Space Flashcards
(27 cards)
What objects make up our Solar System?
The Sun, eight planets, dwarf planets, moons, asteroids, and comets.
What is a natural satellite?
A moon that orbits a planet.
What is the name of our galaxy?
The Milky Way.
What are the rocky planets in the Solar System?
Mercury, Venus, Earth, and Mars.
What are the gas giants?
Jupiter, Saturn, Uranus, and Neptune.
Why do larger planets have rings?
Their strong gravitational field attracts debris.
Mnemonic for remembering the planets?
“My Very Early Morning Jam Sandwich Usually Nauseates”
(Mercury, Venus, Earth, Mars, Jupiter, Saturn, Uranus, Neptune).
What was the geocentric model?
The belief that Earth was at the center, and everything orbited around it in perfect circles.
What was the heliocentric model?
The correct model, where the Sun is at the center and planets orbit around it.
What evidence supported the heliocentric model?
Mars’ retrograde motion – it appears to move backward because Earth orbits faster.
Galileo’s observations – Moons orbiting Jupiter showed not everything orbited Earth.
Kepler’s discovery – Planets orbit in ellipses, not circles.
Why do planets stay in orbit?
The gravitational force from the Sun pulls planets in, causing them to move in a circular orbit.
Why do planets accelerate in orbit even though their speed remains constant?
Their velocity constantly changes direction, meaning they are always accelerating.
How does orbital speed change with distance from the Sun?
Closer to the Sun → Faster orbit (stronger gravity).
Farther from the Sun → Slower orbit (weaker gravity).
What happens if a planet moves closer to the Sun?
Gravitational attraction increases, so it moves faster to maintain a stable orbit.
What are the stages of a star’s life cycle?
Nebula – Cloud of gas and dust collapses due to gravity.
Protostar – Pressure increases, nuclear fusion begins.
Main Sequence Star – Equilibrium between gravity and fusion energy.
Red Giant / Red Supergiant – Expands as fuel runs out.
Final Stage:
Red Giant → White Dwarf → Black Dwarf (for smaller stars).
Supergiant → Supernova → Neutron Star OR Black Hole (for larger stars).
What process powers stars?
Nuclear fusion (Hydrogen → Helium), releasing large amounts of energy.
What causes a supernova?
A massive star collapses and explodes when it runs out of fuel.
What remains after a supernova?
Either a neutron star or a black hole (if the core is massive enough).
What is red shift?
The stretching of light waves from distant galaxies, making them appear redder.
What does red shift tell us?
Galaxies are moving away from us, meaning the universe is expanding.
How does red shift support the Big Bang Theory?
If galaxies are moving apart, they must have originated from a single point.
What are two key pieces of evidence for the Big Bang?
Red Shift – Shows the universe is expanding.
Cosmic Microwave Background Radiation (CMBR) – Leftover heat from the early universe.
What is cosmic microwave background radiation (CMBR)?
Radiation from the early universe, stretched into microwaves as the universe expanded.
What does CMBR prove?
The universe was once very hot and dense, supporting the Big Bang Theory.
