A meteoroid is a piece of rock, smaller than an asteroid and larger than a speck of dust, moving through space. A meteoroid becomes a meteor when it enters Earth’s atmosphere. A meteor becomes a meteorite when it hits the ground (which rarely happens, since most burn up in the atmosphere).
Examples
Many of the dangers of space travel exist in a very scary way, from radiation poisoning and meteoroid crashes, to starvation and mental health. [Primary Ignition]
A Somerville photographer captured a photo of what he believes was a meteor streaking across the sky over Harvard Square Saturday night. [WCVB-TV]
A ground-trembling incident has left residents in a market town asking whether a meteorite had landed nearby. [Cambridge News]
Meteoric
The adjective meteoric can mean of, relating to, or formed by a meteoroid—for example:
The meteoric origin of the event is supported by eyewitness accounts of a bluish light moving across the sky from east to north. [Salem News]
But meteoric is more often used in its metaphorical sense—like a meteor in brilliance, speed, or transience. It often appears in the phrase meteoric rise, which is a little illogical because meteors never rise. But writers have been using meteoric as a synonym of quick or short-lived for a long time, and this usage is widespread.
It’s more logical to use meteoric in reference to something that appears suddenly, has a moment of intensity, and quickly burns up or comes to a natural end. For example, these writers use meteoric well:
In fact it turns out that’s why Activision decided to throw you under the bus after a brief albeit meteoric five-year run. [PC World]
Egypt is not the only country experiencing the after-effects of Tunisia’s meteoric uprising. [North Wind Online]