Three names for one object
The words change with location, not with the object. NASA's fact page on meteors puts it in three steps. A meteoroid is a space rock that ranges in size from dust grains to small asteroids, and the name only applies while the rock is still in space. When a meteoroid enters the atmosphere of Earth, or of another planet, at high speed and burns up, it is called a meteor. When a meteoroid survives the trip through the atmosphere and hits the ground, it is called a meteorite.
So a meteor is an event you watch and a meteorite is a thing you hold. The American Meteor Society (AMS) draws the same line in its meteor FAQ: a meteor is the streak of light produced when a meteoroid enters the atmosphere, and a meteorite is material that survives that passage and reaches the ground. "Shooting star" is just a popular name for a meteor. No star is involved.
Two more words sit in between. The AMS fireball FAQ calls a very bright meteor, generally brighter than magnitude -4, a fireball; that is about as bright as Venus in the morning or evening sky. A bolide is a special type of fireball that explodes in a bright terminal flash at its end, often with visible fragmentation. The table below lines up all five terms.
| Name | Where the object is | What you actually see or hold | Typical size given by the source |
|---|---|---|---|
| Meteoroid | Still in space | Nothing; it is too small and dark to see | Dust grain up to a small asteroid (NASA) |
| Meteor | Passing through the atmosphere | A streak of light, the "shooting star" | Sand grain to small pebble for many visible meteors (AMS) |
| Fireball | Passing through the atmosphere | A meteor brighter than about magnitude -4, roughly Venus | Larger than an ordinary meteor; AMS gives no fixed size |
| Bolide | Passing through the atmosphere | A fireball that ends in a bright terminal flash, often breaking apart | No fixed size given |
| Meteorite | On the ground | A rock you can pick up, often with a fusion crust | Typically pebble to fist (NASA) |
The size column mixes two sources on purpose. NASA's range for meteoroids runs from dust to small asteroids because it covers everything in space. The AMS range describes the particles behind many visible meteors, which is why it is so much smaller. Neither source sets a size cutoff between a meteoroid and an asteroid, so this page does not either.
What happens during the few seconds of a meteor
Speed is what turns a small particle into a bright streak. The AMS gives typical entry speeds of about 11 to 72 kilometers per second, or 25,000 to 160,000 miles per hour. At those speeds, it says, even a small particle releases a lot of energy as it interacts with the air, so a particle does not need to be large to make a noticeable streak.
Most of that light appears high up. The AMS puts most visible meteor activity at roughly 80 to 120 km (50 to 75 miles) above the ground. That is a general range: very fast meteors can light up higher, and some slower, brighter ones get deeper. For comparison, the AMS points out that meteors burn up far higher than the highest clouds, so a streak seen below a cloud deck was not a meteor.
A bright meteor can leave something behind in the sky for a short time. The AMS describes two kinds of trail. A train is a glowing trail of ionized and excited air, usually above 80 km, that most often lasts a few seconds and very rarely several minutes. A smoke trail, usually below 80 km, is a non-glowing trail of dust stripped off the object, and it is seen more often after daylight fireballs.
The meteor itself is brief. The AMS says a fireball usually lasts only a few seconds, and it uses that as a test: if you had time to grab your phone and take a picture, what you saw was almost certainly an aircraft contrail, which stays in the sky for minutes or hours.
Why most meteors never become meteorites
The short answer is that most of the material is destroyed on the way down. NASA estimates that about 48.5 tons (44,000 kilograms) of meteoritic material falls on Earth each day, and its meteors overview adds that almost all of it is vaporized in the atmosphere. Larger objects fare little better. NASA's fact page says most space rocks smaller than a football field break apart in the atmosphere, and less than 5% of the original object usually makes it to the ground.
Meteor showers are the clearest case. NASA says showers come from the dusty trails left by comets, and in a few cases asteroids, and that most of this comet debris is between the size of a grain of sand and a pea. It burns up before reaching the ground. NASA's advice is direct: do not expect to find meteorites after a meteor shower, because comet material is fragile. It adds that the Taurids and Geminids could in theory drop meteorites now and then, but no remnants have been traced to them definitively.
The AMS makes the same point from the observer's side. In its meteor FAQ it says the particles behind meteor showers typically disintegrate high in the atmosphere, which is why it calls watching a shower safe, and that most shower particles do not survive to the ground.
Put together, the odds run one way. A single clear night can show several meteors per hour even without a shower, according to NASA, and the AMS estimates that several thousand fireball-magnitude meteors happen in the atmosphere every day, mostly over oceans and empty land or hidden by daylight. Both sources point the same way: most of the particles behind those streaks burn up and never reach the ground.
What a meteorite is, once it lands
A meteorite on the ground can look a lot like an ordinary rock. NASA notes that meteorites usually have a burned exterior that can look shiny, called a fusion crust, which forms when the outer surface melts during the fall. NASA gives a typical size range of a pebble to a fist.
NASA sorts meteorites into three major types: irons, stonys, and stony-irons. The split between them depends on whether you count falls or finds, as the next table shows.
| Type | What it is made of | Share of falls vs finds (NASA wording) |
|---|---|---|
| Stony | Mostly rock | The majority of meteorites that fall to Earth |
| Iron | Mostly metal | Most of the meteorites discovered long after they fell |
| Stony-iron | A mix of rock and metal | NASA lists it as the third major type without a share |
The reason for that flip is practical. NASA says irons are heavier and easier to tell apart from Earth rocks than stony meteorites are, so they are the ones people tend to recognize long after a fall. Because most meteorites are hard to tell from Earth rocks, NASA points to a few places where they are much easier to identify: deserts and the ice of Antarctica, where a dark stone stands out.
Most meteorites come from asteroids. NASA counts more than 50,000 meteorites found on Earth and says 99.8% of them come from asteroids. The remaining 0.2% is split roughly equally between meteorites from Mars and from the Moon; NASA lists over 60 known Martian meteorites and nearly 80 lunar ones. Those counts grow as new finds are classified, so treat them as the figures on NASA's page at the time of writing. Some meteorites date back up to 4.6 billion years, which is why NASA describes them as samples of the original materials that formed the planets.
A quick way to keep the words straight
Think of the suffixes. Meteor-oid is the object out in space. Meteor is the light show in the air. Meteor-ite is the rock on the ground.
Then ask where the thing is right now. If it is in space, use meteoroid. If it is glowing across the sky, use meteor, or fireball if it outshines Venus. If someone is holding it, it is a meteorite, and the right follow-up question is which of NASA's three types it belongs to.
The same naming holds on other worlds. NASA's definition of a meteor covers any planet with an atmosphere, and its fact page shows an iron meteorite named Lebanon that NASA's Curiosity rover encountered on Mars. Our Ganymede vs the Moon guide puts two moons side by side with NASA and JPL figures.