P16: Space Flashcards
What do dwarf planets orbit?
The Sun
What are the natural satellites?
The moons that orbit planets
How was the sun formed?
From a cloud of dust (nebula) pulled together by gravitational attraction
What determines a star’s life cycle?
The size of the star
How are naturally occurring elements produced?
Fusion processes in stars
What is produced in a supernova?
Elements heavier than iron
What distributes the elements throughout the universe?
The explosion of a supernova
What is the function of gravity for planets?
It provides the force that allows planets and satellites to maintain their circular orbits
What can gravity do for circular orbits?
It can lead to changing velocity but unchanged speed
What must change if the speed stable orbits change?
Radius
How is a protostar formed?
The big cloud of dust and gas (nebula), is pulled together due to the attractive force of gravity
What happens as the protostar is squeezed?
It becomes more dense, allowing particles to collide more often, increasing the temperature and pressure
What allows the main sequence star to stay in a long period of time?
The outward pressure from energy from nuclear fusion and the inward pressure by gravity
What causes a white dwarf from the red giant?
The expelling of outer layers of dust and gas.
Describe the white dwarf.
Hot, dense and solid
What causes a black dwarf?
The white dwarf becoming cooler and darker due to it emitting all its energy
What would be the product of a very big supernova?
A neutron star, which is a dense core
What would be the product of a massive supernova?
A black hole.
Where does black hole get its name from?
The fact that its so dense that the gravity can pull in any light that passes nearby, meaning they appear as empty spaces.
What are asteroids made of?
Mostly rock and metal, between mars and venus
What are comets?
Mostly ice and dust, with eliptical orbits
What is a galaxy?
A collection of billions stars
What is an orbit?
The curved path of one celestial object with another
What results to a steady orbit?
Instantaneous velocity of the orbiting object and the gravitational pull of the orbited object
What is instantaneous velocity?
The velocity of an object at a single moment or point in time
How does the red-shift provide evidence for the Big Bang Theory?
If the universe is expanding, it makes sense that it started smaller, hence a single spot
What keeps the sun’s core hot?
The energy from fusion reactions
What causes the formation of a red giant?
When the hydrogen runs out from the main sequence star, and the star cools and expands. The outward force of pressure is larger than the inward.
What do larger stars fuse hydrogen nuclei into?
Lithium and other lighter elements
What is dark matter and dark energy?
An unknown substance that holds galaxies together but does not emit electromagnetic radiation. Dark energy is the thing that causes the universe to expand quickly
