CHAPTER 11 VOCAB Flashcards
asteroid
millions of small, rocky objects that orbit the sun in the asteroid belt between mars and jupiter
comet
made of gas, dust, and ice and moves around the sun in an oval-shaped orbit (elliptical)
astronomical unti
average distance from earth to the sun
period of revolution
the time it takes an object to travel once around the sun
period of rotation
the time it takes an object to make one complete rotation around itself
our star
the sun, it is the center of our solar system
sun
an object in space made of gases which nuclear fusion reactions occur that emit energy
orbit
an object path around the sun
planets
spherical objects that orbit around the sun and cleared their neighborhood
dwarf planet
spherical objects that orbit around the sun, but not have cleared the neighborhood and is not a satellite
terrestrial planet
planets closest to the sun, they are made up of rock and metal, and have solid outer layers
inner planets
mercury, venus, earth, and mars
outer planets
jupiter, saturn, uranus, and neptune
greenhouse effect
occurs when a planet’s atmosphere traps solar energy and causes the surface temperature to increase
gas giant
outer planets made of hydrogen and helium, they have thick gas and liquid layers covering a solid core
galilean moon
four largest moons of jupiter: io, europa, ganymede, and callisto. they are all made of rock and ice
meteoroid
small, rocky particle that moves through space
meteor
streak of light in earth’s atmosphere made by a glowing meteoroid
meteorite
meteoroid that strikes a planet or moon
impact crater
round depression formed on the surface of a planet, moon, or other space object by the impact of a meteorite
short-period comets
comets that takes less than 200 earth years to orbit the sun
long-period comets
comets that take more than 200 earth years to orbit the sun
satellite
can be natural or man-made object that is in orbit
