"Characteristics of..."
large object that orbits a star, enough mass for gravity to create a round shape, pulls all other smaller objects into its gravity
a planet!
everything revolves around the sun!
heliocentric model/theory!
space rock mostly made of iron, can be huge or tiny
meteoroid
a huge group of stars held together by gravity
a galaxy!
why did people accept the geocentric model (at first)?
objects seemed to move across the sky, and people did not believe Earth was moving!
natural objects that orbit a planet, smaller than a planet
moon
everything revolves around the Earth!
geocentric model/theory
"shooting star"; can be seen form Earth's atmosphere because it streaks across the sky in a brief flash of light
meteor
what are the three types of galaxies?
BONUS: describe each! (at least one thing about each)
spiral: center disc with arms reaching out around (pinwheel); shine brightly with many young stars
elliptical: long oval shape; many older stars and do not shine brightly, most abundant type
irregular: no shape, formed likely when galaxies collide; new and old stars
What is so important about radio waves?
Radio waves were evidence of the universe moving, which supported the big bang theory and disproved the steady state theory!
space rocks that are mostly made of iron; they can be as small as a grain of dust, or the size of a small asteroid.
everything started with a big explosion and then the universe kept expanding!
the big bang theory
when a space rock lands on Earth
meteorite
What do scientists believe is at the center of the Milky Way galaxy?
a. another planet
b. a black hole
c. Andromeda
b. a black hole!
What is the Big Crunch?
the part of the Cyclic Model theory that states after the Big Bang reaches its expansion limit, everything will contract back to a single point (snapping back like a rubberband), thus starting over again!
"born" from clouds of gas and dust, made up of very hot gases, gravity pulls gas and dust together
a star!
the big bang theory didn't begin everything! big bang --> big crunch --> big bang --> big crunch
cyclic model/theory
what makes asteroids and comets similar? What makes them different?
Both orbit the sun.
Comets are made of: ice, frozen gases, rock
Asteroid: big space rock
What is a nebula?
a cloud of dust and gas from which a star is "born"!
What is a red shift?
BONUS: What is a purple shift?
Evidence that a start is moving away!
Purple: means a star is approaching!
formed by spinning clouds of gas, there are three types, individual stars are born within these
a galaxy!
the universe has the same amount of mass
steady state theory
Which two planets DO NOT have moons?
What is the observable universe?
objects in space that can be observed and detected!
What is still uncertain about the universe?
a. How stars were formed
b. What the future of the universe is
c. If we will get another planet
b. What the future of the universe is!
We still don't know for sure what will happen!