Earth's Place in the Universe Flashcards
(15 cards)
What is nuclear fusion?
The process where hydrogen atoms combine to form helium, releasing energy (this powers stars).
What does a star’s color indicate?
Its surface temperature (blue is hottest, red is coolest).
What are the main life cycle stages of a low-mass star?
Nebula -> Protostar -> Main sequence -> Red giant -> White dwarf
What happens to a massive star after a supernova?
It becomes either a neutron star or black hole.
What is the Milky Way?
A barred spiral galaxy containing our solar system.
What evidence supports the Big Bang theory?
Redshift of galaxies and cosmic microwave background radiation?
What causes day and night?
Earth’s rotation on its axis.
What causes seasons?
Earth’s 23.5 degree axial tilt and its revolution around the Sun.
What causes the phases of the Moon?
The portion of the Moon lit by the Sun, as seen from Earth.
What is a lunar eclipse?
Earth blocks sunlight from reaching the Moon.
What causes tides on Earth?
The gravitational pull of the Moon and the Sun.
What are spring tides?
Highest high tides during new/full moons due to Sun and Moon alignment.
What are neap tides?
Lower tides when the Sun and Moon are at right angles (first/third quarter).
What is a solar eclipse?
The Moon blocks sunlight from reaching Earth.
What are asteroids and comets?
Asteroids=rocky bodies; comets=ice bodies with tails when near the Sun.
