Meteors or ‘shooting stars’ light up our skies while meteorites even manage to flame through our atmosphere before hitting Earth.

Meteor shower calendar

Shower Name

Date of Maximum

Normal Limits

Rate/
Hour

Description

Quadrantids

Jan 3-4

Jan 1-6

60

Blue meteors with fine trains

Lyrids

April 22

April 16-25

10-15

Bright fast meteors, some with trains. Associated with Comet Thatcher

Eta Aquarids

May 5

Apr 24-May 20

35

Low in sky. Associated with Comet Halley

Capricornids

July 8-26

July-
August

5

Bright meteors

Alpha Capricornids

Aug 2

July 15-
Aug 25

5

Yellow slow fireballs

Perseids

Aug 12-13

July 23-
Aug 20

75

Many bright fast meteors with trains. Associated with Comet Swift-Tuttle (1737, 1862, 1992)

Draconids Oct 8 Oct 2-16 ~10 Associated with Comet 21/P Giacobini-Zimmer

Orionids

Oct 21-22

Oct 16-27

25

Fast with fine trains. Associated with Comet Halley

Taurids

South: Nov 4

North: Nov 11

Oct 20-
Nov 30

10

Very slow meteors

Leonids

Nov 17-18

Nov 15-20

Variable (30-300)

Fast bright meteors with fine trains. Associated with Comet Tempel-Tuttle

Geminids

Dec 14

Dec 7-16

75

Plenty of bright meteors, few trains

What are the differences between meteors, meteoroids, and meteorites?

The names are so similar, it's easy to get mixed up between meteors, meteoroids, and meteorites. Our astronomers have created this video to help you understand what those terms mean and what's the difference. We have also provided written definitions below.



What is a meteor?

What we are witnessing when we see a shooting star is a small piece of interplanetary matter, called a meteor, entering the Earth's atmosphere and 'burning up' at a height of about 100 km.

These small particles are moving very fast relative to the Earth and when they enter the Earth's atmosphere, they are completely evaporated and the air in the path of the meteor is ionized. We see light from the emission of radiation from the ionized gas and from the white-hot evaporating particle. The trail is the hot gas gradually cooling down.

What is a meteor shower?

Every meteor shower has a progenitor Comet. Comets which live a long way from the Sun sometimes tumble in towards the Sun and start to have a short periodic orbits of less than 200 years.

A good example is Halley’s Comet which orbits the Sun every 76 years and is the progenitor of the Orionids. As the Comet gets close to the Sun it heats up, and being a ball of mostly ice it starts to evaporate. Rather becoming a liquid it literally turns straight into a cloud of particles, just sublimes – a big cloud of debris.

As the comet goes around the Sun it is constantly filling its orbit with debris, and if its orbit coincides with the Earth’s orbit then every year you’ll go through that cloud of debris. Those little pieces then burn up in the Earth’s atmosphere as we smash into them and create shooting stars. Showers occur when we go through specific clouds of debris and then throughout the year we experience sporadic meteors which are just little pieces that are everywhere.

What is a meteor storm?

“Meteor storms are amazing and really apocalyptic”

ROG Astronomer Tom Kerss remembers his experience of a meteor storm

A meteor storm occurs when you go through a really unusually dense part of a comet’s debris cloud. It’s very unpredictable - you can’t really tell when it’s going to happen but when it does happen it’s possible to see thousands of meteors per hour for one or two hours.

I saw a meteor storm a number of years ago. It was extraordinary – I was seeing about 300 meteors in the space of about 20 minutes. And you could really see where the radiant was because the meteors were so regular that your eye could trace them all back to a common point where the radiant was.

What are meteorites?

When larger chunks of interplanetary matter enter the atmosphere it is unlikely that all of each one will be evaporated. The outer layers will disappear but the centre is likely to survive and will hit the ground as a meteorite. The speed with which small meteorites hit the ground can be around 500 km/h.

More than 2000 meteorites have been recovered. They are of different types, Stony meteorites, iron meteorites and the rare carbonaceous chondrites. The largest meteorite that has been found is the 60 tonne Hoba iron meteorite; the largest stony meteorite weighs about a tonne and the Allende carbonaceous chondrite was a series of chunks that totalled about 5 tonnes.

One of the best-known impact craters is the Arizona crater in the USA, which is 1280 metres across and 180 metres deep. It was formed several thousand years ago by a 250,000 tonne meteorite with a diameter of 70 metres hitting the Earth at a speed of nearly 60,000 km/h!

The oldest thing you'll ever touch

Handle a 4.5 billion year-old meteorite when you visit the Astronomy Galleries.

Meteorite at the Royal Observatory Greenwich
Visitors to the Observatory here in Greenwich can touch a 4.5 billion-year-old meteorite

The Perseids

The Perseids are one of the best-known meteor showers and can be seen in August around 12 August. The  radiant is in the constellation Perseus, just below the familiar 'W' of the constellation of Cassiopeia. At this time of year this can be seen reasonably high in the north-eastern sky at nightfall.

Find out more about the Perseid meteor shower

 

Sporadic meteors

If no prominent shower is active then most of the meteors that are seen will come from random directions in space. These meteors are called sporadic meteors and about one every ten minutes is the normal rate for them to be seen.

Most fire-balls and meteorites are sporadic meteors. The material in these meteors is associated with the material in the asteroids and it is likely that they represent material that has come from fragmented asteroids.

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