Topic

#The physics of meteors

Gravity, orbits, entry, heating and energy: the physics that brings a meteorite to the ground.

A meteoroid's journey is a lesson in physics. Gravity and Newton's laws set its orbit around the Sun, and the pull of Jupiter can slowly reshape that orbit until it crosses Earth's path.

It meets our atmosphere at between about 11 and 72 kilometres per second. The air in front of it is squeezed and heated, so the surface melts and streams away. That process, called ablation, makes the glowing meteor and leaves a thin fusion crust on any piece that survives.

Most of the speed is lost high in the air. The surviving fragments then fall at only a few hundred kilometres per hour, a stage called dark flight. A large meteoroid can break apart violently and release its energy as an airburst, as happened over Chelyabinsk in 2013, when the shock wave broke windows across the city.

Part of Meteorites across the sciences.

Lessons (5)

Asteroids: the parent bodiesMeteorites are samples of asteroids, and asteroids are leftovers from the building of the planets.
Fireball networks: from sky to orbitWhen a fireball is filmed from several places at once, scientists can find where its meteorites landed and trace where they came from in spa
The journey through the atmosphereEvery meteorite survived one of the most violent journeys in nature. Here we follow a meteoroid from the edge of space to the ground, step b
Delivery: from asteroid families to EarthWhich asteroids are our meteorites actually coming from? Dynamics, spectroscopy and exposure ages are converging on answers.
When a meteorite fallsWhat really happens when a space rock falls to the ground? The answer might surprise you.

Courses (21)

Atmospheric entry and fragmentationA meteoroid is decelerated, heated and often shattered by the air. Simple models of drag and ram pressure explain where it breaks up and how
The energy of impacts and airburstsImpact energies range from a firecracker to the end of the dinosaurs. This lesson quantifies them, compares airbursts with cratering impacts
Gravitational fields and escapeHow does a rock leave Mars, the Moon or the asteroid Vesta? Newton's law of gravitation and the idea of gravitational potential give the
Orbits, Kepler's laws and resonancesKepler's third law connects an asteroid's distance from the Sun to its orbital period.
A-level: The physics and chemistry of meteoritesTwelve lessons that apply A-level physics, chemistry and geology to meteorites: gravitational fields and Kepler's laws, impact and entry
Fireballs, camera networks and recoveryModern camera networks can turn a few seconds of light into a meteorite in a museum within days. This lesson explains how, and how members o
The journey from the asteroid beltMost meteorites begin as fragments of asteroids between Mars and Jupiter. This lesson follows the long, slow route that brings a few of them
Forces and orbitsAsteroids, planets and meteoroids all move under gravity. This lesson applies Newton's laws and circular motion to orbits, and explains
Heating and melting: the fusion crustDuring entry the surface of a meteoroid is heated to melting in seconds. Specific heat capacity and specific latent heat explain why the cru
How the Solar System formedThe Sun and planets formed from a cloud of gas and dust about 4.6 billion years ago.
The kinetic energy of space rocksBecause they move so fast, even small meteoroids carry huge amounts of energy. This lesson uses the kinetic energy equation to explain fireb
GCSE: Meteorites across the sciencesTwelve lessons that use meteorites to practise GCSE physics, chemistry and biology: the formation of the Solar System, isotopes and half-lif
Our Solar System and where space rocks liveThe Sun, eight planets, their moons and millions of smaller bodies make up our Solar System.
Rocks from the Moon and MarsA few meteorites have come from the Moon and from Mars. In this lesson you will find out how a rock can escape a world and how scientists kn
The fiery fall through the airA meteoroid hits the air at tremendous speed. In this lesson you will find out why it glows, why its outside melts and how it slows down bef
Your certificateComplete all 12 lessons of the free Key Stage 3: Meteorites and the Solar System course to print a certificate of completion.
Drag, terminal velocity and dark flightAfter the bright fireball ends, a meteorite still has kilometres to fall. This lesson uses balanced and unbalanced forces to explain how fas
Gravity, weight and orbitsGravity holds the Solar System together and decides where meteorites end up. In this lesson you will calculate weight on different worlds an
Light, sound and meteor showersMeteors are seen instantly but heard minutes later, and some return on the same dates every year. This lesson uses waves and Earth's orb
Speed and energy on entryA meteoroid arrives with enormous speed and kinetic energy. In this lesson you will calculate entry speeds and trace where all that energy g
Key Stage 3: Meteorites and the Solar SystemTwelve lessons for Years 7 to 9 that use meteorites to teach space physics, forces, density, energy, the rock cycle, elements and compounds,

Space missions (2)

LucyA twelve-year tour of the Trojan asteroids, possible fossils of planet formation. The Trojan asteroids travel around the Sun in two great sw
New HorizonsThe first visit to Pluto, and to Arrokoth, a pristine building block of the planets.

Glossary (12)

Questions and answers (15)

Did Jupiter affect which meteorites reach Earth?Yes. Jupiter's gravity shaped the asteroid belt, scattered outer Solar System material inwards, and today steers asteroid fragments onto
How can a rock from Mars reach Earth?A large asteroid impact on Mars can blast surface rocks fast enough to escape the planet's gravity, about 5 kilometres per second.
How can I explain why meteors glow without saying friction?Meteors glow mainly because they compress the air in front of them so violently that it heats up, not because of rubbing friction.
How can I teach kinetic energy using impacts?Use the equation half m v squared with real meteoroid speeds to show why small space rocks carry enormous energy and why speed matters more
How can I teach orbits and gravity using asteroids?Asteroids show how gravity shapes paths around the Sun, how resonances with Jupiter deliver meteorites, and how gravity assists and deflecti
How fast do meteorites travel?Meteoroids hit the top of the atmosphere at between about 11 and 72 km/s. Air resistance then slows survivors to a free fall of typically a
What is dark flight?Dark flight is the final stage of a meteorite's fall, after it has slowed so much that it stops glowing.
What is the difference between an asteroid and a planet?Planets are big, round and have cleared their paths around the Sun. Asteroids are much smaller, usually lumpy, and share their paths with ma
What sounds does a falling meteorite make?Big fireballs can produce delayed sonic booms and rumbles like thunder, and falling stones may whistle or buzz in their final moments.
What would I see if I stood on an asteroid?You would see a rocky, dusty, cratered ground under a black sky, with the Sun shining brightly. Gravity would be so weak you could jump into
Where do meteorites come from?Most meteorites are fragments of asteroids, chipped off in collisions in the asteroid belt between Mars and Jupiter.
Which planet gets hit by the most space rocks?Jupiter. Its enormous size and strong gravity pull in more comets and asteroids than any other planet.
Why are there no known meteorites from Mercury or Venus?Rocks blasted off Venus are blocked by its thick atmosphere and strong gravity, and rocks from Mercury tend to fall towards the Sun, so few,
Why aren't asteroids round?Most asteroids are too small for their gravity to pull them into a ball, so they stay lumpy, like potatoes or peanuts.
Why do most meteoroids burn up in the atmosphere?Most meteoroids are tiny, and they hit the air so fast that it is compressed and heated in front of them, melting and vaporising their surfa

Meteor showers (1)

The Southern Taurids meteor showerSouthern Taurids meteor shower: peak broad maximum from about 10 October to early November (often quoted around 5 November), active about 10

People (2)

Daniel KirkwoodThe astronomer who discovered in 1866 the gaps in the asteroid belt made by Jupiter's gravity, now called the Kirkwood gaps.
Hubert Anson NewtonThe Yale mathematician who traced the Leonid meteor storms back a thousand years and predicted their return in 1866.