When Meteors Graze the Sky
If I were just getting started in astronomy, who knows what field would have attracted me? In the 1960s it was comets, and I have no regrets. And notwithstanding the truism that there are no ifs in history, it is possible that I would have chosen meteors instead. Besides, meteors and comets are closely related.
Comet C/2006 P1 (McNaught) taken from Victoria, Australia 2007. Credit: Creative Commons, CC BY-SA 3.0Each time a comet rounds the Sun, tiny specks of dust come off its surface. These specks of dust orbit the Sun in the same orbit as the parent comet, but when the Earth crosses that orbit, those specks of dust may enter the atmosphere and burn up. Thus, while we may spot a comet but once in its orbit, its meteors we can see every year.
Click and scroll on this interactive display of the Perseid meteoroid stream:
2017 Geminid meteor. Credit: David LevyBecause of that, throughout the year we are treated to very good shows of meteors. But each year, the same meteor shower is different. On August 12 this year, for example, I saw 22 Perseid meteors on the night of maximum, a lot less than the 112 I counted on August 12, 1962 from my grandfather’s country home at Jarnac, Quebec. On that fateful night the meteors appeared to fall into Jarnac pond, then float down through streams to the Ottawa River and hence to the St. Lawrence. Years later this thought reminded me of Jean Cabot enjoying a rich Perseid meteor shower from the Gulf of St. Lawrence. No wonder the Perseids are nicknamed the Tears of St. Lawrence.
For those readers who like to save these articles, here is a listing of the year’s ten best meteor showers.[one_half]
1) Quadrantids
These meteors peak just a day or two after New year’s, starting the year off with a bang, as it were. Their maximum is on the morning hours of January 3, but even though it is one of the best showers of the year, it lasts only a few hours. The shower is associated with the now deceased comet 2003 EH1 and its meteors radiate from the archaic constellation Quadrans Muralis., now a part of Boötes.
2) Lyrids
This magnificent shower, whose meteors emanate from Lyra, started badly for me. On April 22 and April 24 I was out, seeing one bright meteor the first night and none the second night. “This was the most disappointing failure I have ever had,” I wrote in my diary at the time. I have had finer failures since then, but actually these observing sessions from my youth were quite a success! Over the years I have enjoyed some lovely Lyrid sessions. The best one was April 23, 1976. That was the night I asked myself if any of the authors whose writings I enjoy have enjoyed these meteors. That was the night I began my interest in the nigh sky and English Literature. These meteors derived from Comet Thatcher from 1861.
3) Eta Aquarids
Just two weeks after the Lyrids, the Eta Aquarids, radiating from Aquarius, appear on the morning of May 4. They come from Halley’s comet, the most famous comet of all. The also provided the brightest meteor I have ever photographed.
4) Delta Aquarids
The first of two major summer showers, The Delta Aquaruids, also radiating from Aquarius, peak on July 27 when the Earth crosses the orbit of Periodic Comet Machholz. Astronomers are not certain that this is the parent comet, but it is the leading candidate. This is my favorite “teaching meteor shower”. For several years during the 1960s, I led many children as they counted these meteors.
5) Perseids
This is the second-best meteor shower of the year. Peaking on August 11 or 12, this shower can produce more than 100 meteors, radiating from Perseus, on a good night. The shower is derived from Comet Swift-Tuttle, which was discovered in 1862 and returned in 1992.[/one_half][one_half_last]
6) Orionids
Like the Eta Aquarids, these meteors are derived from Halley’s Comet. They peak on October 21 but there is a second maximum on October 24. It is a very interesting meteor shower; its meteors radiate from Orion. I photographed one of these meteors passing directly in front of the Andromeda Galaxy!
7) Taurids
Peaking on the morning of November 4, the Taurids come from Encke’s comet, the comet with the fastest orbital period (3.3 years) of any comet. It features some 15 meteors per hour, radiating from Taurus, but since they tend to be bright, the shower appears better than it really is.
8) Leonids
On the 17 of November it is possible to see the maximum of this meteor shower. Usually the shower is weak, with just a handful of meteors each hour. However, when the shower’s parent comet, Tempel-Tuttle, is nearby, the rates can climb dramatically. In 1833 the sky over England was literally blazing with meteors, and in 1966 over the western United States, observers counted some 40 meteors per second. Although the rates were not as high when the comet returned in 1999, Wendee and I counted 2106 meteors on the night of November 19, 2001, by far the most we had seen in a single night.
9) Geminids
This is the strongest meteor shower of the year. Peaking on December 13, the meteors, coming out of Gemini, can come pretty frequently on a good night. I have seen more than 900 on one particularly dark night. The Geminids come from a comet that died long ago, and which is now known as asteroid 3200 Phaethon. I saw that particular asteroid as it moved through the sky last fall.
10) Ursids
Peaking on December 21, this pre-Christmas meteor shower comes from Comet 8P/Tuttle, one of the nineteenth-century comets Horace Tuttle discovered. The meteors emanate from Ursa Minor, the little dipper.[/one_half_last]
Engraving by Adolf Vollmy depicting the 1833 Leonid meteor storm – based upon an original painting by the Swiss artist Karl Jauslin, that is in turn based on a first-person account of the 1833 storm by a minister, Joseph Harvey Waggoner on his way from Florida to New Orleans. Credit: Public Domain.[maxbutton name=”American Meteor Society Meteor Shower Calendar”] [maxbutton name=”IAU Meteor Shower List”]
