Kerr Watch

Number of days writer Richard Kerr has failed to inform his Science readers of the confirmation of nanodiamonds at the YDB: 3 years, 7 months, and 4 days

CT Post Calendar

July 2014
M T W T F S S
« Jun    
 123456
78910111213
14151617181920
21222324252627
28293031  

The Cosmic Tusk Newsletter

Loading...Loading...


From Space with Love: February Fireballs Nothing New

The Great Canadien Fireball Train of February 9, 1913 as painted by Gustav Hahn

See Tusk, December 2, 2010

Just sayin’:

“They all hail from the asteroid belt—but not from a single location in the asteroid belt,” he says. “There is no common source for these fireballs, which is puzzling.”…..

Brown explains: “Back in the 1960s and 70s, amateur astronomers noticed an increase in the number of bright, sound-producing deep-penetrating fireballs during the month of February. The numbers seemed significant, especially when you consider that there are few people outside at night in winter. Follow-up studies in the late 1980s suggested no big increase in the rate of February fireballs. Nevertheless, we’ve always wondered if something was going on.”

Indeed, a 1990 study by astronomer Ian Holliday suggests that the ‘February Fireballs’ are real. He analyzed photographic records of about a thousand fireballs from the 1970s and 80s and found evidence for a fireball stream intersecting Earth’s orbit in February. He also found signs of fireball streams in late summer and fall. The results are controversial, however. Even Halliday recognized some big statistical uncertainties in his results.  – NASA Press Release, February 22, 2012

 

 

An illuminating exchange from the Kobres’ Archive:

Bob and Peter,

Below is an email from Bob Kobres describing a procession of meteors very similar to the procession of Oct 4, 199?, described to me by Peter Brown. I send this to you, Peter, to spur you to publish a summary of the Oct event.As Bob points out, the Feb events may be linked, and there might be a debris stream that may have produced similar activity (with the 1.62 yr period) in 1926, 1947, 1960, 1973, 1981, and 1994, in addition to those observed in 1913 and 1934, and may yet produce activity in Feb of 2007. Going through my latest list of asteroid streams (Icarus 146, p453, 2000), I find nothing that comes close to the orbit by Wylie. The only streams that come near the Earth with theoretically active radiants in early Feb all have radiants below the horizon by early evening, and/or have radiants such that the meteors should be moving south to north in North America and Canada.

 

 

All very interesting….

 

Jack

 

————————————

Hi Jack, it has probably been a decade since I last spoke with you about the 1913 fireball event and its possible relation to your February centered grouping of early evening meteors. I noticed that you had published a paper related to this recently (Icarus 146) and thought that you might have some additional information regarding the 1913 event. I’m particularly interested in C. C. Wylie’s interpretation (last excerpt below) of the fall, as the 1.62 year period he arrives at would seem to place a debris stream near Earth in 1913, 1934, and 1947.

 

 

The articles that the excerpts below are from are available and searchable

here:

http://djvued.libs.uga.edu/chant/

or with less convenient searching here:

http://abob.libs.uga.edu/bobk/chant/

 

Thanks.

bobk

 

~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~

THE GREAT METEOR OF 9TH FEBRUARY, 1913

By W. H. S. Monck

 

IN the Session of 1902-3 I laid before the Society in conjunction with the late Mr. Arthur Harvey, a catalogue of aerolites or meteors that had fallen to the earth in the solid state, and we both expressed our opinion that they came in recurring showers like ordinary meteors, though the richest meteor-showers seemed to be unproductive of aerolites, while much fainter ones were often accompanied by aerolites or fireballs. It was natural under the circumstances to refer to this catalogue in connection with the great meteor of 9th February, 1913, and I found there three actual stone falls on the 10th of February, one at Nanjemoy, Maryland, in 1825, another at Girgenti, Sicily, in 1853, and a third at Madrid, Spain, in 1896, besides which Mr. Harvey has in the supplemental list one at the Isle of Oleron. France, in 1875. There are, likewise, two falls on the l2th of February and two more on the 13th, one of the former pair being at Homestead, Iowa, in 1875, just two days after the fall at the Isle of Oleron, France.

 

Turning back to the Monthly Notices of the R.A.S. for the

year 1865-6, I find the late Mr. A. S. Herschel writing, “Detonating

Meteors were observed on the 10th February, 1772-, by

Brydone; on the 11th of February, 1850, by the present Astronomer

Royal, and on the 9th of February, 1865, by a friend of the

writer at Bangalore, S. India, all of which probably belonged to

the zone of meteors circulating round the sun.” (XXVI.

p. 211).

 

A list of eight American meteoric fireballs, an account of which

was given by Professor Daniel Kirkwood. in 1877, included one on

February 8, 1877, but as he had only one observation of this fire-

ball he was unable to make his computations with regard to it. A

brilliant day-light meteor was seen 17 years later on February 8,

1894. It was seen almost at noon by Dr, A. A. Rambaut, Astronomer

Royal of Irelaud, at Dunsink, near Dublin, and also by Mr.

Wood, near Birmingham, and others. Its path was calculated

by Dr. Rambaut and also by Mr. Wood, according to both of

whom it was first seen at a height of about 80 miles over the

Irish Sea and was lost sight of over Yorkshire after descending

to less than one-fourth of that height. This is not a bad collection

and could no doubt have been added to if I had pursued my

inquiries farther; but I may give one mine example. On February

11th 1905, three bright meteors were doubly or more than doubly

observed and paths determined for them by Mr. Denning, but

they do not seem to have been as brilliant as most of those

already referred to. There were, however, material differences

between their radiants as computed by Mr. Denning. Two

meteor-showers active on the same night is not unusual but it

would be unusual to find both of them rich in fireballs. Yet

there is some reason for thinking so in the present instance.

There is certainly no fireball shower in February previous to the

8th of that mouth, but the ending is much less definite than the

beginning and those on the 12th and 13th may perhaps have had.

a different source from those on the 8th, 9th and 10th.

 

 

~~~~~~~~~~~~~~~~~~~~~~~~~~~

The Meteoric Display of February 12, 1934: A Preliminary Report

By H. H. Nininger

 

A remarkable meteoric display occurred about 9:20 o’clock, M.S.T., on the

evening of February 12, 1934, visible from the States of Nebraska,

Wyoming, Montana, Idaho, Utah, Colorado, Kansas, Iowa, and South Dakota.

This flight was unusual in several particulars as follows:

 

1st: The meteor or meteors continued luminous through a much longer arc

than is commonly the case, coming into visibility at least as far west as

eastern Idaho or southwestern Montana and continuing visible as far east

as eastern Nebraska–over a distance of not less than 700 miles. The

extreme limits have not yet been definitely determined. The meteor may

have come into view at a point even farther west than has been indicated.

 

2nd: The flight was peculiar, also in its multiple nature. It consisted of

not less than three distinct units during the latter half of its visible

course.

These units traveled, not in a procession, but in a more or less fixed

formation.

 

3rd: The flight was much slower than is the movement of ordinary meteors,

being only about 31/4 miles per second in the middle part of its visible

course, where it was timed very carefully by a competent observer through

a distance of about 160 miles.

 

4th: All observers who have been interviewed agree that the meteor was not

sufficiently bright to light up the landscape noticeably. Even those who

were near the course compare the light to that of Venus at her best, but

state

that the meteors were apparently larger than the planet. This circumstance

seems a bit strange in view of the fact that the flight was visible from

points

as far as 400 miles south of its course. It is probable, indeed almost

certain,

that the earlier half of the flight was more brilliant than the latter half.

It is

probable also that the three fireballs seen by the observers interviewed,

had

resulted from the disruption of a single mass, the disruption occurring at

about the mid-point of the luminous flight; however, this matter has not yet

been settled.

 

5th: No noise was heard by the numerous witnesses interviewed along the

line of flight between Torrington, Wyoming, and Burwell, Nebraska, with the

exception of two persons in Burwell.

 

The three meteors which traveled together through the last 200 miles

gradually grew dimmer until their redness faded out at an altitude which has

not yet been definitely determined but which is known to have been several

miles above the ground. A bright moon and the meteor’s slow movement

would certainly in part account for its reduced luminescence.

 

As he interviewed the numerous witnesses to this phenomenon, the writer was

impressed by its resemblance to “The Meteoric Procession of February 9,

1913,” as reviewed by William 15. Pickering in POPULAR ASTRONOMY,

Vols. 29 and 30, 1921 and 1922. Both phenomena resemble each other very

closely as concerns the time of year, time of day, direction of flight,

velocity,

luminescence, and angle of descent. Both were multiple meteors and both

were of unusual duration.

 

No fragments from this fall have as yet been reported.

 

Do the unusual displays of February 9, 1913, and of February 12, 1934, have

any special significance, or do they bear any relation to each other?

 

~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~

The Radiant and Orbit of the

Meteors of February 9, 1913

By C. C. WYLIE

 

The meteors of February 9, 1913, are among the best known of modern

times, being mentioned in general textbooks, books on meteors and

meteorites, encyclopedias, histories, and popular books. More than 140

reports are available, nearly all having been collected and published by

Professor C. A. Chant, of the University of Toronto. Had he not made

that prompt investigation, this study would have been quite impossible.

 

THE POPULAR EXPLANATION IS UNTENABLE

 

The popular explanation of the phenomenon is that a cluster of fireballs

travelled from Saskatchewan across. North America, and over the

Atlantic to the equator, a distance of some 5700 miles. Several

considerations, of which we will mention four, make this explanation

untenable.

 

First, the letters give the descriptions we would receive from intelligent

people on a shower of meteors with a radiant in the north-north-

west. They do not describe what the popular explanation assumes–a

cluster of fireballs rising from behind objects on the horizon in the. west-

northwest, crossing the sky on a great circle, and going behind objects

on the horizon in the east-southeast.

 

Second, the disappearance of a shadow-casting meteor behind objects

on the horizon is impressive, and observers who see it comment on the

spectacle when they write. The fact that no observer reports seeing this

shows that few, if any,, bright meteors went behind objects on the

horizon for the more than 140 observers reporting. This, in turn, shows

that the paths cannot have been especially long, for we have received

such reports on several meteors.

 

Third, only shadow-casting meteors come low enough for detonations.

The shooting stars coming from the same radiant must have ended

twenty-five or thirty miles higher than the detonating meteor. Any

conclusions based on the assumption that the shootings stars and the

detonating meteor were at the same height when brightest must be

erroneous.

 

Fourth, the kinetic energy of a meteor about as bright as the full

moon, and travelling; at a speed of seven miles per second at a height of

about twenty-five miles, is sufficient to maintain that velocity against the

air resistance for eight to ten miles. A drop in speed lessens the air

resistance, but it also lessens the kinetic energy, and the meteor drops

into denser air. When a meteor no brighter than the full moon has

dropped to a speed of seven miles per second, and a height of

twenty-five miles, the end of its. path is very near.

 

The popular explanation has been quite generally accepted, but

Fisher and Hoffmeister have questioned whether it is completely correct.

Neither, however, appears to challenge the assumption of long

paths extending from horizon to horizon and neither makes any

determination of the radiant or a calculation of a real path.

 

The Fireballs of February 9, 1913

 

The following are the more important fireballs which probably fell

from the leading radiant on that night:

 

First, a detonating meteor which fell over Ontario at 9:06 1/2 P.M., 75th

meridian time.

 

Second, a shadow-casting meteor observed from Ann Arbor, Michigan,

at 10:15 P.M., C.S.T. (11:15 P.M., 75th meridian time).

 

Third, a spectacular fireball observed from Bermuda at 10:00 P.M.,

Atlantic time (9:00 P.M., 75th meridian time).

 

Fourth. a shadow-casting meteor observed in Ontario at 1:25 A.M.. 75th

meridian time, February 10.

 

Fifth, a daylight detonating meteor which fell in Patagonia at 6:00 A.M.,

February 10.

 

In addition to these spectacular meteors, several groups of shooting

stars were observed, among them the following:

 

Fort Frances, Ontario, 9:00 P.M., C.S.T. (10:00 P.M., 75th meridian time).

A string of forty or so meteors, followed after five minutes; by a string

of eight, passed north of overhead.

 

Mortlach, Sask., 7:10 Mountain time (9:10 P.M., 75th meridian time).

“Must have been hundreds.”

 

Watchung, New Jersey. (Time not given, returning from church). Saw

seven distinct meteors, two burst.

 

Pense, Sask., 7:00 M.S.T. (9:00 P.M., 75th meridian time). Considerable

number of meteors seen singly and in groups.

 

Ontario. Shooting stars unusually .bright, or in unusual numbers, were

reported at various times from 7:30 P.M., February 9 to 2:20 A.M.,

February 10. The greatest number were noticed immediately after

the fall of the detonating meteor, as people were looking up then.

Only two or three were definitely not from the leading radiant.

 

Atlantic Ocean. Five ships reported meteors in unusual numbers, at times

varying from 8:51 to 10:01 P.M., 75th meridian time. For one ship

the shower continued thirty minutes. Three of the five ships reported

the general direction of motion as follows: “from north to. south,”

“from west by north to southeast,” and “from west of the constellation

Orion toward the south.” These directions are all in general

agreement with the leading radiant.

 

England. Bright meteors were unusually numerous according to

Denning. No time or radiant is given.

 

. . .

 

THE ORBIT

 

>From the heliocentric radiant and velocity the orbit about the sun was

computed. The orbit is direct, and it resembles the orbits of the small

asteroids which come close to the earth, rather than those of comets.

However, the shower of shooting stars. in connection with this fall

indicates a swarm of small particles which is characteristic of comets

rather than asteroids. The following are the elements obtained.

 

[semimajor axis] a = 1.38

[eccentricity] e = 0.328

[argument of perihelion] w = 220.ø3

[longitude of asc. node] O = 320.ø8

[inclination] i = 17.ø5

[period] P = 1.62 years

 

SUMMARY

 

The meteoric display of February 9, 1913, was a shower of fireballs

and shooting stars from a radiant in the north-northwest. It was not a

procession of fireballs moving over an unusually long path. The most

spectacular meteor of the display was a detonating meteor which fell in

Ontario at 9:06 P.M., 75th meridian time.

 

The approximate radiant is indicated by three references to Cassiopeia,

and it was computed from the paths of the Ann Arbor and Bermuda

fireballs, together with the direction of travel of overhead meteors

in Ontario.

 

The true geocentric radiant was computed from the detonating

meteor, and the Ann Arbor meteor observed by an astronomer, as

follows: the projected path of the detonating meteor was drawn using

reports which gave the direction of the path from overhead. The height

of the real path at various points was obtained from two measurements

of the apparent height. The directions of the points of appearance and

disappearance were obtained by selecting the reports which appeared to

give these directions the most carefully. The endpoint was obtained more

accurately from the detonations as follows: without using any estimates

of time this point was made to agree with the reports stating whether

the detonations occurred during or after the display of shooting stars.

The approximate velocity was obtained from the estimates of duration.

An accurate value for the velocity was obtained on the assumption that

the Ann Arbor meteor came from the same radiant and with the same

velocity as the detonating meteor. With this value of the velocity, the

altitude of the apparent radiant was corrected for zenith attraction and

the right ascension and declination of the true radiant were obtained.

 

>From the right ascension and declination of the radiant and the apparent

velocity, the geocentric velocity and the heliocentric velocity

were computed. The right ascension and declination of the heliocentric

radiant were computed, and, following this, the elements of the orbit

about the sun. The orbit is direct, and it resembles the orbits of the

small asteroids which pass inside the orbit of the earth rather than the

orbits of the comets.

 

UNIVERSITY OF IOWA, APRIL 27, 1939

~~~~~~~~~~~~~~~~~~~~~~~~~

Leave a Reply

  

  

  

You can use these HTML tags

<a href="" title=""> <abbr title=""> <acronym title=""> <b> <blockquote cite=""> <cite> <code> <del datetime=""> <em> <i> <q cite=""> <strike> <strong>