P2- Space Physics Flashcards
(42 cards)
How many stars does our solar system have?
1
What is the 1 star in our solar system?
The Sun
What is the solar system?
All the stuff that orbits the sun
4 things that orbit the sun
1) Eight Planets
2) Dwarf planets
3) Moons
4) Artificial satellites
What are planets?
-Large objects that orbit a star
-Their gravity is strong enough to have pulled in any nearby objects apart from their natural satellites
The Terrestrial Planets
-First 4 planets: Mercury, Venus, Earth, Mars
-All made up of rock and metal
-Denser than Jovian planets
-Substantially smaller than the gas giants
Asteroid belt
-Lies between the orbits of Mars and Jupiter
-Made up of thousands of small rocks and ices
The Jovian Planets
-Last 4 planets: Jupiter, Saturn, Uranus, Neptune
-Mainly made of hydrogen and helium in gas form
-Less dense
-Have many moons orbiting them
What are dwarf planets?
Planet-like objects that orbit stars but don’t meet all the rules of being a planet
What are moons?
A type of natural satellite that orbits planets
What is the Milky Way?
-A massive collection of billions of stars held together by gravity
-Our solar system is a tiny part of the Milky Way galaxy
How was the sun formed?
A cloud of dust and gas (nebula) was pulled together by gravitational attraction
Simple life cycle of a star that is about the same size as the sun
Cloud of gas and dust (nebula) -> Protostar -> Main sequence star -> Red giant -> White dwarf -> Black dwarf
Simple life cycle of a star that is much bigger than the sun
Cloud of gas and dust (nebula) -> Protostar -> Main sequence star -> Red super giant -> Supernova -> Neutron Star OR Black hole
What is the life cycle of a star determined by?
The size of the star
Step 1 of the life cycle of a star (Prompt: Cloud)
Stars initially form a cloud of dust and gas called a nebula
Step 2 of the life cycle of a star (Prompt: Gravity)
-Force of gravity pulls the dust and gas together to form a protostar
-Temp rises as the star gets denser
-When temp is high enough, hydrogen nuclei undergo nuclear fusion to form helium nuclei giving huge amounts of energy, keeping the core of a star hot
Step 3 of the life cycle of a star (Prompt: Pressure)
-Long stable period where outward pressure caused by the nuclear fusion that tries to expand the star, balances the force of gravity pulling everything inwards
-In this stable period, it is called a main sequence star lasting several billion years
Step 4 of the life cycle of a star (Prompt: Hydrogen)
-Hydrogen begins to run out
-Star swells into either a red giant or a red super giant
-Surface cools so it becomes red
-Fusion of helium occurs
Step 5 of the life cycle of a star (Prompt: Unstable) (stars about the same size as the sun)
-Small to medium sized star like the sun becomes unstable, ejecting its outer layer of dust and gas
-Leaves behind a hot, dense, solid core called a white dwarf
Step 6 of the life cycle of a star (Prompt: Energy) (stars about the same size as the sun)
-As white dwarf cools down, it emits less and less energy
-When it no longer emits a significant amount, it is called a black dwarf
Step 5 of the life cycle of a star (Prompt: Elements) (stars much bigger than the sun)
-Big stars glow brightly again
-Undergo more fusion and expand and contract several times
-Form elements as heavy as iron in various nuclear reactions
-Eject these elements into the universe to form new planets and stars
-Stars and their life cycles produce and distribute all naturally occurring elements
Step 6 of the life cycle of a star (Prompt: Dense core) (stars much bigger than the sun)
-Exploding supernova throws outer layers of dust and gas into space leaving a very dense core called a neutron star
-If the star is massive enough, it becomes a black hole
What is a satellite?
Any celestial object orbiting the Earth or any other planet
