Imagine you give Dr Emmet “Doc” Brown’s DeLorean to an astronomer whose passion consist in observing shooting stars all night long. When would he drive back to the past? Very probably 50 years ago, on November 17, 1966, in Western Northern America 1!

1966 Leonid meteors recorded on a 10-12 minute exposure photography by A. Scott Murrell. Source: Sky & Telescope, November 1995, p. 30.
1966 Leonid meteors recorded on a 10-12 minute exposure photography by A. Scott Murrell. Source: Sky & Telescope, November 1995, p. 30.

On that night, the usually fixed sky turned out to be moving, from the Leonid radiant rise (short after midnight), until twilight. On that night, estimated ZHR for the Leonid meteor outburst range up to 80 000 meteors. Which means an astronomer in good observing conditions could spot up to 10 to 20 meteors PER SECOND! Not surprising it was remembered as an exceptional night by all people that was fortunate enough to observe this dramatic event. A nice compilation of witness testimonies has been published by Peter Jenniskens. Do not hesitate to take a few minutes to read them, and imagine what it could look like. If imagination is not enough, then try to make a simulation of such a meteor storm with MetSim software (developped by Sirko Molau). Install it, configure it, put your screen in the dark, and try to count meteors!

1966 Leonid meteors, showing the radiant effect that was discoveres 133 years ago, during the 1833 Leonid meteor storm. Picture by James W. Young from Table Mountain, California.
1966 Leonid meteors, showing the radiant effect that was discoveres 133 years ago, during the 1833 Leonid meteor storm. Picture by James W. Young from Table Mountain, California.

Due to these spectacular events (other Leonid meteor storms occured in the past, especially in 1833, 1999, 2001 and 2002), the Leonid meteor shower was one of those who helped the more researchers from the past (discovery of radiant, link between comet and meteor showers) and the present (improved accuracy in meteor outburst predictions) to understand the dynamics of meteoroids and the physics at the root of meteor showers. For example, we know now that the 1966 Leonid meteor storm was not linked to the fresh return of the comet 55P/Tempel-Tuttle to perihelion (which was believed until 1998), but from meteoroids released from the comet nucleus 66 years before, during the 1899 perihelion. And we know that a Leonid meteor storm is not expected to happen before 2033-2034…

Leonid shower radiant position in the sky. On the maximum night (November 17, 2016), it will be located in the middle of the loop representing Leo's head, and which looks like a starry question mark.
Leonid shower radiant position in the sky. On the maximum night (November 17, 2016), it will be located in the middle of the loop representing Leo’s head, and which looks like a starry question mark.

This year will be a classical Leonid year. ZHR should range around 15-20, and nothing exceptional is predicted. Furthermore, the gibbous decreasing Moon will create severe light interferences that will erase the dimmer meteors from the sky. But for those who wish to spend a few hours out to try to catch a few meteors per hour coming from 55P/Temple-Tuttle comet, do not hesitate! Leonids can be observed after 1 to 2 am local time, and best rates should be observed before twilight, when the radiant (located in the head of Leo) is higher in the sky. If you spot a meteor, and you want to know if it’s a Leonid or not, just remember that Leonids are part of the fastest observable meteors (their atmospheric entry velocity is 72 km/s), and should thus appear swift, and they apparent path in the sky should originate from Leo’s head (easy to recognize as it looks like star pathedf questionmark). If a shooting star fits these two requirements, you observed a Leonid! Which is a distant brother of the meteoroids that caused the 1966 great show…

Clear skies!

1 other astronomers would also choose October 9, 1933, in Europe (Draconid meteor storm), or November 12-13, 1833, in Northern America again (Leonid meteor storm), depending on subjective preferences.

One comment

  • I witnessed it from Deep Springs that night.
    My friend Danny Ihara’s account on the NASA sit vastly understates the incredible effect.

    Reply to Doug Von Qualen

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