Lecture 3 Flashcards
Solar Nebular Disk Model
States that the sun, the planets and all other objects in the solar system formed from nebulous material billions of years ago. Currently accepted paradigm of solar system formation.
Nebula
Enormous cloud of dust and gas occupying the space between stars and acting as a nursery for new stars.
Supernova
Massive explosion triggered by a star. One of the final stages in the lifecycle of a star
Protostar
The very earliest stage of star formation.
Star
Any massive self luminous celestial body of gas that shines by radiation derived from its internal energy sources
Accretion
Objects being formed by many smaller pieces brought together
Planetesimal
Objects formed by accretion which are large enough to generate their own gravity (1km in size or greater)
Solar winds
Waves of charged particles (electrons, protons and others). Interact with other atoms and structures in the developing solar system.
Frost line
At a certain distance from the sun, the suns heat is no longer enough to vaporize or melt water (water freezes)
Inner core
Solid ball, currently believed to be composed mainly of iron and nickel
Outer core
A liquid layer composed mainly of iron and nickel
Lower mantle
Composed mainly of rock
Upper mantle
Composed mainly of rock
Crust
A very thin layer; where life exists on the planet
Plate tectonics
The movement of portions of the crust and upper mantle of the Earth.
Responsible for the movement of continents, generation of new crust, recycling or old crust.
Earth is the only planet that we know of that has plate tectonics.
Late Heavy Bombardment
A large number of asteroids collided with the planets in the inner solar system
Rare earth
Earth is truly rare; there are only a few planets with complex life per galaxy
Habitable zone
A distance from the central star where liquid water and gaseous CO2 can exist
Radiometric dating
A method used to determine how old an object is by measuring the amount of radioisotope the object contains against the decay product it contains
Relative-age dating
The process of determining if one rock or geologic event is older or younger than another, without knowing their specific ages
Determining the relative order of past events, without determining their absolute age
Carbon dating
Measuring the age of a once living thing by measuring the amount of carbon inside of it
Half-life
The time needed for a quantity of a substance to reduce by half of its initial value
