The Eta Aquariid Meteor Shower.

The Eta Aquariid Meteor Shower will peak before dawn on Wednesday 6 May 2026, with up to 45 meteors per hour at it's peak, radiating from the constellation of Aquarius. The radiant point of this shower does not spend long above the horizon in the Northern Hemisphere at this time of year, but is often a good display in the Southern Hemisphere between midnight and dawn. The Eta Aquarids are potentially visible between 19 April and 28 May, but are extremely hard to spot away from the peak of activity. With the last Quarter Moon in Sagittarius, pre-dawn viewing may suffer from some light interference. 

The radiant point (point from which the meteors appear to radiate) of the Eta Aquariid Meteors. Universe Today.

Meteor showers are thought to be largely composed of material from the tails of comets. Comets are composed largely of ice (mostly water and carbon dioxide), and when they fall into the inner Solar System the outer layers of this boil away, forming a visible tail (which always points away from the Sun, not in the direction the comet is coming from, as our Earth-bound experience would lead us to expect). Particles of rock and dust from within the comet are freed by this melting (strictly sublimation) of the comet into the tail and continue to orbit in the same path as the comet, falling behind over time.

The Earth passing through a stream of comet dust, resulting in a meteor shower. Not to scale. Astro Bob.

The Eta Aquarid Meteor  Shower is caused by the Earth passing through the trail of Halley's Comet, where it encounters thousands of tiny dust particles shed from the comet as its icy surface is melted (strictly sublimated) by the heat of the Sun. Halley's Comet only visits the inner Solar System every 75 years (most recently in 1986 and next in 2061), but the trail of particles shed by it forms a constant flow, which the Earth crosses twice each year; in May when it causes the Eta Aquarid Meteor Shower and in October when it causes the Orionid Meteor Shower.

Halley's Comet imaged on 8 March 1986 from Easter Island. William Liller/International Halley Watch Large Scale Phenomena Network/NASA/Wikimedia Commons.

Halley's Comet has been observed repeatedly and recognised as the same recurring object since at least 240 BC. However, it takes its modern name from the eighteenth century English Astronomer Edmund Halley, who determined the comet's periodicity in 1705.

Halley's Comet completes one orbit every 75.32 years (27 509 days) on an eccentric, orbit tilted at 162° to the plane of the Solar System (i.e. a retrograde orbit, at an angle of18° to the plane of the Solar System, but travelling in the opposite direction to the majority of the objects in the Solar System), that takes it from 0.56 AU from the Sun (59% of the average distance at which the Earth orbits the Sun, and inside the orbit of the planet Venus) to 35.1 AU from the Sun (35.1 times as far from the Sun as the Earth, and outside the orbit of the planet Neptune). As a comet with a period of more than 20 years but less than 200 years, Halley's Comet is considered to be a Periodic Comet, and a Halley-type Commet.

The orbit of Halley's Comet. Nagual Design/Wikimedia Commons.

Halley's Comet was visited by the European Space Agency's Giotto Probe in and Russian Vega 1 and Vega 2 probes March 1986, which were able to determine that the nucleus of the comet was only 15 km across, although it was surrounded by a coma about 100 000 km in diameter, made up of fragments of dust and ice released from the surface as it was heated by the Sun, causing the ices on its surface to sublimate (turn directly from solids to gasses), and that this material comprised 80% water, 10% carbon monoxide, 2.5% methane and ammonia, as well as trace amounts of more complex hydrocarbons, iron and sodium.

Halley's Comet imaged by the Giotto Probe on 14 March 1986. European Space Agency/Wikimedia Commons.

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The Leonid Meteor Shower.

Each year between 6 and 30 November (approximately) the the Earth encounters the Leonid Meteors, with peak activity this year expected before dawn on Monday 17 November. Unlike most such showers, which are essentially composed of dust particles, the Leonids comprise particles of up to 8 mm across and up to 85 g in mass, leading to some spectacular fireballs, and each year the shower is thought to deposit 12-13 tonnes of material on the Earth. The Leonid Meteor Shower is so called because the meteors they appear to originate in the constellation of Leo. (Note a meteor is a 'shooting star', a piece of material visibly burning up in the atmosphere and detectable via the light it produces when doing this; a meteorite is a piece of rock that has fallen from the sky and which a geologist can physically hold; and an asteroid is a chunk of rock in orbit about the Sun, to small to be regarded as a planet.

The radiant point of the Leonid Meteor Shower. EarthSky.

The Leonid Meteors are thought to originate from the tail of Comet 55P/Tempel-Tuttle, which orbits the Sun every 33 years, on an orbit that brings it slightly within the orbit of the Earth then out to slightly beyond the orbit of Uranus. Comets are composed largely of ice (mostly water and carbon dioxide), and when they fall into the inner Solar System the outer layers of this boil away, forming a visible tail (which always points away from the Sun, not in the direction the comet is coming from, as our Earth-bound experience would lead us to expect). Particles of rock and dust from within the comet are freed by this melting (strictly sublimation) of the comet into the tail and continue to orbit in the same path as the comet, falling behind over time. 

The orbit of Comet 55P/Tempel-Tuttle, and its position on 17 November 2025. JPL Small Body Database.

The material in the meteor shower is densest close behind the comet, and, since Comet 55P/Tempel-Tuttle has a 33 year orbit, the Leonid Meteor Shower has a 33-year cycle, with a particularly spectacular display every thirty-third year, then a gradual decline in meteor number till the end of the cycle. The last such peak year was in 1998.

Image of Comet 55P/Tempel-Tuttle taken on 31 January 1998, 60 second exposure. Martin Mobberley.

Comet 55P/Tempel-Tuttle was discovered in December 1865 by German astronomer Wilhelm Tempel, and independently in January 1866 by the American Horace Parnell Tuttle. The designation 55/P implies that it is a Periodic Comet (comet with an orbital period of less than 200 years), and that it was the 55th such body discovered. As a Comet with a Period of less than 200 years and more than 20 years it is also regarded as a Halley-type Comet.

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The Orionid Meteor Shower

The Orionid Meteors are a prolific meteor shower appearing between 2 October and 7 November each year and peaking on the nights of 20-22 October, when the shower can produce 50-70 meteors per hour, originating in the constellation of Orion (above and to the right of Orion's right shoulder). This makes them both one of the more prolific meteor showers, and one of the easiest for an amateur enthusiast to locate the radiant of (apparent point of origin). The peak of this year's display should fall just before dawn on Tuesday 21 October, coinciding with the New Moon, which should make for good viewing. The Orionids can be seen from anywhere on Earth, although viewing will be better from the Northern Hemisphere.

The radiant point of the Orionid Meteor Shower. EarthSky.

Meteor streams are thought to come from dust shed by comets as they come close to the Sun and their icy surfaces begin to evaporate away. Although the dust is separated from the comet, it continues to orbit the Sun on roughly the same orbital path, creating a visible meteor shower when the Earth crosses that path, and flecks of dust burn in the upper atmosphere, due to friction with the atmosphere.

The Earth passing through a stream of comet dust, resulting in a meteor shower. Not to scale. Astro Bob.

The Orionid Meteor Shower is caused by the Earth passing through the trail of Halley's Comet (technically Comet P1/Halley), and encountering dust from the tail of this comet. The dust particles strike the atmosphere at speeds of over 200 000 km per hour, burning up in the upper atmosphere and producing a light show in the process. The Earth does not need to pass close to Halley's Comet for the meteor shower to occur, it simply passes through a trail of dust from the comet's tail that is following the same orbital path. Halley's Comet only visits the Inner Solar System once every 75 years, last doing so in 1986. 

How the passage of the Earth through a meteor shower creates a radiant point from which they can be observed. In The Sky.

Halley's Comet has been observed repeatedly and recognised as the same recurring object since at least 240 BC. However, it takes its modern name from the eighteenth century English Astronomer Edmund Halley, who determined the comet's periodicity in 1705.

Halley's Comet completes one orbit every 75.32 years (27 509 days) on an eccentric, orbit tilted at 162° to the plane of the Solar System (i.e. a retrograde orbit, at an angle of18° to the plane of the Solar System, but travelling in the opposite direction to the majority of the objects in the Solar System), that takes it from 0.56 AU from the Sun (59% of the average distance at which the Earth orbits the Sun, and inside the orbit of the planet Venus) to 35.1 AU from the Sun (35.1 times as far from the Sun as the Earth, and outside the orbit of the planet Neptune). As a comet with a period of more than 20 years but less than 200 years, Halley's Comet is considered to be a Periodic Comet, and a Halley-type Comet.

The current position and orbit of Halley's Comet. JPL Small Body Database.

Halley's Comet was visited by the European Space Agency's Giotto Probe and the Soviet Vega 1 and Vega 2 probes in March 1986, which were able to determine that the nucleus of the comet was only 15 km across, although it was surrounded by a coma about 100 000 km in diameter, made up of fragments of dust and ice released from the surface as it was heated by the Sun, causing the ices on its surface to sublimate (turn directly from solids to gasses), and that this material comprised 80% water, 10% carbon monoxide, 2.5% methane and ammonia, as well as trace amounts of more complex hydrocarbons, iron and sodium.

Image of Halley's Comet taken by the Giotto Space Probe in 1986 - the first ever photograph of the nucleus of a comet. Halley Multicolour Camera Team/Giotto Project/European Space Agency.

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The Perseid Meteor Shower.

The Perseid Meteor Shower lasts from late July to early September each year, and are expected to be at a peak before dawn on Tuesday 12 August 2025. Viewing will be less than ideal for the Perseids this year, as the meteors peak after the Full Moon on Saturday 9 August. The Perseids get their name from the constellation of Perseus, in which the meteors have their radiant (the point from which they appear to originate). Potentially, at the peak of activity, the Perseid Meteor Shower can produce over 150 meteors per hour, although it is best seen from the Northern Hemisphere, as the constellation of Perseus is near to the North Pole. 

The radiant point for the Perseid Meteor Shower. N Sanu/Wikimedia Commons.

Meteor showers are thought to be largely composed of material from the tails of comets. Comets are composed largely of ice (mostly water and carbon dioxide), and when they fall into the inner Solar System the outer layers of this boil away, forming a visible tail (which always points away from the Sun, not in the direction the comet is coming from, as our Earth-bound experience would lead us to expect). Particles of rock and dust from within the comet are freed by this melting (strictly sublimation, transforming directly from a solid to a gas due to the low pressure on it's surface) of the comet into the tail and continue to orbit in the same path as the comet, falling behind over time.

The Earth passing through a stream of comet dust, resulting in a meteor shower. Not to scale. Astro Bob.

The Perseid Meteors are caused by the Earth passing through the trail of the Comet 109P/Swift-Tuttle, and encountering dust from the tail of this comet. The dust particles strike the atmosphere at speeds of over 200 000 km per hour, burning up in the upper atmosphere and producing a light show in the process.

How the passage of the Earth through a meteor shower creates a radiant point from which they can be observed. In The Sky.

Comet 109P/Swift-Tuttle was discovered independently in July 1862 by the astronomers Lewis Swift and Horace Parnell Tuttle, after whom it is named. The number 109P implies that it was the 109th comet discovered (strictly speaking people had been observing comets for thousands of years, but it was not until the mid-eighteenth century that it was realised that they were predictable objects that returned cyclically), that it is a periodic comet (P - again, most comets are periodic, but the term 'periodic comet' is reserved for those with periods of less than 200 years, since these can be reliably predicted).

Comet 109P/Swift-Tuttle imaged in 1992 during its last visit to the Inner Solar System. The Planetary Society/NASA.

Comet 109P/Swift-Tuttle itself only visits the Inner Solar System once every 133 years, last doing so in 1992, on an eccentric orbit tilted at 113° to the plane of the Solar System (or 67° with a retrograde orbit - an orbit in the opposite direction to the planets - depending on how you look at it), that takes it from 0.95 AU from the Sun (95% of the distance at which the Earth orbits the Sun) to 51.22 AU from the Sun (51.22 times as far from the Sun as the Earth, more than three times as far from the Sun as Neptune and slightly outside the Kuiper Belt, but only scraping the innermost zone of the Oort Cloud). 

The orbit and current position of Comet 109P/Swift Tuttle. JPL Small Body Database Browser.

109P/Swift-Tuttle is next expected to visit the Inner Solar System in 2126, reaching about 22 950 00 km (0.15 AU) from Earth in August of that year. As a comet with a period of more than 20 years but less than 200 years, 109P/Swift-Tuttle is considered to be a Periodic Comet, and a Halley-type Comet.

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