Space Flashcards
What are the main objects in our Solar System?
Sun - 8 planets - dwarf planets - moons - asteroids - comets
What kind of object is the sun?
Star
What galaxy is our solar system in?
The Milky Way
What do all stars start off as?
Huge cloud of gas and dust called a nebula
Which force is responsible for forming a protostar from a nebula?
Gravity
What kind of reaction causes the expansion of a star?
Nuclear fusion
How does a main sequence star remain stable?
Fusion reactions produce outwards forces which balance the gravitational forces pulling it inwards
What determines the life cycle of a star?
Mass
What is the life cycle of a star with about the same mass as the sun?
Protostar - main sequence star - red giant - white dwarf - black dwarf
What is the life cycle of a star with much more mass than the sun?
Protostar - main sequence star - red supergiant - supernova - neutron star or black hole (if mass big enough)
How are naturally occurring elements formed?
From nuclear fusion during the life cycle of stars
Which elements are only produced in a supernova?
Elements heavier than iron
How are the elements distributed throughout the universe?
Massive stars going supernova (exploding)
How does the force of gravity make objects in orbit change their velocity but not their speed?
Gravity provides a centripetal force which keeps orbiting objects moving in a circle - they are constantly changing direction
To change the speed of an object in stable orbit, what factor must change?
Radius of the orbit
What is red-shift?
Wavelengths of light get longer if the light source is moving away from the observer
What evidence suggests that the universe is expanding?
Light from more distant galaxies is more red-shifted, so more distant galaxies are moving away faster
What is the name of the scientific theory for the origin of the universe that suggest it started off as an extremely small, hot, and dense region?
The Big Bang Theory
