Origin of our Universe:Planets and Things

OUTCOME QUESTION(S):

S1-4-08:What objects make up our solar system and Universe?

Vocabulary and PeopleAsteroid belt Kuiper belt Oort cloudMoon Asteroid Meteoroid MeteorMeteorite Comet

Terrestrial planets(inner planets)

Closest to the Sun• Receives sunlight 10x brighter than Earth• Day temperatures over 400°C No atmosphere - so night temp fall to -180°C• Day (rotation) – 59 Earth days • Year (revolution) – 88 Earth days

Mercury

It rotates so slowly that its “year” is less than 2 “days” long

3rd brightest object in the sky • CO2 atmosphere traps heat (+ 465°C)• Many volcanoes eject tonnes of sulphur Clouds of sulphuric acid – makes acid rain• Day (rotation) – 243 Earth days • Year (revolution) – 225 Earth days

Venus Sun and Moon are brightest objects

Its “year” is shorter than its “day”

Atmosphere (N2, O2, H2O) stabilizes temperature• Ranges from -85oC to +65oC Liquid water covers about 70% of surface• Generally stable – some volcanoes, earthquakes• Day (rotation) – 1 Earth days • Year (revolution) – 365 1/4 Earth days

Earth

Distance from the Sun is most responsible for the factors that contribute

to Earth’s ability to sustain life

Bright red - iron oxide dirt makes it reddish• Most studied planet (no signs of life… yet ) Of all planets, Mars is most like Earth• Surface temp ranges from -120oC to +30oC • Day (rotation) – 1 Earth day • Year (revolution) – 687 Earth days

Mars

Although it is dry and barren now, scientists have evidence that may

point to past glaciers and liquid water

An Asteroid Belt separates the Terrestrial planets from the Gas Giants – maybe

remains of a totally smashed older planet

The Gas Giants(outer planets)

Look at the shadow of a moon on the picture of Jupiter

Largest of the planets (11x bigger than Earth).• Has 63 moons (2006) Great Red Spot is a continuous hurricane• Temp around -160oC• Day (rotation) – 10 Earth hours • Year (revolution) – 11.9 Earth years

Jupiter

The coloured bands are gas clouds being streaked over

the surface as it rotates quickly

• 2nd largest of the planets Least dense – may not have a solid core Rings stretch from Earth to Moon• 60 moons and 1000 rings (could be crushed moon)• Day (rotation) – 11 Earth hours • Year (revolution) – 29.5 Earth years

Saturn

Notice the coloured bands on the surface here too

3 moons and a shadow in this picture

Rotates on its side• Extremely cold -210oC Has several narrow, dark rings• Has 27 moons• Day (rotation) – 17 Earth hours • Year (revolution) – 84 Earth years

Uranus

It is now pronounced “ur-an-is” not “ur-anus”

• Only discovered because its gravity “tugs” on Uranus’s orbit causing changes

Blue and white – methane in atmosphere The Great Dark Spot is a gigantic storm• Extremely cold -220oC• Day (rotation) – 16 Earth hours • Year (revolution) – 165 Earth years

Neptune

Neptune has some faint rings too, and 20 moons

Kuiper Belt and the Oort Cloud• Contain thousands of icy and rocky objects • Kuiper – from Neptune to about 30 to 55 AU• Oort Cloud – from 5000 AU to 100000 AU Pluto and Eris are the best known dwarf planets found in Kuiper belt

Pluto was reclassified as a dwarf planet in

2006

Moon: Large natural object (rock/metals) that revolves around a planet – also called a satellite.

The Roman goddess of the moon was Luna

Planet (2006) Known moonsMercury 0

Venus 0Earth 1Mars 2

Jupiter 63Saturn 60Uranus 27

Neptune 13Pluto 3

Humans have visited the moon’s surface six times between 1969 and 1972.

• 1st- Soviet Luna 2 (1959)• 2nd brightest object in sky• No atmosphere• ¼ diameter of Earth

Asteroid: Chunk of rock/metal that orbits the Sun but too small to be planet – minor planets.

The fear is that a Trojan passes close enough to get

pulled in by Earth’s gravity and collide

• Asteroid belt in large gap from Mars – Jupiter• Largest is 1000 Km in diameter

• Asteroid that crosses with Earth called Trojan

Meteoroid: lump of rock that is trapped by Earth’s gravity and pulled into the atmosphere.

The only difference between meteoroid and asteroid is that a meteoroid is random and an asteroid orbits the Sun

Falling meteoroids bump into air molecules heating up (friction) until the air glows – and the meteoroid burns up

and breaks apart.

• Meteoroid that completely burns up - meteor• producing a streak of light - shooting star

Meteorite: fragment of a meteoroid that doesn’t burn up and strikes the Earth (space rock).

• Large meteorites collisions make craters• Westhawk Lake is a crater

Meteorite impact crater in Arizona

Comet: chuck of ice/dust that orbits the Sun. • Most originate from the Oort cloud

• Tail: passing by Sun heats trailing gas and debris then blown out by solar wind - millions of km long

• Some have regular periods of revolution

Halley’s comet: last seen in 1986 it has a period of 76 years

CAN YOU ANSWER THESE QUESTIONS?

S1-4-08:What objects make up our solar system and Universe?

Vocabulary and PeopleAsteroid belt Kuiper belt Oort cloudMoon Asteroid Meteoroid MeteorMeteorite Comet