Chapter 21 Flashcards
What is the solar system
the sun and the group of objects that move around it
what does planet literally mean
wanderers
where are most things that humans on earth can see in the night sky
outside our solar system
what is the closet star to earth named
the Sun
what is the largest object in our solar system
the Sun
how many times larger is the sun than the largest planet in our solar system
10 times larger
what is the sun mostly made up of
hydrogen
what does the sun use to create energy
nuclear fusion
what does the sun provide
light and a gravational pull to keep the planets in orbit around it
what qualities does a planet have to have to be considered a planet
must orbit the sun and have a nearly spherical shape
how many planets do we have
8
what are the inner planets (4 closest planets to the sun) and what are they mostly made of.
Mercury, Venus, Earth, Mars. Mostly made of solid rock
what are the outer planets (4 farthest planets from the sun)
Jupiter, Saturn, Uranus, Neptune
what are the outer planets made of
they are gas giants
what is a dwarf planet
a spherical object that orbits the sun, but dosent have a greater mass than objects nearby it.
what are dwarf planets made of
rock and ice and these planets are very small
what are the names of some dwarf planets
Ceres, Eris, Pluto, Makemake
what are astroids
small, rocky, non-spherical objects that orbit the sun in a belt between mars and jupiter
what sizes are astroids
range in sizes from a meter to hundreds of meters
what are comets made of
gas, dust and ice
what shape are comets orbits
long ovals
where do comets come from
outer parts of the solar system
what is an astronomical unit
is the average distance from earth to the sun (like the Will measurement that we did in class)
what is the distance from earth to the sun
~150 km