Showing posts with label Meteors. Show all posts
Showing posts with label Meteors. Show all posts

Monday, 31 August 2026

The Alpha Aurigid Meteor Shower.

The Alpha Aurigid Meteor shower occurs each year between 25 August and 6 September, and is expected to peak between 1.00 am and dawn on 1 September (this should be roughly the same wherever you are, as our 24 hour clock is derived from the motion of the Earth). However the shower is notoriously hard to observe, having been recorded only in the years 1911, 1929, 1930, 1935, 1979, 1980, 1986, 1994 and 2007 (some of these observations occurred before the 'official' discovery of the shower by Cuno Hoffmeister and Artur Teichgraeber in 1935, but have subsequently been linked to the shower). To make matters worse, the peak of the shower will fall slightly after the New Moon on 28 August, which would hamper the viewing of any meteors that do appear. The shower has its radiant point (the point from which the meteors appear to radiate) in the constellation of Auriga, close to the star Alpha Auriga (hence the name), which is a circumpolar star, permanently above the horizon in the Northern Hemisphere, but difficult to spot from the Southern Hemisphere.

The radiant of the Alpha Aurigid Meteors. Copper Mountain Mesa.

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 Aurigid Meteors are made by the Earth passing through the trail of Comet C/1911 N1 (Keiss),  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 C/1911 N1 (Keiss) was discovered on 6 July 1911, by astronomet Carl Clarence Keiss, at the Lick Observatory on the summit of Mount Hamilton, in the Diablo Range just east of San Jose, California. The name C/1911 N1 (Keiss) implies it was the first (1) comet (C/) discovered in the first half of July 1911 (period 1911 N), and that is was discovered by Keiss.

A photograph of Comet C/1911 N1 (Keiss) taken by French Astronomer Ferdinand Quénisset at the Camille Flammarion Observatory to the south of Paris on 29 July 1911. The photograph is a single 78 minute exposure which tracked the comet; the elongated objects are stars which moved during the course of the exposure. Wikimedia Commons.

Comet C/1911 N1 (Keiss) completes one orbit every 2497 years on an eccentric orbit tilted at 148° to the plane of the Solar System, that takes it from 0.68 AU from the Sun (68% of the average distance at which the Earth orbits the Sun, and slightly inside the orbit of the planet Venus) to 367 AU from the Sun (367 times as far from the Sun as the Earth, and more than three times the distance at which the planet Neptune orbits the Sun). The comet last visited the Inner Solar System in 1911. As a comet with an orbital period of more than 200 years it is considered to be a Long Period Comet.

The current position and orbit of C/1911 N1 (Keiss). JPL Small Body Database.

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Monday, 17 August 2026

The Kappa Cygnid Meteor Shower.

The Kappa Cygnid Meteor Shower is visible some years between the months of June and September, peaking between 3 and 25 August, with the best peak rate generally falling before dawn on 18 August, when the shower can produce 2-3 meteors per hour, with these tending to be bright fireballs with multiple fares. The meteor shower gains its name from the star Kappa Cygnus, which it is close to at the peak of its activity, and which is circumpolar in the Northern Hemisphere (i.e., close to the North Pole, and permanently above the horizon), although generally invisible in the Southern Hemisphere. If the shower does appear, viewing should be reasonably good, as activity will peak two days before the first quarter Moon, which will be in the constellation of Virgo, providing minimal light interference. However, the meteor shower is notoriously erratic, not being seen every year; it was last seen in the Augusts of 2020 and 2021, and before that in 2013 and 2014, then before that in 2007.

The radiant point of the Kappa Cygnid Meteor Shower. The Sky Live.

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 source body of the Kappa Cygnid Meteors remains somewhat of an enigma. The low number of asteroids, and their irregular arrival, suggests they are an old shower potentially derived from an object no longer visiting the Inner Solar System, whereas the brightness of the meteors suggests a younger origin. One possible solution to this is that they are derived from a body whose orbit undergoes a sinusoidal oscillation, something which can be caused if a body is forced into an orbital resonance with a larger body, often Jupiter in our Solar System. 

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

One potential parent body for the Kappa Cygnid Meteors which has been suggested is 2008 ED69, an asteroid which has an orbit with a 2:1 resonance with that of Jupiter and an orbital period of 4.96 years, which is thought to have been pushed into and out of Earth-crossing orbits repeatedly over the past 6000 years. However, more recent studies have established that the Kappa Cygnid Meteor Shower has an orbital period of 7.12 years and is locked into a 5:3 orbital resonance with Jupiter, ruling out 2008 ED69 as a potential parent body.

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Tuesday, 23 June 2026

The June Bootid Meteor Shower.

The June Bootid Meteor Shower is visible each year between 26 June and 2 July, typically peaking on 27 June. This meteor shower if highly unpredictable in nature, with most years producing very few meteors, but the shower occasionally having peak years, in which hundreds of meteors are visible each hour; the most recent major peak year happened in 1998 (a smaller peak was recorded in 2004), with the three peaks prior to that happening in 1927, 1921, and 1916. The shower has a radiant point (point from which the meteors appear to radiate) in the constellation of Boötes, close to the North Pole, making the shower possible to spot from anywhere in the Northern Hemisphere, but hard to see in the Southern Hemisphere. Unfortunately, this year's peak activity comes only two days before the Full Moon on 29 June, which means that good observation of the meteors may be hampered by the brightness of the Moon.


The radiant point of the June Bootid Meteor Shower. Space Weather.

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 June Bootids Meteor Shower is caused by the Earth passing through the trail of comet 7P/Pons-Winnecke, 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. 7P/Pons-Winnecke visits the Inner Solar System every 6.37 years, most recently in May 2021, and last came close to the Earth in 1939.

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

7P/Pons-Winnecke was discovered on 12 June 1819 by French astronomer Jean-Louis Pons, then based at Marseilles Observatory, and rediscovered by Friedrich August Theodor Winnecke at Pulkovo Observatory near Saint Petersburg. The designation 7P/Pons-Winnecke implies that it was the seventh comet discovered (7/ - 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), and that it was discovered by Pons and Winnecke.

7P/Pons-Winnecke immaged on 23 September 2015 from Kiev, Ukraine. The image is a single 300 second exposure, with the slightly elongate objects being stars that have moved over the course of the exposure. Alexander Baransky/Kiev Comet Station/Fachgruppe Kometen.

Comet 7P/Pons-Winnecke currently completes one orbit every 2326 days (6.37 years) on an eccentric orbit tilted at 22.3° to the plane of the Solar System, that takes it from 1.26 AU from the Sun (126% of the average distance at which the Earth orbits the Sun) to 5.61 AU from the Sun (5.61 times as far from the Sun as the Earth, and slightly outside the orbit of Jupiter). As a comet with a period of less than 20 years with an orbit angled at less than 30° to the plane of the Solar System, 7P/Pons-Winnecke is considered to be a Jupiter Family Comet.

The orbit and current position of 7P/Pons-Winnecke. JPL Small Body Database.

This orbit means that 7P/Pons-Winnecke occasionally comes close to the Earth, with the last close approach having happened on 1 July 1939, when it reached a distance of 0.11 AU from the Earth (11% of the distance between the Earth and the Sun, or 16 052 000 km). The comet will next come close to us in June 2062, when it will reach a distance of 0.17 AU from the Earth.

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Monday, 8 June 2026

The Daytime Arietid Meteor Shower.

The Arietid Meteor Shower lasts from mid April till late June each year, and is expected to peak before dawn on Wednesday 10 June this year, and originating (appearing to come from) the constellation of Aries. Meteors from this shower can be very bright, leading to the label 'Daytime' Meteors (i.e. meteors that can be seen during the day), although the majority are quite dim, and can be hard to spot. At its peak, the shower can produce about 50 meteors per hour. This year that peak will coincide with a Waning Crescent Moon, which would not normally present a great deal of interference. However, the Moon is also in the constellation of Aries at this time, which may hamper viewing.

The origin point for the Aried Meteors seen from the Northern Hemisphere in early June. Spaceweather.

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 origin of the Arietid Meteors is unclear. No body has been confidently identified as the source of the Arietid Meteors, though both the asteroid 1566 Icarus and the comet 96P/Machholz have been suggested. 

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

Though the Arietid Meteors can be hard to see, it may be possible to 'hear' them using an FM radio. In order to do this it will be necessary to find a frequency between 88.0 and 108.0 MHz without any transmissions or significant static (this may not be possible in urban areas). Meteors passing though the atmosphere generate radio waves at these frequencies, which can be heard as 'bumps' or 'chirps'. More detailed observations can be used if the radio set-up has a directional antenna, allowing the observer to concentrate on a particular part of the sky (this is essentially how radio telescopes work).

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