The Solar System & Beyond

Chapter 11

Measuring Space Distance•Light Year –

the distance that light travels in one year –One light year is about 6 trillion miles

The Sun

• Our closest star

• Center of our solar system

• Made up of hydrogen and helium gases that produce light and heat through nuclear fusion

Inner Planets

•Terrestrial Terrestrial planets planets •Solid rocky Solid rocky corecore•Small in sizeSmall in size•Closest to the Closest to the sunsun•Earth is only Earth is only planet which planet which actually actually sustains lifesustains life

Mercury• The closest

terrestrial planet to the sun

• Smallest planet• Its revolution

around the sun takes 88 Earth days

• Does not rotate, only one side faces sun

• Temperature range -127ºF to 4027ºF

Venus• 2nd terrestrial planet

from the sun• Hottest planet• Has the densest

atmosphere• Brightest object in

the sky Oct. –Feb.• Revolution around

the sun is 224 Earth days long

• Rotates backwards

EarthEarth

• 3rd Terrestrial Planet From the Sun

• Only one that supports life

• Has weather and an amazing magnetic field

• Revolution 365 days

Mars• 4th planet from the

sun

• Nicknamed the red planet

• Revolves around sun every 434 Earth days

• Largest volcano in solar system is here: “Olympus Mons”

Jupiter• Largest gas giant• Largest planet• Revolution around

sun takes 11 ¾ Earth years

• Famous Red Spot is a never dying cyclone

• Takes 1300 earths to equal size

• 2nd biggest gravity pull in solar system

Saturn

• Famous for its icy rings of rocks and space dust

• 2nd largest planet• One revolution

around the sun takes 29 Earth years plus 155 days

• Temperature -140 C• Gas giant

Uranus• Spins on its side, its

poles, possibly due to planet collision

• Gas giant • No solid surface• One trip around the

sun takes 83 Earth years plus 273 days

• 2.7 light hours from the sun

Neptune

• Has belts of visible clouds

• Windiest planet in solar system

• The last of the gas giants

• Appears bright blue in telescope

• Revolves around sun every 163 Earth years

Pluto ?????• Farthest known

object from the sun, Bizarre Orbit

• Demoted from planet August 2006

• Believed to be a lost moon of Neptune

• Temperature -6900ºF• Revolves around sun

every 248 Earth Years

The Moon

• Our moon is a natural satellite – (a non-made man object that follows in a planets orbit)

• Moon is named Luna

• Moon revolves and orbits the Earth every 28 days. Sorry!

Our Place in Space ? ? ?Our Place in Space ? ? ?

• A Tiny Speck in the A Tiny Speck in the Milky Way GalaxyMilky Way Galaxy

• Solar SystemSolar System• Inside Asteroid BeltInside Asteroid Belt• Terrestrial PlanetTerrestrial Planet• Northern HemisphereNorthern Hemisphere• North AmericaNorth America• United StatesUnited States• AlabamaAlabama• MobileMobile

What’s Your Address?

How do we study space?

• Telescope – an instrument that collects electromagnetic radiation from the sky and concentrates it for better observation

Asteroids, Comets & MeteoritesAsteroids, Comets & Meteorites

This could be Earth in 2028! Are you Ready?

Small Bodies in the Solar SystemSmall Bodies in the Solar System

• Small bodies, the leftover “scraps” from the formation of the Solar System, fall into three distinct groups:Asteroids

• rocky or metallic in composition• most are located between the orbits of Mars and Jupiter

Asteroid

Asteroid – a rocky leftover planet fragment orbiting the Sun

Rocks Falling from the SkyRocks Falling from the Sky

meteor – a flash of light caused by a particle which enters Earth’s atmosphere.• most of these particles are the size of a pea• they completely burn up in Earth’s atmosphere

meteorite – a rock which is large enough to have survived its fall to Earth from space• they caused a brighter meteor…sometimes called a fireball

• How can you tell that you have a meteorite?– they have metal inside it – they may have holes, and may glow. . . So don’t

touch!

It’s not exactly shooting stars….its a meteor shower as it enters Earth’s sky.

If the rocks hit the ground it’s called a meteorite.

Comets

• comet – an icy leftover planet fragment orbiting the Sun

• may or may not have a tail

Comets• One of the most beautiful sights in the sky.• Throughout human history, these “hairy” stars would appear.

• like planets, they moved with respect to the fixed stars• unlike planets, they were not confined to the ecliptic and disappeared

after several weeks• They were taken as omens of good or bad fortune.

Recent Comets:

• 1986 Halley’s Comet

• 1996 Comet Hyakutake

• 1997 Comet Hale-Bopp

• Dozens per year too dim to be seen by eye

Hale-Bopp

Hyakutake

A Comet’s Journey

Comet Shoemaker-Levy 9• One by one, each fragment collided with Jupiter in July 1994.

• infrared cameras observed hot plumes ejected from the planet• material from deep inside Jupiter was ejected, and fell… left dark spots

• Such impacts probably occur on Jupiter once every 1,000 years.

This was a reminder to us that impacts still occur in the present!!

Impacts and Mass Extinctions on Earth• We have a plausible scenario of how the impact led to mass extinction.

• debris in atmosphere blocks sunlight; plant die…animals starve

• poisonous gases form in atmosphere

PAST FUTURE ?