Solar system Flashcards
What is the composition of iron meteorites?
iron-nickel alloy
What is the composition of stony meteorites?
Made of silicate minerals including olivine, pyroxene and plagioclase feldspar
What is the composition of carbonaceous chondrites?
water and organic compounds (type of stony)
Where are iron meteorites thought to originate from?
Thought to represent the core of a planet like-object from the early solar system.
Where are stony meteorites thought to originate from?
Thought to represent the mantle of a small planet-like object from the early history of the solar system
Meteorites
Rock fragments which fall to earth from space
Where do most meteorites come from in space?
Asteroid belt
What are the pieces of evidence for the impact of meteorites on earth? 5
Craters are circular Quartz grains shocked or melted Rock strata tilted by impact Material at base is brecciated Ejected material falls back to earth in an inverted sequence
What are the two types of planets in our solar system?
Terrestrial
Gas giants
Name the terrestrial planets
Mercury, Venus, Earth, Mars
Name the gas giants
Jupiter, Saturn, Uranus and Neptune
What are terrestrial planets?
They are made up of rock and have a dense core
What are gas giants?
They are made entirely of gases and are much larger than the terrestrial planets
Planet
A sizeable object orbiting a star, massive enough to have its own gravity
Which planets does the asteroid belt occur between?
Mars and Jupiter
Moon
A natural satellite that orbits a planet
How old is the earth?
4.6 billion years
Asteroids
Rocky objects which failed to form a planet
Comet
Composed of ice and dust. The outer layer melts into water vapour as it gets closer to the sun
Sun
A star composed of hydrogen and helium
Solar system
Consists of the sun, planets, moons, asteroids and comets
What is the Big Bang?
An event that led to the formation of the solar system about 14 billion years ago. It was the point when all matter and energy were created. At that moment all matter was compressed into a space billions of times smaller than an atom. Both time and space where set to zero.
When was the solar system believed to have been formed?
4500 million years ago
Describe how the solar system formed?
A giant cloud of dust collapsed (nebular hypothesis) - possibly when it was hit by a shock wave from a nearby supernova. The material was drawn together by gravity and built up over time eventually forming a rotating disc which ignited triggering nuclear reactions and formed the sun. Other material in the rotating disc began to stick together (accretion) and formed progressively larger objects called planetesimals until they finally resulted in planets.
