Physics - Space And Beyound Flashcards
What is the solar system made up of?
The Sun and anything that goes round it (orbit)
The solar system consists of 8 planets, dwarf planets, and other celestial objects.
How many planets are in the solar system?
8 planets
Includes dwarf planets like Pluto.
What defines a planet?
An object that orbits a star (the Sun)
Dwarf planets do not fit the standard definition of a planet.
What is a dwarf planet?
An object that orbits a star but is too small to be a planet or does not fit the planet pattern
Pluto is an example of a dwarf planet.
What are moons also known as?
Natural satellites
Moons orbit planets.
What are artificial satellites?
Satellites that humans have built
They mostly orbit the Earth.
What is a nebula?
A cloud of dust and gas from which stars are formed
Nebulae are the initial stage in star formation.
What is a protostar?
A stage in star formation where gravity pulls dust and gas together
This is the initial collapse of a nebula.
What occurs during the main sequence star stage?
Hydrogen fusion starts, emitting a lot of energy
This stable phase lasts for a few billion years.
What happens when hydrogen in a star begins to run out?
The star becomes a red giant or a red super giant
The transition depends on the size of the star.
What is the final stage of a red giant?
It becomes a white dwarf, then cools to become a black dwarf
The outer layers of dust and gas are expelled.
What happens to a red super giant at the end of its life cycle?
It explodes into a supernova
This explosion can lead to the formation of a black hole.
What force causes planets and satellites to circle an object?
Gravity
Gravity acts towards the center of the orbit.
True or False: The speed of an object in orbit changes.
False
The direction changes, but the speed remains constant.
What must happen for an orbit to remain stable if speed changes?
The radius must change
The closer an object is to another, the quicker it must travel.
What provides evidence for the expanding universe?
Redshift
Distant galaxies show increased wavelengths as they move away.
What does redshift indicate?
Light has shifted towards the red end of the spectrum
It is associated with galaxies moving away from us.
How do scientists visualize the expanding universe?
Dots on a balloon moving away from each other as it is blown up
This analogy helps illustrate the concept of expansion.
What is dark mass and energy?
Unknown entities that scientists have discovered but do not fully understand
They are significant components of the universe.
What is the Big Bang theory?
A theory about how the universe began with a dense state that exploded 13.7 billion years ago
It explains the expansion of the universe.
What does the observation of supernovae since 1998 suggest?
Distant galaxies are moving away faster
This supports the Big Bang theory.
