Orionid meteor shower 2020: when and how to watch
Active throughout the month, the Orionid meteor shower is due to peak in the early hours of 22 October. The Draconids also make an appearance earlier in the month.
Planetary science researcher and meteorite expert Dr Ashley King shares his tips on how to catch the best view. Plus, find out what causes meteor showers and others to look out for.
Meteors are often called shooting stars, though the bright streaks you see in the sky don't have anything to do with stars.
In fact, what you're wishing on are tiny particles of dust - leftovers from the birth of our solar system - vaporising in Earth's atmosphere.
Tips for watching the Orionids
Some of the more spectacular of these meteors can sometimes be visible from central London however you're bound to get the best experience away from the light pollution of the city.
'The darker the skies, the better your odds are of seeing the really faint ones as well,' says Ashley. 'You could go to the coast or stand on a hill in the middle of the countryside somewhere.'
You also need to be patient.
'You might not be able to see anything for the first 10 minutes while your eyes adjust,' he adds.
'Once you get used to the low light levels you'll begin to notice more and more. So don't give up too quickly.'
If you can't escape the lights of the city, or the weather is against you on the night, watch the meteor shower live online with the UK Meteor Network.
What causes a meteor shower?
Meteor showers occur when Earth passes through a stream of tiny pieces of debris (meteoroids) left behind by a comet.
Most comets are composed of dust and ice, which Ashley likens to 'a big, dirty snowball.'
'As comets orbit the Sun, the ice sublimes [changes from a solid to a gas] and the trapped dust is swept out into a tail behind them.'
Nearly all meteors are tiny dust particles, about the size of a grain of sand travelling at tens of kilometres per second through space.
'As they come out of the vacuum of space and into Earth's atmosphere, that little dust grain interacts with all the particles and ions in the atmosphere. It gets heated up by the friction and forms the impressive flash that we see,' he says.
'The Earth isn't close to the comet - it's just passing through some of the dust it left behind.'
At other times of year, you may still see meteors in the sky, but only about one every 10 minutes. These sporadic meteors, as they are known, will come from random directions.
Orionid meteor shower
The Orionid meteor shower takes place annually and is due to reach a peak on the morning of 22 October as Earth passes through the trail of Halley's Comet, one of the most famous comets of all time.
Orionids are some of the fastest and brightest meteors, entering the atmosphere at just under 70 kilometres per second.
Orionids get their name because they seem to radiate from the constellation Orion, but they can appear anywhere in the sky.
If the sky is clear, stargazers could expect to see 25 meteors per hour. However, you will have more luck spotting them once the quarter Moon sets in the early evening.
Halley's Comet is a short-period comet, meaning it takes less than 200 years to go around the Sun. Its orbital period is 75-76 years and it last passed close to Earth in 1986. It will be back again in 2061.
In 1986 space agencies sent missions (Vega, Giotto, Sakigake and Suisei) to Halley (the 'Halley Armada'), so it's one of the best studied comets.
Halley's Comet has been observed for centuries - in 1066 it was considered an omen of doom. It even appears on the Bayeux Tapestry, which depicts events leading up to the Norman conquest of England in the eleventh century.
Top meteor showers to look out for in 2020
- The Quadrantids, due to peak on 3-4 January with around 60 meteors per hour, possibly from the trail of the asteroid 2003 EH1 or perhaps from a comet
- The Lyrids, due to peak on 21-22 April with nearly 20 meteors per hour from the trail of the comet Thatcher
- The Eta Aquariids, due to peak on 5-6 May with 10-40 meteors per hour from the trail of the comet 1P/Halley
- The Delta Aquariids, due to peak on 29-30 July with 20 meteors per hour, possibly from the trail of comet 96P/Machholz
- The Perseids, due to peak on 12-13 August with around 80 meteors per hour from the trail of the comet 109P/Swift-Tuttle
- The Draconids, due to peak on 8 October with only about 10 meteors per hour from the trail of comet 21P/Giacobini-Zinner
- The Orionids, due to peak on 21-22 October with 25 meteors per hour from the trail of the comet 1P/Halley
- The Taurids, due to peak on 10-11 November with 10 meteors per hour from the trails of Asteroid 2004 TG10 and Comet 2P/Encke
- The Leonids, due to peak on 17-18 November with 15 meteors per hour from the trail of the comet 55P/Tempel-Tuttle
- The Geminids, due to peak on 14-15 December with more than 100 meteors per hour from the trail of the asteroid 3200 Phaethon (although it is officially classified as an asteroid, it produces a tail like a comet)
- The Ursids, due to peak on 21-22 December with under 10 meteors per hour from the trail of the comet 8P/Tuttle
Leonid meteor shower
The Leonid meteor shower takes place annually and is due to reach a peak on the night of 17 November as Earth crosses the trail of comet 55P/Tempel-Tuttle.
Entering the atmosphere at 70 kilometres per second, the Leonids have some of the fastest-moving and brightest meteors. Stargazers can expect to see 10 to 20 meteors per hour at the shower's peak. Moonlight won't be an issue this year as the Moon will set in the early evening.
Leonids get their name because they seem to radiate from the constellation Leo.
Comet Tempel-Tuttle is a short-period comet, taking 33 years to go around the Sun. Its last visit was in 1998 with a return expected in 2031. The comet is quite small, only two miles across.
The comet is named for the two astronomers, Ernst Tempel and Horace Tuttle, who each independently discovered it in 1865 and 1866 respectively.
Geminid meteor shower
One of the most spectacular meteor showers of the year, the Geminids take place annually as the Earth in its orbit passes through the trail of dust left by the 'rock comet' 3200 Phaethon.
At the shower's peak on the night of 14 December, stargazers willing to brave the cold could be rewarded with a display of more than 100 multicoloured meteors per hour.
It is set to be the best shower of the year for viewers in the northern hemisphere, as it is one of the most active and its peak coincides with a new Moon.
Geminids get their name because meteors appear to radiate from the constellation Gemini.
Discovered by satellite in 1983, Phaethon is the only asteroid that is associated with a meteor shower. It has an orbital period of 524 days and travels even closer to the Sun than Mercury does.
According to Ashley, there is quite a lot of debate about what Phaethon really is.
'Like other comets, Phaethon has an elliptical orbit but is unusual as it doesn't go to the outer solar system. It has been officially classified as a B-type asteroid, but it has also been suggested that it could be a "rock comet" or a "dead comet".'
Phaethon is considered a potentially hazardous asteroid, meaning it could impact the Earth at some point hundreds of years in the future. For this reason it is very well studied and there are plans to possibly send space missions there in the future.
Phaethon is the same type of asteroid as Bennu, which is currently being visited by the NASA mission OSIRIS-Rex.
Lyrid meteor shower
The Lyrid meteor shower takes place annually between 16-25 April as the Earth in orbit passes through the dust trail left behind (hundreds of years ago) by comet C/186 G1 (Thatcher).
The most spectacular are 'Lyrid fireballs', which occur when meteoroids the size of a large marble pass through the atmosphere. Their slightly larger size produces a meteor train which we see as a flash and line across the night sky.
The Lyrids meteor shower gets its name because it appears to radiate from the area of the sky near the constellation Lyra, the Harp - but the meteors can appear anywhere in the sky.
Comet Thatcher, responsible for the Lyrids meteor shower, takes 415 years to complete a full orbit of the Sun.
We have no photographs because the last time it visited the inner solar system was in 1861 - well before the widespread use of photography.
Perseid meteor shower
One of the best meteor showers of the year to watch, the Perseid meteor shower is due to reach a peak between the 12 and 13 August as Earth passes through the trail left behind by the very large comet Swift-Tuttle.
The shower this year is expected to feature around 80 meteors per hour at its peak, including bright streaks and fireballs. Although a quarter Moon will obscure fainter meteors, stargazers can still expect a good show.
Most meteors are pieces of dust around the size of a grain of sand. Larger pieces can create spectacular fireballs and make bright trails across the sky.
Perseids get their name because they appear to radiate from the constellation Perseus, but they can appear anywhere in the sky. Best viewing is from a dark location, after midnight and before sunrise on 13 August.
Swift-Tuttle, responsible for the Perseids meteor shower, takes 133 years to complete a full orbit of the Sun.
At 26 kilometres wide it is the largest solar system object to regularly pass so close to Earth.
Swift-Tuttle's elongated orbit means that debris enters the Earth's atmosphere at great speed.