From Soul to Rock

How our understanding of meteors has evolved

Early interpretations of meteors

• a person's soul on its way to the afterlife• the spirits of shamans travelling to the afterlife• the sinful souls of the deceased• omens of sickness and death• the faeces of stars• stars which suddenly moved• if you see a falling star, your wish will be fulfilled

Historical Meteor Displays

• Annales Seligenstadenses AD 1122: Innumerable stars seemed to fall

and as if to rain down over the whole Earth, on the day before the Nones of April

Probably a reference to an intense outburst from April's Lyrid shower

Dynasty Han, Reign Yuan-yan, Year 1 Month 4 Day Ding-you.

At the hour of rifu, the sky was cloudless. There was a rumbling like thunder. A meteor with

a head as big as a fou, and a length of some ten-odd zhang, colour bright red and white went southeastward from below the Sun.

In all directions, meteors, some as large as basins, others as large as hens’ eggs brilliantly rained down. This only ceased at evening twilight.

An event similar to the Chelyabinsk fireball of Feb 2013 ?

Joshua 10:11

• “The Lord cast down great stones from heaven upon them“

• (although other translations have “hailstones” rather than “stones”)

How did early scientists explain Shooting Stars ?

- they believed that they were related to the weather, rather than to astronomy

Meteor-ology

- the study of the weather

Why shooting stars couldn’t be related to astronomy

• No stars had gone missing• The heavens are perfect

Antoine Lavoisier (1769)

"Stones cannot fall from the sky, because there are no stones in the sky!“

Triangulation (1798)

- revealed that meteors were at altitudes ~ 80-100 km

26 April 1803 : L’Aigle meteorites

Jean-Baptiste Biot concluded that these had indeed fallen from the sky

1833 meteor storm

- seen all along the east coast of North America

Denizen Olmstead

Noticed that meteors appeared to radiate from the constellation of Leo and suggested that a cloud of particles had approached the earth from that direction in space

Meteor paths projected against the sky background appear to radiate outwards

Adolph Quetelet

Noticed that many meteors in early August 1835 & 1836 radiated out from Perseus – the Perseid meteor shower

In July 1862, Swift discovered a new comet. Independently discovered by Tuttle. Named comet Swift-Tuttle

Giovanni Schiaparelli

Investigated orbit of Perseid meteors

Perseid orbit

Schiaparelli realised orbit of Perseid meteors similar to that of comet Swift-Tuttle, suggesting a link between comets & meteor showers

In late Dec 1865, Tempel discovered a new comet. Independently discovered by Tuttle. Named comet Tempel-Tuttle

Maths problem

1866 + 33 =

1899• Everyone was told that there would be a big

meteor storm in November 1899 !• Nothing exceptional seen• "the worst blow ever suffered by astronomy in

the eyes of the public“ - C P Olivier

In Nov 1866, there was another Leonid meteor storm, 33 years after that of 1833. In addition, comet Tempel-Tuttle was found to have an orbit similar to that of the Leonids

Examples of how meteors are referenced in song lyrics

Musical Interlude

You’re a shooting star I seeA vision of ecstasyWhen you hold me, I’m aliveWe’re like diamonds in the sky

(Diamonds – Rihanna)

Catch a falling star and put it in your pocket. Never let it fade away. Catch a falling star and put it in your pocket. Save it for a rainy day.

(Catch a Falling Star – Perry Como)

Waiting for a star to fallAnd carry your heart into my armsThat’s where you belong In my arms, baby, yeah

(Waiting for a Star to Fall – Boy Meets Girl )

I'm wishing on a star to follow where you areI'm wishing on a dream to follow what it means

(Wishing on a Star - Rose Royce)

A falling star fell from your heart and landed in my eyesI screamed aloud, as it tore through themAnd now it's left me blindThe stars, the moon, they have all been blown outYou left me in the darkNo dawn, no day, I'm always in this twilightIn the shadow of your heart

(Cosmic Love – Florence & the Machine)

I’m a shooting star leaping through the skyLike a tiger defying the laws of gravityI’m a racing car passing by like Lady GodivaI’m gonna go go go There’s no stopping me

(Don’t Stop Me Now – Queen)

You light, the skies up above meA star, so bright you blind meDon't close your eyesDon't fade away Don't fade awayYeah you and me we can ride on a starIf you stay with me girl, we can rule the world

(Rule The World – Take That)

You're racing like a fireball, dancing like a ghostYou're Gemini and I don't know which one I like the mostMy head is gettin' broken and my mind is gettin' bustBut now I'm comin' with you down the road of golden dustOh my love, it's a long wayWhere you're from it's a long way?

(Fireball – Deep Purple)

I saw two shooting stars last nightI wished on themBut they were only satellites !Is it wrong to wish on space hardware ?

(A New England – Billy Bragg)

Rev William Ellison

No Leonid storm occurred in Nov 1932 or Nov 1933 ... but on Oct 9 1933, Rev William Ellison (Armagh) observed a storm from the Draconid meteor shower

Bernard Lovell

In the late 1940s, Lovell set up surplus wartime Army radar equipment at Jodrell Bank and showed that meteors could be detected at radio wavelengths (including during the daytime)

George Alcock

Alcock had been a leading meteor observer in the 1930s and 1940s, but mistakenly believed that the success of Jodrell Bank meant there would be nothing more for amateurs to do

Leonids 1966

Dennis Milon's activity curve for the 1966 Leonid meteor storm

A question about the Leonid storm asked by a "Mr R Scagell"

BAA meeting 1966 Nov 30

Opening a discussion, <name> said that since the Leonids went back to the year 902 and

earlier, it seemed that the swarm must be the same one; surely the comet could not keep on

producing meteors in this way ?

A 1978 photo that shows "Mr R Scagell" (and a G Fennimore)

Leonid predictions for 1998-1999

A graphic (created by Donald Yeomans) used during the 1990s to attempt to predict whether 1998 and/or 1999 would produce meteor storms

Leonids 1998Date: 1998 Nov 16-17Observer: Tony MarkhamTimes: 03:25-06:20 UT (2 hr 55 min)LimMag:5.3 at best, sometimes no stars visibleSky: Significant cloud issues up to 05:00

275 Leonids and 4 sporadics seen99 + were mag 0 or brighter- The “Leonid Fireball Storm”

The best guess had been that Leonid rates in 1998 would peak on the evening of Nov 17th, so this outburst of bright Leonids during the previous night was a big surprise

But not actually a storm !

To qualify as a storm, the ZHR needed to reach 1000. The ZHR was kept low by the low number of fainter Leonids

It shouldn’t have been a surprise

A strong display of bright Leonids had been seen from Asia in 1965 (33 years earlier) - need to take into account outbursts seen from outside Europe & N America (a meteor storm had also been seen from China in 1901)

Asher & McNaught : a new approach

• Particles ejected by Comet Tempel-Tuttle at each return will be in separate “dust trails”

• Work out how close Earth will pass to each dust trail

• Predict a close encounter with the 1899 trail at 02:08 GMT on 1999 Nov 18

Whereas other meteor astronomers had focussed on how close the Earth would pass to the orbit of comet Tempel-Tuttle, David Asher & Rob McNaught took a different approach

Leonids 1999

A storm did occur - within 4 minutes of the time predicted

Asher & McNaught : dust trail predictionsTime (GMT) Trail Predicted ZHR1999 Nov 18, 02:08 3-rev 5002000 Nov 18, 03:44 8-rev 30?

2000 Nov 18, 07:51 4-rev 20? 2001 Nov 18, 10:01 7-rev 1,500?

2001 Nov 18, 17:31 9-rev 15,0002001 Nov 18, 18:19 4-rev 15,0002002 Nov 19, 04:00 7-rev 15,000

2002 Nov 19, 10:36 4-rev 25,0002006 Nov 19, 04:45 2-rev 100Note that the 2001 & 2002 storms occurred the night *after* the closest approach to the comet's orbit

Photography & Triangulation

A (manually intensive) camera & rotating shutter system used for metror imaging in the 1960s and 1970s.

Video observing

Video cameras outside William Stewart's house in Cheshire. Software on connected PC makes system highly automated

Video camera networks

Groups of observers point their cameras at the same volume of the upper atmosphere

2015 Apr 10 Fireball

Trajectory of fireball triangulated using images from two different video cameras of the NEMETODE group

Altitude and Speed

Orbit for 2015 Apr 10 Fireball

Having determined its speed & atmospheric trajectory, working backwards gives its former solar system orbit

Meteor trajectories

A graphic created by UKMON showing locations of meteors they have imaged

The big picture

From the EDMOND database (http://cement.fireball.sk/edmond-en/): Each dot shows the direction from which a particular triangulated meteor approached the Earth. Can see clusters/streaks near the radiants of the major meteor showers. Dots are colour coded to show meteor speeds

Meteor Spectra

Camera with Diffraction Grating (Bill Ward)

Spectrum of a Taurid fireball captured by Bill Ward

Perseid spectrum

Intensity plot for a Perseid spectrum (green to near infrared) captured by Bill Ward

Perseid spectra comparisons

Meteor Shower/Sporadic comparisons

Comparison of 5 colourised spectra captured by Bill Ward

Unknowns include

• Relationship between spectra and ...• Meteor altitude• Meteor speed• Meteor particle size• Meteor shower involved• Solar System origin• Stage of meteor

From a video of a Taurid fireball recently captured by Bill Ward - shows 2 spectra from different pieces of the fireball

From Soul to Rock