Venus

PSCI 131: The Solar System – Terrestrial Planets

Cloud cover of Venus.

From: ircamera.as.arizona.edu

Surface of Venus, photographed with cloud-penetrating radar. From: annesastronomynews.com

• Orbital period: 225 days

• Rotation period: 243 days

• Temperature: 900° F

• Atmosphere: 97% CO2

Earth

PSCI 131: The Solar System – Terrestrial Planets

Earth from low-altitude orbit.

From: astexhibits.com

Earth as seen from the Moon.

From: science1.nasa.gov

• Orbital period: 365.25 days

• Rotation period: 23 hr 56 min

• Temperature: 58° F (2012 average)

• Atmosphere: Nitrogen, oxygen, argon, water, CO2

Mars

PSCI 131: The Solar System – Terrestrial Planets

Mars from low-altitude orbit, showing atmosphere.

From: wikipedia.org

• Orbital period: 687 days

• Rotation period: 24 hr 37 min

• Temperature: -80° F (average)

• Atmosphere: Thin, CO2

MarsPSCI 131: The Solar System – Terrestrial Planets

Volcanoes and water ice clouds on Mars.From: jpl.nasa.gov

Olympus Mons volcano

Olympus Mons. Cliff at base is 5 miles high. Inset shows height compared to Earth mountains.From: wikipedia.org

The Four Jovian Planets• “Jovian”: Jupiter-like• Jupiter, Saturn, Uranus, Neptune

PSCI 131: The Solar System – Jovian Planets

The Jovian planets, shown to scale

From: cseligman.com

The Four Jovian Planets

• Large• Gas & ice• Low density• Long years• Short days• Main heat source: internal (from gravitational

compression)

PSCI 131: The Solar System – Jovian Planets

Jovian planets compared to the Sun and Earth (far right) Modified from: wikipedia.org

JupiterPSCI 131: The Solar System – Jovian Planets

Jupiter as it would look if it were the same distance from Earth as the Moon.

From: tholtz.com

• Orbital period: 12 years

• Rotation period: 9 hr 56 min

• Temperature: -234° F (cloud tops)

• Atmosphere: Hydrogen, helium

From: photojournal.jpl.nasa.gov

Jupiter’s Atmosphere

PSCI 131: The Solar System – Jovian Planets

Cross-section of Jupiter compared with Earth. 125°K is about -234°F; 2000°K is about 3100°F.

• Mostly H and He

• Would have become a sun if it had been bigger

• Pressure within atmosphere is high enough to make liquid and metallic hydrogen

Jupiter: The Great Red SpotPSCI 131: The Solar System – Jovian Planets

High-res photo of the Great Red Spot, an ancient storm the size of three Earths.

SaturnPSCI 131: The Solar System – Jovian Planets

Saturn imaged by the Cassini-Huygens spacecraft, 2008. From: nasa.gov

• Orbital period: 30 years

• Rotation period: 10 hr 30 min

• Temperature: -288° F (cloud tops)

• Atmosphere: Hydrogen, helium

Saturn’s rings and Earth, taken by Cassini-Huygens spacecraft, 2008. From: nasa.gov

Earth as seen from Saturn

Saturn’s Moon TitanPSCI 131: The Solar System – Jovian Planets

Comparison of Titan with Earth and Earth’s moon.

• Atmosphere: Nitrogen, methane

•Only moon known to have an atmosphere

• Bodies of stable liquid on surface

•Methane, ethaneTitan’s surface. From: nasa.gov

• Orbital period: 84 years

• Rotation period: 17 hr 14 min

• Temperature: -357° F (cloud tops)

• Atmosphere: Hydrogen, helium, frozen ammonia and methane

•Rotates on its side:

UranusPSCI 131: The Solar System – Jovian Planets

Uranus showing rings and cloud

bands. From: nasa.gov

Axis

• Orbital period: 165 years

• Rotation period: 16 hr 7 min

• Temperature: -392° F (cloud tops)

• Atmosphere: Hydrogen, helium, frozen ammonia and methane

NeptunePSCI 131: The Solar System – Jovian Planets

Neptune with cloud bands, cirrus clouds (white) and storm systems (dark spots). From: nasa.gov

The Dwarf Planets

PSCI 131: The Solar System

What Is A Dwarf Planet?

• Spherical

• Orbits Sun

• Not a moon

• Has NOT cleared its orbital path of other objects

PSCI 131: The Solar System

Five Recognized Dwarf Planets(Listed in order of decreasing size)

• Eris• Pluto• Makemake• Haumea• Ceres

• All are located in “debris belts”

PSCI 131: The Solar System – Dwarf Planets

Debris Belt LocationsOrbit of Earth

Orbit of MarsASTEROID

BELT

SUN

KUIPER BELT

Orbit of Uranus

Orbit of Neptune

Debris Belt Locations

ASTEROID BELT

KUIPER BELT

Orbit of Uranus

Orbit of Neptune OORT CLOUD

Five Recognized Dwarf Planets

• Eris: Kuiper Belt• Pluto: Kuiper Belt• Makemake: Kuiper Belt• Haumea: Kuiper Belt• Ceres: Asteroid Belt

• Oort Cloud: No recognized dwarf planets; trillions of comets

PSCI 131: The Solar System – Dwarf Planets

The Smaller Objects: Asteroids, Comets, &

Meteoroids

PSCI 131: The Solar System

Asteroids• Size: 10s to 100s of miles

• Shape: Irregular

• Composition: Rock, metal

• Atmosphere: None

• Location: Mostly in Asteroid Belt between Mars and Jupiter

PSCI 131: The Solar System – Smaller Objects

(doesn’t look like this)

PSCI 131: The Solar System – Smaller Objects

The Asteroid Belt

What Does the Asteroid Belt Look Like?

PSCI 131: The Solar System – Smaller Objects

It’s mostly empty space

Asteroids: Earth CrossersPSCI 131: The Solar System – Smaller Objects

Comets• Size: average diameter about 5 miles

• Shape: Irregular

• Composition: Ice, rock & metal fragments

• Atmosphere: None

• Location: Kuiper Belt & Oort Cloud

PSCI 131: The Solar System – Smaller Objects

Halley’s Comet, 1986

From: dailygalaxy.com

CometsPSCI 131: The Solar System – Smaller Objects

Structure of a comet

CometsPSCI 131: The Solar System – Smaller Objects

A comet’s coma and tail only form near the Sun. The tail always points away from the Sun.

CometsPSCI 131: The Solar System – Smaller Objects

Comet Shoemaker-Levy struck Jupiter in 1994.

Meteors• Size: sand grain

(average)

• Composition: Rock, metal

PSCI 131: The Solar System – Smaller Objects

Meteors• Meteor: within a planet’s atmosphere

• Meteorite: has struck the ground

• Meteoroid: still in space

PSCI 131: The Solar System – Smaller Objects

The Chelyabinsk “Meteor”, February 15, 2013

• Approx. mass: 11K tons • Approx. size: 60 ft• Velocity: 41K mph• Altitude of airburst: 76K feet• Energy: 500K tons of TNT• Injuries: 1,491• Damage: 7,200 buildings

PSCI 131: The Solar System – Smaller Objects

VIDEO: Chelyabinsk meteor airburst and building damage