Why do shooting stars always fall in San Lorenzo? The scientific explanation

Why do the so-called “shooting stars” appear above all (but not only) during the ” Night of San Lorenzo “ ? Fortunately, there is a scientific explanation for this historical as well as cyclical astronomical event. First of all, let’s try to understand what the Perseids are :

The 2010 Perseids on ESO’s VLT

The name derives from the word Perseidai (Greek: Περσείδαι ), the sons of Perseus in Greek mythology. The debris stream is called the Perseid cloud and extends along the orbit of comet Swift – Tuttle . The cloud is made up of particles ejected from the comet as it travels along its 133-year orbit. Most of the particles have been part of the cloud for about a thousand years. However, there is also a relatively young dust strand in the stream that was extracted from the comet in 1865, which can give a small early spike the day before maximum rainfall. The size of the cloud near the Earth is estimated to be approximately 0.1 astronomical units (AU) and 0.8 AU along the Earth’s orbit, distributed by annual interactions with Earth’s gravity:

- Prosegue dopo la pubblicità -

The rain of is visible from mid-July of each year, with the peak of activity between 9 and 14 August , depending on the particular position of the stream. The Perseids, therefore, are fragments of the comet that reach us in the same period of each year due to the rotation of the comet itself. During the peak, the speed of the meteors reaches 60 or more per hour. When they come into contact with the Earth’s atmosphere, meteoroids undergo an ablation process, transforming into meteorites . They are absolutely not to be confused with comets or asteroids. They can be seen all over the sky; however, due to the radiant rain in the constellation of Perseus, the Perseids are mainly visible in the northern hemisphere. As with many meteor showers, the visible velocity is maximum in the hours before sunrise, as more meteoroids are collected from the side of the Earth advancing in the flow, corresponding to the local time between midnight and noon, as can be seen in the accompanying diagram. . Although many meteors arrive between dawn and noon, they are usually not visible due to daylight. Some can be seen even before midnight, often skimming the Earth’s atmosphere to produce long light trails and sometimes fireballs. Most Perseids burn in the atmosphere at heights greater than 80 kilometers (50 miles). Below is the list of past astronomical events:

- Prosegue dopo la pubblicità -
Year Active Perseids between Shower peak
2022 July 17 – August 24 12-13 August
2020 July 16 – August 23  [11] 12-13 August (  ZHR  max  100) (  full moon  on 3 August)  [11]
2019 July 17 – August 24 August 12-13  [12]  (  ZHR  max  80) (  full moon  on August 15)
2018 July 17 – August 24 11-13 August  [13]  (  ZHR  max  60)
2017 July 17 – August 24 12 August  [14]
2016 July 17 – August 24 11-12 August  [15]  (ZHR  max  150)
2015 July 17 – August 24 August 12-13  [16]  (ZHR  max  95) (  new moon  on August 14)
2014 July 17 – August 24 August 13 (ZHR  max  68)  [17]  (full moon on August 10)
2013 July 17 – August 24 12 August (ZHR  max  109)  [18]
2012 July 17 – August 24 12 August (ZHR  max  122)  [19]
2011 July 17 – August 24 August 12 (ZHR  max  58)  [20]  (full moon on August 13)  [21]
2010 July 23 – August 24 12 August (ZHR  max  142)  [22]
2009 July 14 – August 24 August 13 (ZHR  max  173) (Estimated peak was 173,  [23]  but a  gibbous moon  faded fainter meteors.)
2008 25 July – 24 August  [24] August 13 (ZHR  max  116)  [24]
2007 July 19 – August  25 [25] August 13 (ZHR  max  93)  [25]
2006 12/13 August (ZHR  max  100)  [26]
2005 12 August (ZHR  max  90  [27]  )  [28]
2004 12 August (ZHR  max  > 200)  [4]
1994 (ZHR  max  > 200)  [2]
1993 (ZHR  max  200–500)  [2]
1992 August 11 (outburst under the full moon on August 13)  [29]
1883 August 9 or earlier  [30] 11 August (ZHR  max  43)  [30]
1864 (ZHR  max  > 100)  [2]
1863 (ZHR  max  109-215)  [2]
1861 (ZHR  max  78-102)  [2]
1858 (ZHR  max  37–88)  [2]
1839 (ZHR  max  165)  [2]

 

Some  Catholics  call the Perseids the ” tears of  San Lorenzo  “, suspended in the sky but which return to Earth once a year on August 10, the canonical date of the martyrdom of that saint in 258 AD  [31]  It is said that the  saint  was burned alive on a grill, and this tradition is almost certainly at the origin of the popular Mediterranean legend according to which shooting stars are the sparks of that fire and that in the night between 9 and 10 August cooled embers appear in the ground under the plants which are known as the “coal of San Lorenzo”. [32]  [33]  The transition to the Catholic saint and his  feastAugust 10 and away from the pagan gods and their festivals, known as  Christianization  , was facilitated by the phonetic assonance of the Latin name Laurentius with Larentia. [34]  [35] In 1836  Adolphe Quetelet  wrote: ” J’ai cru remarquer aussi une frequency plus grande de ces météores au mois d’août (du 8 au 15)” . – ” I think I also noticed a higher frequency of these meteors in August (8 to 15). ”  [36]  After studying the historical records, he predicted a peak on 10 August. He then wrote to other astronomers who confirmed this prediction on the night of August 10, 1837. Quetelet lost his shower due to bad weather. [37]In 1866, after the passage to the Swift-Tuttle perihelion in 1862, the Italian astronomer  Giovanni Virginio Schiaparelli  discovered the link between meteor showers and comets. [37]  The find is contained in an exchange of letters with  Angelo Secchi .

- Prosegue dopo la pubblicità -

References:

  1. ^  Bill Cooke; Danielle Moser and Rhiannon Blaauw (11/08/2012). “NASA Chat: Stay ‘Up All Night’ to Watch the Perseids!” (PDF)  . NASA. p. 55  . Retrieved  2013-08-16  .
  2. ^ Jump up: a  b  c  d  e  f  g  h  Gary W. Kronk . “Observing the Perseids” . Meteor showers online. Archived from the original on 19-07-2018 . Retrieved  2009-08-12  .
  3. ^ Jump up: a  b  c  d  Moore, Patrick; Rees, Robin (2011),  Patrick Moore’s Data Book of Astronomy  (2nd ed.), Cambridge University Press, p. 275, ISBN 978-0521899352
  4. ^ Jump up: a  b  Żołądek, P .; et al. (October 2009), “The 2004 Perseid meteor shower – Polish Fireball Network double station preliminary results”, Journal of the International Meteor Organization , 37 (5): 161–163, Bibcode : 2009JIMO … 37..161Z
  5. ^  Dan Vergano (07/08/2010). “Perseid meteor shower to light up the night sky this weekend  .  ” Usedday.com  . Retrieved  2013-08-12  .
  6. ^  Dr. Tony Phillips (June 25, 2004). “The Perseid Meteor Shower of 2004”  . Science @ NASA. Archived  from the original  on March 20, 2010  . Retrieved  2010-03-12  .
  7. ^ DW Hughes (1996). “Perdita di polvere cometaria: flussi di meteoriti e nuvola di polvere del sistema solare interno”. In J. Mayo Greenberg (a cura di). La connessione della polvere cosmica . Springer Science & Business Media. p. 375. ISBN 9789401156523.
  8. ^  “Perseid Meteor Shower 2018”  . date and time.com  . Extract  30-07-2018  .
  9. ^  “Archived copy”  . Archived  from the original  on 17-08-2015  . Extract  2015-07-20  .
  10. ^  “NASA All Sky Fireball Network: Perseid End Height”  . NASA Meteor Watch on Facebook. 2012-08-11  . Retrieved on  11-19-2012  .
  11. ^ Jump up: a  b  “Perseid meteor shower 2020: When and where to see it in the UK” . Greenwich Royal Museums . 23-07-2020 . Extract  2020-08-02  .
  12. ^  “Perseid meteor shower 2019: when and where to see it in the UK”  . Greenwich Royal Museums  . Retrieved  August 3,  2019  .
  13. ^  Sarah Lewin (9 July 2018). “Perseid Meteor Shower 2018: when, where and how to see it”  . Space.com  . Retrieved  July 20,  2018  .
  14. ^  Sarah Lewin (26 July 2017). “Perseid Meteor Shower 2017: when, where and how to see it”  . Space.com  . Retrieved  July 27,  2017  .
  15. ^  “Perseid Meteor Shower 2016: when, where and how to see it”  . Retrieved  18-07-2016  .
  16. ^  “Meteor Shower 2015”  . NASA  . Retrieved  2015-08-09  .
  17. ^  “Perseids 2014: A Quick Look at Visual Data”  . Imo.net. 08-13-2014. Archived  from the original  on 24-10-2016  . Retrieved  08-13-2014  .
  18. ^  “Perseids 2013: A Quick Look at Visual Data”  . Imo.net. 23-09-2013. Archived  from the original  on 24-10-2016  . Extract  20-04-2014  .
  19. ^  “Perseids 2012: A Quick Look at Visual Data”  . Imo.net. 22-10-2012. Archived  from the original  on 21-04-2014  . Extract  20-04-2014  .
  20. ^  “Perseids 2011: A Quick Look at Visual Data”  . Imo.net. 2011-10-06. Archived  from the original  on 06-11-2013  . Extract  20-04-2014  .
  21. ^  “How to see the best meteor showers of the year: tools, tips and ‘Save the dates’ “  . nasa.gov  . Retrieved  2010-11-16  .
  22. ^  “How to see the best meteor showers of the year: tools, tips and ‘Save the dates’ “  . nasa.gov  . Retrieved  2010-08-12  .
  23. ^  “Perseids 2009: A Quick Look at Visual Data”  . Imo.net. 26-04-2010. Archived  from the original  on 16-10-2016  . Retrieved  2009-08-11  .
  24. ^ Jump up: a  b  “Perseids 2008: A Quick Look at Visual Data” . Imo.net. 06-06-2009. Archived from the original on 24-10-2016 . Retrieved  2009-08-11  .
  25. ^ Jump to: a  b  Perseids 2007: first results  Archived 27-09-2011 in
  26. ^  EAS
  27. ^  “Perseids 2005, visual | IMO”  .
  28. ^  NASA.gov
  29. ^  Brown (1992). “The Perseids 1992. A new outburst announces the return of P / Swift-Tuttle”. WGN  . 20  (5): 192.  Bibcode  :  1992JIMO … 20..192B  .
  30. ^ Jump up: a  b  Corder, H (22 October 1883). “1883Obs ….. 6..338C Page 338” . Adsabs.harvard.edu . 6 : 338. Bibcode : 1883Obs ….. 6..338C . Retrieved  November 3,  2018 .
  31. ^  “Science: tears of San Lorenzo”  . TIME  . 1926-08-23  . Retrieved  2009-08-12  .
  32. ^  (in Italian)  Falling stars and coal under the basil
  33. ^  (in Italian)  The coal of San Lorenzo
  34. ^  (in Italian)  Castrum Inui  Archived  14/08/2016 at the Internet Archive  .
  35. ^  “OUTPUT STARS”  . Student BLOG.
  36. ^  Annuaire de l’Observatoire Royal de Bruxelles  , Volume 4, 1836,  p272  (in French)
  37. ^ Jump up: a  b  Sauval, J., “Quetelet and the Discovery of the First Meteor Showers”, WGN, Journal of the International Meteor Organization , {25} February 1997, pp 21-33
  38. ^  “Curious George: The Little Monkey of Bright Lights”  .

External links 

Wikipedia.org: https://en.wikipedia.org/wiki/Perseids#cite_note-31

- Prosegue dopo la pubblicità -

#astronomy #sanlorenzo #stellecadenti #meteorites

Se ti è piaciuto questo articolo e non vuoi perderti i nostri aggiornamenti pui seguirci anche su Telegram al seguente indirizzo >https://t.me/globochannel<. E' inoltre possibile seguirci su Facebook cliccando "MI PIACE" e poi "segui" su questa Pagina >www.facebook.com/GloboChanneldotcom<. GloboChannel.com è anche su twitter.com/globochannel1, su instagram.com/globo_channe_ita/ e su linkedin.com/company/globochannel.

Articoli correlatiDi più dello stesso autore