Stars and planets Flashcards
What is a star?
A star is a massive, luminous ball of plasma held together by gravity, undergoing nuclear fusion.
True or False: The Sun is the only star in our galaxy.
False
Fill in the blank: The process by which stars generate energy is called __________.
nuclear fusion
What is the closest star to Earth?
Proxima Centauri
What is a planet?
A planet is a celestial body that orbits a star, is spherical in shape, and has cleared its orbit of other debris.
Multiple Choice: Which of the following is NOT a planet in our solar system? A) Mars B) Venus C) Pluto D) The Moon
D) The Moon
What are the four terrestrial planets in our solar system?
Mercury, Venus, Earth, and Mars
True or False: Gas giants are primarily composed of rocky materials.
False
What is the main difference between a planet and a dwarf planet?
A dwarf planet has not cleared its orbit of other debris, while a planet has.
Fill in the blank: The largest planet in our solar system is __________.
Jupiter
What is the term for the path a planet takes around a star?
orbit
Multiple Choice: Which of the following is a characteristic of gas giants? A) Solid surface B) Thick atmosphere C) Small size D) Short orbital periods
B) Thick atmosphere
What is the main component of a star’s core?
Hydrogen
True or False: All stars are born in nebulae.
True
What is a supernova?
A supernova is a powerful explosion that occurs at the end of a star’s life cycle, often creating a neutron star or black hole.
Fill in the blank: The __________ is the region of space around a star where planets can form.
protoplanetary disk
What is the main source of energy for the Sun?
Nuclear fusion of hydrogen into helium
Multiple Choice: Which of the following is classified as a terrestrial planet? A) Saturn B) Earth C) Neptune D) Jupiter
B) Earth
What is the term for a group of stars that form a recognizable pattern?
constellation
True or False: The Milky Way is the only galaxy in the universe.
False
What is the process called when a star exhausts its nuclear fuel and collapses?
stellar evolution
Fill in the blank: The __________ is the region around a black hole from which nothing can escape.
event horizon
What is the significance of the Hertzsprung-Russell diagram?
It classifies stars based on their luminosity and temperature.
What is the primary factor that determines a star’s life cycle?
Its mass
Multiple Choice: Which of the following is NOT a type of galaxy? A) Spiral B) Elliptical C) Irregular D) Circular
D) Circular
