Space physics Flashcards
How many galaxies are in the universe?
Hundreds of millions
What is the name of the galaxy we live in?
Milky Way
What are the smaller rocky planets in our solar system?
Mercury, Venus, Earth, and Mars
What are the gas giants in our solar system?
Jupiter, Saturn, Uranus, and Neptune
How can you remember the order of the planets in our solar system?
My - Mercury
Very - Venus
Educated - Earth
Mother - Mars
Just - Jupiter
Served - Saturn
Us - Uranus
Noodles - Neptune
What is the natural satellite of Earth?
The moon
What are comets and asteroids in relation to the sun?
They are objects that orbit the Sun, often with elliptical orbits
Where did our Sun originate from?
From a nebula, a massive cloud of dust and gas
What happens to particles in a nebula due to gravity?
They are attracted to one another, losing potential energy and gaining kinetic energy
What is a protostar?
A stage in stellar evolution where a star is forming from a nebula
What is the main-sequence phase of a star?
It is the stable phase where a star spends about 95% of its life
What occurs during the main-sequence phase of a star?
There is an equilibrium between gravity pulling inward and nuclear fusion pushing outward
What happens to a low to medium mass star at the end of its life?
It expands into a red giant and then shrinks into a white dwarf
What is a red giant?
A stage in stellar evolution where a star expands and cools while fusing heavier elements
What is a white dwarf?
A small, hot remnant of a star that has exhausted its nuclear fuel
What is a black dwarf?
A theoretical stage where a white dwarf has cooled down completely
What happens to a massive star at the end of its life?
It becomes a red supergiant and may end in a supernova explosion
What happens to a massive star at the end of its life?
It becomes a red supergiant and may end in a supernova explosion
What is a supernova?
A massive explosion that occurs at the end of a massive star’s life
What is a neutron star?
A dense core left after a supernova where protons and electrons combine to form neutrons
What is a black hole?
A region in space where gravity is so strong that not even light can escape
How do we observe black holes?
We can only see their effects on nearby objects, not the black holes themselves
What role does gravity play in the universe?
It pulls objects together, allowing fusion to take place and keeping planets in orbit
How are new elements created in stars?
Through the process of nuclear fusion of light nuclei
Where are elements heavier than iron believed to be created?
In supernova explosions
What happens to elements after a supernova?
They are distributed throughout the universe, potentially forming new nebulae and stars
How do planets and satellites remain in orbit?
Due to the gravitational force exerted by the Sun
What happens to a comet’s speed as it approaches the Sun?
It moves faster as it loses potential energy, converting it to kinetic energy
What is redshift in relation to the universe’s expansion?
It is the phenomenon where light from distant stars appears stretched, indicating the universe is expanding
What evidence supports the Big Bang theory?
The observation of redshift in light from distant galaxies
How old is the universe estimated to be?
About 13.8 billion years
What has been observed about the rate of the universe’s expansion in recent years?
It is getting faster and faster
What are some possible explanations for the accelerated expansion of the universe?
Dark matter or dark energy may be driving this rapid inflation
What are the key components of the solar system?
- The Sun
- Eight planets: Mercury, Venus, Earth, Mars, Jupiter, Saturn, Uranus, Neptune
- Moons orbiting planets
- Comets and asteroids orbiting the Sun
What are the stages of stellar evolution for low and medium mass stars?
- Nebula
- Protostar
- Main-sequence star
- Red giant
- White dwarf
- Black dwarf
What are the stages of stellar evolution for high mass stars?
- Nebula
- Protostar
- Main-sequence star
- Red supergiant
- Supernova
- Neutron star or black hole
What evidence supports the Big Bang theory?
- Redshift of light from distant galaxies
- The universe’s expansion
- Estimated age of the universe (13.8 billion years)
Explain the stages of a neutron star/black hole:
- A star forms from massive clouds of dust and gas in space, also known as a nebula. Nebulae are mostly composed of hydrogen.
- As the mass falls together it gets hot. A star is formed when it is hot enough for the hydrogen nuclei to fuse together to make helium. The fusion process releases energy, which keeps the core of the star hot.
- During this stable phase in the life of a star, the force of gravity holding the star together is balanced by higher pressure due to the high temperatures. The Sun is at this stable phase in its life.
- A larger star with more mass will go on making nuclear reactions, getting hotter and expanding until it explodes as a supernova.
- Depending on the mass at the start of its life, a supernova will leave behind either a neutron star or a black hole.
explain the stages of a black dwarf star:
- A star forms from massive clouds of dust and gas in space, also known as a nebula. Nebulae are mostly composed of hydrogen.
- As the mass falls together it gets hot. A star is formed when it is hot enough for the hydrogen nuclei to fuse together to make helium. The fusion process releases energy, which keeps the core of the star hot.
- During this stable phase in the life of a star, the force of gravity holding the star together is balanced by higher pressure due to the high temperatures. The Sun is at this stable phase in its life.
- When all the hydrogen has been used up in the fusion process, larger nuclei begin to form and the star may expand to become a red giant
- When all the nuclear reactions are over, a small star like the Sun may begin to contract under the pull of gravity. In this instance, the star becomes a white dwarf.
- As the white dwarf cools down, it emits less energy. When it no longer emits a significant amount of energy, it is called a black dwarf.
what determines the size of a star or planet orbit?
the object’s speed
